I remember wondering how my PC keeps time after I power it off even though I didn't have internet back in late 2000's and my friend's dad told me about this little battery
We have had to replace a fair few CMOS batteries over time. The last one was a couple of months ago on my dad's gaming laptop from 2016. It started loosing it's timing and knew it was time to get a new battery. People may think it is a minor issue. But it can drive you crazy. Especially when you have to manually keep resetting the time so your certificates for things work. Having it keep coming back on saying it was nearly 100 years in the future, caused the pc to have a fit with the certificates saying they had all exprired. Which meant I had to fight with times for at least 5 minutes to get things set right everytime this happened. Not my idea of fun.
@ERA Are having worked at industry for over 10 years and I have probably had to replace a dozen; they tend to go wrong on systems that aren't turned on very often.
That's the reason why I hate the way to use the cmos for time. NTP is much more reliable, I use NTP on linux but still have the "normal" way on windows and it's driving me nuts, cause every fucking time I want to use windows for gaming, I have to fucking resync the time, just do it on boot up windows, just use NTP please Edit: the solution for the problem is down below, windows uses NTP, but they are stupid
This answered a question I've had for half of my life; "how do devices keep time when turned off". I figured there must be some sort of power source still going. I'm just new to PC hardware so I didn't know that motherboards themselves have a battery in them for that reason.
I saw the battery and I figure it out when the computer reboot to factory settings each time I turned it on and the clock wasn't updated, it turn out to be a faulty battery.
there is similar technology in old cartridge games that keep time. Pokemon in the GBA infamously had a "the internal battery has run dry" error message which basically says it can't keep time anymore, and you had to solder in a new battery in the cartridge to fix it
I'm noooooot 100% sure about this, but smartphones for example, when they shut down at 0% battery, they in fact still have like 5% battery left. That few percents will make sure the time is still kept, and also that the battery doesn't flat out die out. It's really hard to get an absolute empty battery back to life, if possible even. My first smartphone was a Nokia 5530, with Symbian OS, and the thing once got completely dry (long night party, no charger at hand). It's own charger didn't do anything with it, I had to plug it into my PC and somehow (no idea how) that started charging it, but veeeeeeery slowly.
When I added a graphics card to a dell, I saw the battery and assumed it’s for time since digital watches use crystal oscillators. Another reason I assumed it’s for time is because timing is important for a computer. If it doesn’t have a clock, how does it keep track of its clock cycles.
@@jakejakedowntwo6613 There are unique clock generator circuits for that iirc. You can boot up a machine without a battery, it just won't have BIOS settings saved or will be reseted, as seen in the video
Nice video. I'd have liked some mention to laptop nvram chips and how the absence of a default "clear BIOS settings" mecanism in laptops can turn into a real hell if you need to enter the BIOS of a password protected laptop.
@@eudofia there's no battery in laptops! Nothing to remove. You have to enter a specific combination of keys/buttons which then leads you to a specific code that you have to write down, and then you have to contact the manufacturer with that specific code -you need to be a registered customer- and then, after checking that you are indeed a customer and the owner of the laptop, they will give you a reply code that you must enter to enter the BIOS. Something like that, I'm talking from memory, it's been a long time.
@@mbc07 if that is true, I have been unlucky then! Had this problem with a couple of models, the only ones I ever came across which were password protected 🤦🏻♂️
My first IBM-compatible PC, a Tandy 1000, did not include a battery. There was no built-in timekeeping, and no BIOS settings. For timekeeping I needed an ISA expansion card (with its own battery), which also upgraded my RAM from 128KB to 640KB. The '80s were fun times. 🙂
At times even the clear_CMOS button/jumper fails to function in a thorough manner, never assume it worked properly. Removing the battery is still the only sure way to reset EFI settings in a thorough and reliable way. I don't know why, but my guess is that EFI initialization crashes or freezes in such a manner that the clear_CMOS jumper/button cannot obtain access to clear whatever errored bits crashed the EFI. Perhaps certain specific EFI settings bits relay power or interfere with the relay of power? Would be interesting to get an answer to this from an engineer at American Megatrends.
It depends on the type of memory used. If its CMOS, then removing power will reset it. For nvme, it will not work, but there is usually a pin on the memory chip that is used to reset the entire thing. For some nvmes there is no global reset button, so you need a circuit that will do it programically, and the last group is the hardest to reset, and the most likely to get perma-failed, so its usually paired with double bios chips where one bios is used for normal operation and the other bios is used only for clearing and fixing the first bios.
One issue may be that it's 2 separate mechanisms to check the jumper vs if the CMOS battery has been pulled. The jumper is a GPIO that's pretty basic to read. For the battery mechanism, the BIOS needs to put some sort of magic value in the CMOS RAM and check if it's still there on boot. Lets assume that AMI has things set up so that these two mechanisms are checked at the same time and trigger the same behavior. The OEM might decide to change things for some reason. Why? Who knows. But what might be more likely is that the circuitry retains enough power to keep the CMOS RAM contents intact. One school of thought is to make sure the battery is removed for a good 30 seconds before trying to reinsert it. Another I've seen is to put the battery in backwards, remove it, then put it back correctly. The idea is to try and drain any capacitors in the power supply circuit so the memory loses power faster.
Not always, I tried the jumper and removing the cmos battery, settings are kept, the only thing reset is time. Seems Lenovo doesn't reset the nvram upon battery removal
@@hubertnnn had it been a problem, the hardware engineers and lab techs at a number of the big hardware companies I have worked for would have had a fit, boards would have been dying left and right because QA, BIOS engineers, and various other systems engineers would regularly flash new BIOS and more than a few of those people would do this as part of their ‘new BIOS ritual’. But it was never a problem. No boards ever died from putting in the CMOS battery backwards. Why? Probably because the RTC circuits used an LDO with reverse polarity protection to supply power to the RTC when on battery. But there is an additional protection mechanism in the physical form factor of a CR2032. If you reverse it, both terminals will connect to positive terminal of the battery which just shorts the power supply input and will drain the capacitors. Other electronics? Be mindful of polarity although any design meant for production should take into account potential end user error and prevent casual reverse polarity issues via mechanisms like physical form factor, reverse polarity protection circuits, etc.
I dont think the one in the display picture would last long though. Its literally a dollar store Maxell knockoff battery. Unless they comissioned them from Maxell themself to make brandless ones for the board. But i doubt it haha
@@drunkpaulocosta no seriously... ive dealt with hundreds of all different types of motherboards... and no matter how old or burnt out the motherboard... somehow that damn battery still works... lol it's amazing really...
@@ZenRyoku Not too surprising, if I remember right they're rated for 7-10 years. I have a bunch of old 90's PCs though that have been through 3-4 batteries, so they do eventually go but they last so long most people never see it happen. They do sometimes swell prematurely though but that's also rare. Also beats the predecessor 'barrel' batteries that loved to corrode the motherboard when they went bad or the Dallas ones that made you replace an entire module when it went dead.
I once got this 386 workstation, with all the things attached to it, including an IBM Proprinter-I, rather blocky mouse, and things like that for free as that thing had been just sitting in a corner for quite some time. For most parts everything was in perfect working order... But the lithium metall (!) battery was dead. You could still use it, as long as you would just set all the drives... As back then stuff like clock speeds and multipliers were mostly set by jumpers, but plug & play sort of hard drives didn't exist... But it was fairly simple to do, especially after doing it a couple of times. I could actually do all the settings and get DOS running in less than half the time it took for modern computer (at the time) to load Windows. But usually I didn't bother setting time and date, so that old computer was usually re-living 1988, I don't really know why did it allways return to that specific year, but it soon became a part of it's whole being... Being such an old computer, having a slight case of dementia didn't seem that wrong. After all, I did use it for some classic games or tinkering a little something with QBasic, all a bit 1980's sort of things to do... Although might be that the computer didn't see my games as very "classic" or "retro", allways thinking it is still 1988, but the point was to have fun and that we had.
In the early ’00s and 90ies switching this battery sometimes was a magical fix for weird problems (such as random shutdowns, temporary black screens etc) in old systems. Which begs the question if low voltage on this battery could cause unexpected issues in miscellaneous subsystems or if removing it just blasted some bad setting in CMOS or similar.
I like how there's always something to learn from these videos, even when I feel like I already know the topic. You do a really good job at educating people new to PCs while also giving experienced people an interesting fact or two. I always thought that telling people to reset their CMOS was a bit stupid, because the people asking for help in situations like that are often new builders who have no idea what that means. Now I know that it's stupid for another reason. The BIOS isn't even stored on the CMOS chip!
I've had a fair few CMOS cells run out on me in my time. I tend to keep computers long enough that this becomes a concern. My old gaming laptop needs one, and the last laptop I had open for a general service got a new one out of precaution. Click below the fold for a history lesson and personal anecdote. Fun fact, waaaaaaaay back in the old days when processors were known by numbers, our CMOS batteries were NiCd! Because we didn't really have lithium cells yet, and physically couldn't store a long amount of power on the board. So MB manufacturers just *recharged* the battery whenever the system was on. These PCs would lose their settings within a few months to a year if you left them powered off. You could buy an alkaline battery pack to connect to an external jumper, that would last ..... I think mine made 20 years before running out? I upgraded it to a lithium coin cell. These things have since just become motherboard murderers though, as any motherboard old enough to still have a NiCd CMOS battery is also old enough for that battery to have failed and begun leaking caustic substances, corroding away traces rather rapidly. Both my 386 and 486 motherboards have had this happen, as has my Amiga 500's expansion RAM card - the 486's battery having even *exploded* before I got the PC! I had to solder new wires on my 386 to repair it (Try that with a modern board...), and the Amiga RAM card needs .... a lot of help. Though I do have a very late model 486 motherboard with a coin cell, so you aren't likely to encounter one of these relics of computing past unless you're truly passionate about retro computers. And if you do happen across one, get with somebody who knows how to solder immediately to have it removed or replaced! Also, recycle the old battery properly. Cadmium is nasty stuff. --- NEVER directly replace a NiCd with a lithium coin! The charging system is still active, and will quite happily explode your brand new coin cell, possibly taking your antique computer with it. Consult your motherboard's manual or other resource to locate a jumper to disable the charging system before installing a non-rechargeable battery. You may need to just wire it in to a separate jumper header intended for the purpose...
@@FerralVideo I came to the comments to check for any comments exactly like this! Those of us in the retro PC space have a biiiiit of a different experience with batteries ahaha Always remember to check your old tech for those bloody barrels!
Did they have boot problems? I was not able to boot my PC from just resetting the cmos, but when I replaced the battery it magically came to life, beyond confused how that could be the case.
@@jaredchampagne2752 Probably a "Y3K" or similar invalid date bug. On UEFI systems, the RTC datetime is kept separately from the UEFI settings, and the so-called "Clear CMOS" jumper will often only clear the UEFI variable store, but not reset the RTC. ("CMOS" really doesn't exist on a modern machine.) Replacing the battery forced the RTC date to reset to a sane default, thus getting out of the buggy state.
Fun fact, some laptops don't need a CMOS battery, they can also use the systems primary battery to run the RTC when no CMOS battery is present. This is how all laptops should do it and just not have a CMOS battery to die or leak at all.
Probably worth mentioning that a lot of security, encryption, and login stuff nowadays absolutely requires correct time. A lot of keys that are generated have a time-based element to them or have expirations. If you're having weird login or security issues, check your time! If your time doesn't stick after reboots or drifts, check your CMOS battery!
many computers except tablets and phones which are SBC based have a CMOS battery that not only keeps time but also in some cases keep the TPM chip settings saved. This means that taking out the CMOS would reset the bios completely as it was even before OEM setup.
That clock battery is actually the way most old games used to save or even keep track of time as well, not just PCs. Pokémon Gold/Silver/Crystal was probably the most popular example of the latter back in the day, having a full day-night cycle that depended on the time you put in at the start of the game.
3:04 Saying NTP is not used for home PCs is completely wrong. Every PC out of the box is configured to use NTP. This is standard on Windows, Linux, and macOS. This is one of the key parts of specifying your location during setup of the OS/user settings. For Windows, the default NTP server is likely set by default to "time.windows.com" which is of course, Microsoft's time server. However, you can specify your desired time server manually, and if so inclined, serve your own time via an NTP server. The point of having an RTC (real time clock) battery is to allow functions such as "wake by RTC" if you have a system which you want power on automatically at some scheduled time, run some task, and then maybe shutdown afterwards, keeping energy usage to a minimum. Another use for it would be to remove the requirement to have internet connection to keep some form of time. Some form of time sync is important if you want to avoid having to manually make adjustments to your clock for things like DST, time zone changes while travelling, or jitter (which means that your local clock is non-ideal and typically will be comprised of some amount of "periodic jitter" meaning it will be consistently slower or faster than the perfect clock).
Exactly, It made me wonder if he was wrong when he said the oposite. I know what you're saying is true cause once I was too lazy to change the battery I just set the internet time on my computer and actually use it without any trouble for months, the time would sync in a matter of seconds as soon as the Desktops loads in...
You have to have an OS running to query NTP as you describe it. The BIOS isn't an operating system and isn't expected to have network access. The OS will generally correct the time of the RTC once the OS starts since there are standard mechanisms to do so. But the the BIOS cannot query an NTP server to set the clock since it's generally not expected to have network access. On servers, one way to set the time set via an embedded microcontroller called the BMC. This will have a dedicated network connection that is used to allow a server to be managed remotely. BMCs generally run an embedded Linux so it's pretty trivial for them to query an NTP server. Then there will be some sort of communication method that allows the BIOS to query the BMC for the current time and to set it.
@@splynncryth You are correct, however I would like to add that BIOSs (both Classic™ and UEFI), though not expected, have been able to utilize network access for a few decades; hence PXE. There is no reason why a modern BIOS couldn't communicate via NTP and update the time before booting. I mean, I'm glad it's not common, but in this day and age where Windows 11 Pro is basically required to have an internet connection to create a user account upon setup, I wouldn't expect motherboard manufacturers to not require a subscription service to keep their BIOS updated and time synchronized.
@@robspiess I can't recall a network stack on Core 8. Taking a quick look at the specs before UNDI, they would have been painful to work with in ASM BIOS and there wasn't universal support. I can't speak for any Phoenix products though. Might you be thinking of PXE boot? PXE boot works via an independent mechanism outside of BIOS. It's been years since I worked with the BBS spec so I don't recall if it generally used int19 or used a different mechanism to load a small 'boot sector' and booted like a floppy or hard disk. Perhaps you encountered a board running Aptio 3 or Aptio 4 where a lot of effort was put into making the firmware look and feel like a legacy product? Those could have a network stack since they were UEFI compliant products. But none of those are 2 decades old yet (the original EFI spec is just turning 20 this year). One solid reason I can think for not wanting your BIOS to have its network stack enabled and update the RTC via NTP at boot is that it increases the attach surface of the firmware.
@@splynncryth PXE is a black box to the BIOS. They are just binaries built into the BIOS or loaded off the PCI card like an option rom. EDK II has a network stack. I am sure it is possible to implement NTP but AFAIK it isn't a standard feature.
Man, I'm so glad LTT ppl do 2k videos. Recently bought a 2k monitor and looking at a 2k video footage right after a normal 1080p one makes the difference really noticeable.
Not all computer motherboards have used or currently use a button cell battery to maintain the CMOS/clock settings, especially earlier PC’s, Macs, and certain other microcomputers. For those computers that had an on-board CMOS/Clock to maintain, some used small tube-shaped 3.6v Lithium 1/2 AA batteries. Sometimes the CMOS battery was soldered onto the motherboard though iusing battery holder so you couldn’t just pop the battery out to replace it. Sometimes laptops used a button cell shaped battery that had wires soldered to it then soldered to the motherboard though again of you were lucky it used a connector so you could easily unplug the battery to replace it. I suspect that in some cases the manufacturer never expected the machine to in use long enough to need to replace the CMOS battery so they simply soldered it on. It seem that at some point, PC motherboards seem to have coalesced on using button cell batteries in holder that allows for easy replacement of the battery when needed. Soldered on batteries are a particular problem for retro computer collectors as the batteries will eventually leak and damage the motherboard due to the battery acid. That’s why if you have an old computer with a CMOS battery that has yet to leak and your storing the computer away, or it’s the battery is simply old then you should remove the battery to be safe. If it’s soldered on then desolder it and replace it with a battery holder that allows you remove the battery when storing the computer away and to make it easier on yourself when replacing later on. Always replace very old batteries on old computers with new one regardless since you never know when they will start to leak and they will leak at some point, mark my words. .
If you have an old Apple Macintosh you might run into a tricky battery problem. It's been a long time since I handled one of these so I can't remember the model. Thing is the machines power button was on the keyboard. But it wasn't powered by standby power like they usually are on a PC, but instead there were a lithium cell inside the keyboard. If this ran dry then you couldn't turn on the computer. I had a customer bring in one of these when it refused to start. We didn't work on Apples machines but he asked us to take a look. My colleague opened up the keyboard to see if the switch might be broken and he was pretty surprised when he found a lithium cell inside. When it measured in at about one volt he replaced it and suddenly the machine worked again. Another fun thing was that the motherboard in this Mac was manufactured by LG-Electronics, or if it was still called Goldstar. Actually that might just have been the PCB in the keyboard that was made by Goldstar. It's been so long I can't remember. I do however know that a portable Mac (PowerBook 100 or possibly 140 - 180) was manufactured for Apple by Acer.
Funny story… back in 1994 I was driving from Chicago to Minnesota, during a blizzard, during spring break. The cell phone my parents gave me for emergencies rang. The emergency? The cmos battery died on our home computer and I was the tech support. My dad thought it was my fault, argued with me until he heard me yell “Oh Shit!” Three times. I crashed into a side rail because of the snow. Fun times. No one was hurt except the turning light on the front right of my ‘81 Toyota Tercel.
Back in the 90s my dad use to have a "security password" so I couldnt play when he wasnt home, and I discover that removing that will remove the password, but the time too, but I figerit out and chage it back. I was like 8
I once had a coworker forget their BIOS password, it was amazing how easy it is to remove that battery, wait half a day, and log back into a computer bypassing the password. Physical security is real 😢
@@itsTyrion I veered on the side of caution waiting for all the capacitive charge to dissipate, it was my first and only time doing that so I didn't know what to expect 😂
I can tell you first hand what happens when the battery goes bad. Random BSODs and weird BIOS behavior like it doesn't save settings yet doesn't tell you so. Very hard to debug, but easy to solve.
I had the same issue with random BSODs and start up issues. Had some spare batteries so I swapped them out. Boom, no more blue screen and start up issues.
128 bytes isn't always 128 characters. I would add ASCII before characters because a Unicode character may not be one byte. Hence why low level languages handling strings are scary sometimes as you can incorrectly address the string a way it wasn't meant to be read.
String handling is really tricky , rust language has 8 char and string types for instance. There was no reason in low lowel to account for encoding non ascii char hence it might look weird. Languages like C# has 2 bytes allocated for character. I wish there was an standard guide line.
@@sps014 and the real kicker is, even those 2-byte characters are not enough to encode all Unicode characters, and the language has exceptions when you attempt to sever a surrogate pair (which encodes one character in 4 bytes). There is a way to encode all Unicode characters in 4-byte characters called UTF32, but that takes so much memory just so you can cover for infrequent characters.
Well wen talking about the NVRAM used for the setup you can feel pretty certain there's no Unicode chars stored in it. Instead a lot of settings are stored as single bits instead of wasting memory by using an entire byte... Now if you are talking about UEFI, which isn't really BIOS but it's successor, then I guess there may be some Unicode characters used in the configuration.
NTP is *DEFINITELY* used on home PCs. What do you think is happening under the hood when Windows synchronizes the clock with "internet time" Plus. Many servers do still keep an internal clock and a battery, but NTP time is preferred, with local time being a backup source.
We were actually talking about how Windows client machines typically don't use the UEFI network stack to connect to an NTP server at boot time, rather than the time service inside Windows. Our apologies if that was not clear. Thank you for watching!
@@techquickie awesome! I gotcha now. Although it bears noting that the OS clock will often update the hardware clock also, if enabled (usually by default)
@@StrokeMahEgo Secure Boot certificates have valid date range. So if you are using a UEFI OS with Secure Boot enabled and the CMOS date gets corrupted or reset to a default outside of that certificates range then the BIOS wont let you boot the OS and if you cant boot the OS then the OS can't fix the time.
Heh, quite a fair amount of motherboards these days, like ASUS hide the CMOS battery behind fancy panels, making it a nightmare to remove if there's a reason to do so.
Only For Fans Over 18 Years Old↷ᶜˡⁱᶜᵏˡⁱⁿᵏ👇 (◍•ᴗ•◍) KOOTONANOKSAI.XYZ/Anggeline?AV-jK✰ 𝕤𝕖𝕟𝕤𝕚𝕥𝕚𝕧𝕖 𝕔𝕠𝕟𝕥𝕖𝕟𝕥 💦 Megan: "Hotter" Hopi: "Sweeter" Joonie: "Cooler" Yoongi: "Butter" Asi con toy y sus mañas no se la lease que escriba bien mamon hay nomas pa ra reirse un rato y no estar triste y estresado.por la vida dura que se vive hoy . Köz karaş: ''Taŋ kaldım'' Erinder: ''Sezimdüü'' Jılmayuu: ''Tattuuraak'' Dene: ''Muzdak'' Jizn, kak krasivaya melodiya, tolko pesni pereputalis. Aç köz arstan Bul ukmuştuuday ısık kün bolçu, jana arstan abdan açka bolgon. Uyunan çıgıp, tigi jer-jerdi izdedi. Al kiçinekey koyondu gana taba algan. Al bir az oylonboy koyondu karmadı. ''Bul koyon menin kursagımdı toyguza albayt'' dep oylodu arstan. Arstan koyondu öltüröyün dep jatkanda, bir kiyik tigi tarapka çurkadı. Arstan aç köz bolup kaldı. Kiçine koyondu emes, çoŋ kiyikti jegen jakşı dep oylodu.#垃圾
The good ones tend to have cmos clear buttons, But otherwise you can just jump the cmos connections on the board with a metal object if you can't get to the battery :)
You should remove the battery from your computer if you're thinking on storing it for a long time, and if you bought an old computer that has it, you should check it up immediately. After many years, they tend to leak badly all over your PCB.
I actually wrote my current RAM timings into the XMP profile, that way if I ever have to replace the battery or even the whole motherboard, I can just enable XMP and it's back to normal
We opened up the PS4 and we saw this installed in the Motherboard. ✌️ Had to replace one on my Truck Keys Remote Locker / Unlocker and the Motherboard. 😯
Great video , one computer that comes to mind that does not have a RTC is the raspberry pi. The ironic thing is that I have a pi4 running Ubuntu as a local ntp server.
Thankfully my CMOS didn't clear when I removed my CMOS battery but an easy way to know it's time to replace it is when your PC starts losing time (especially if you have it set to not fetch time from the internet). You'll first notice this when a program breaks or a browser page or log in something doesn't want to work. After 7yrs of service, mine was due.
It really sucks when your CMOS battery dies and you can’t boot into your PC anymore, but aren’t sure why. Took me hours to realize that the CMOS battery was dead, and that the issue was in the BIOS settings.
I have a vintage motherboard in storage that uses jumpers for settings instead of a BIOS menu system. It's got jumpers all over the motherboard with labels for each. Funky stuff.
Complimentary : expressing a compliment; praising or approving. Complementary: combining in such a way as to enhance or emphasize the qualities of each other or another. Complementary metal-oxide-semiconductor (note the hyphens) is the correct form. BTW the Metal-Oxide-Semiconductor describes the 3 basic layers of the construction (originally Aluminium now polysilicon, Silicon dioxide , doped silicon), not some mythical Semiconductor that is a metal oxide.
The CR2032 in my copy of Chrono Trigger is 25 years old. And it's held the save data all these years. My best guess is it's easier for such a battery to simply hold data in place than it is for such a battery to run a clock for upwards of a decade.
Only For Fans Over 18 Years Old↷ᶜˡⁱᶜᵏˡⁱⁿᵏ👇 (◍•ᴗ•◍) KOOTONANOKSAI.XYZ/Anggeline?AV-jK✰ 𝕤𝕖𝕟𝕤𝕚𝕥𝕚𝕧𝕖 𝕔𝕠𝕟𝕥𝕖𝕟𝕥 💦 Megan: "Hotter" Hopi: "Sweeter" Joonie: "Cooler" Yoongi: "Butter" Asi con toy y sus mañas no se la lease que escriba bien mamon hay nomas pa ra reirse un rato y no estar triste y estresado.por la vida dura que se vive hoy . Köz karaş: ''Taŋ kaldım'' Erinder: ''Sezimdüü'' Jılmayuu: ''Tattuuraak'' Dene: ''Muzdak'' Jizn, kak krasivaya melodiya, tolko pesni pereputalis. Aç köz arstan Bul ukmuştuuday ısık kün bolçu, jana arstan abdan açka bolgon. Uyunan çıgıp, tigi jer-jerdi izdedi. Al kiçinekey koyondu gana taba algan. Al bir az oylonboy koyondu karmadı. ''Bul koyon menin kursagımdı toyguza albayt'' dep oylodu arstan. Arstan koyondu öltüröyün dep jatkanda, bir kiyik tigi tarapka çurkadı. Arstan aç köz bolup kaldı. Kiçine koyondu emes, çoŋ kiyikti jegen jakşı dep oylodu.#垃圾
Yes, this is the reason Pokemon Gold and Silver's saves only last 2 to 3 years. The battery inside the cartridge doesn't only keep saves, it also runs the internal clock that ticks even when your cartridge isn't plugging in. So every couple years it dies and when it dies there goes the save. (as you can imagine it's a smaller battery than the one on a motherboard).
@@PINKEDASHPT so I've heard. Makes me wonder how long the batteries for my Raspberry Pi RTCs are gonna last, but those are at least easily replaceable.
My motherboard (ASRock B550 Phantom Gaming 4) actually has two pins on it called a "CMOS Jumper." Basically I just touch them with a flathead screwdriver, and that resets my BIOS. I had to use it while I was initially building my computer because it wasn't booting correctly. Which is good, because I found the CMOS battery on the board pretty difficult to remove.
Only For Fans Over 18 Years Old↷ᶜˡⁱᶜᵏˡⁱⁿᵏ👇 (◍•ᴗ•◍) KOOTONANOKSAI.XYZ/Anggeline?AV-jK✰ 𝕤𝕖𝕟𝕤𝕚𝕥𝕚𝕧𝕖 𝕔𝕠𝕟𝕥𝕖𝕟𝕥 💦 Megan: "Hotter" Hopi: "Sweeter" Joonie: "Cooler" Yoongi: "Butter" Asi con toy y sus mañas no se la lease que escriba bien mamon hay nomas pa ra reirse un rato y no estar triste y estresado.por la vida dura que se vive hoy . Köz karaş: ''Taŋ kaldım'' Erinder: ''Sezimdüü'' Jılmayuu: ''Tattuuraak'' Dene: ''Muzdak'' Jizn, kak krasivaya melodiya, tolko pesni pereputalis. Aç köz arstan Bul ukmuştuuday ısık kün bolçu, jana arstan abdan açka bolgon. Uyunan çıgıp, tigi jer-jerdi izdedi. Al kiçinekey koyondu gana taba algan. Al bir az oylonboy koyondu karmadı. ''Bul koyon menin kursagımdı toyguza albayt'' dep oylodu arstan. Arstan koyondu öltüröyün dep jatkanda, bir kiyik tigi tarapka çurkadı. Arstan aç köz bolup kaldı. Kiçine koyondu emes, çoŋ kiyikti jegen jakşı dep oylodu.#垃圾
I came across several Microsoft Surface devices that lost their clocks when they were powered off. They were old, so I suspected that their clock batteries had gone bad. We couldn't replace them, though.
They use the built in battery. Mobile devices besides laptops with externally removable batteries don't have CMOS batteries. If a surface is not keeping time, it would be another issue, like the RT clock itself.
@@wecsam Yeah. I would check to make sure its not a software issue though, because having an RT clock go out with the rest of the logic board still working is rare, though not unheard of.
@@wecsam The piezoelectric oscillators that are used to make the base clock which the core clock is a multiplier of are usually high quality, but the ones used for the clock are often off the shelf, sometimes literally. I have a couple of dell dimensions and all of them use a little metallic cylinder with two transverse leads that are exactly the same ones used in cheap clocks. They got a little quartz crystal in them, and are often not made to the same quality as motherboard oscillators since they are going in to cheap mass produced clocks. The ones used for the motherboard base clock are usually packaged in a small dual in line package and usually use germanium rather than quartz as the piezoelectric element, and are of higher quality. Gigabyte boards and asus boards particularly have been known to use high quality oscillators for the RT clocks that were manufactured specifically for their motherboards, the same way as the ones for the base clock. While it's rare for any oscillator to fail on a board, the clock ones are more likely to do so if they are this cheaper kind. And unlike the motherboard oscillator it wont make the whole thing fail, just the RTC function.
Only For Fans Over 18 Years Old↷ᶜˡⁱᶜᵏˡⁱⁿᵏ👇 (◍•ᴗ•◍) KOOTONANOKSAI.XYZ/Anggeline?AV-jK✰ 𝕤𝕖𝕟𝕤𝕚𝕥𝕚𝕧𝕖 𝕔𝕠𝕟𝕥𝕖𝕟𝕥 💦 Megan: "Hotter" Hopi: "Sweeter" Joonie: "Cooler" Yoongi: "Butter" Asi con toy y sus mañas no se la lease que escriba bien mamon hay nomas pa ra reirse un rato y no estar triste y estresado.por la vida dura que se vive hoy . Köz karaş: ''Taŋ kaldım'' Erinder: ''Sezimdüü'' Jılmayuu: ''Tattuuraak'' Dene: ''Muzdak'' Jizn, kak krasivaya melodiya, tolko pesni pereputalis. Aç köz arstan Bul ukmuştuuday ısık kün bolçu, jana arstan abdan açka bolgon. Uyunan çıgıp, tigi jer-jerdi izdedi. Al kiçinekey koyondu gana taba algan. Al bir az oylonboy koyondu karmadı. ''Bul koyon menin kursagımdı toyguza albayt'' dep oylodu arstan. Arstan koyondu öltüröyün dep jatkanda, bir kiyik tigi tarapka çurkadı. Arstan aç köz bolup kaldı. Kiçine koyondu emes, çoŋ kiyikti jegen jakşı dep oylodu.#垃圾
While you imply they are not needed, servers in datacenters do have the same CR2032 coin cell battery on board. So do the network switches and chassis managers. You will spot them in hardware teardowns on ServeTheHome, and in Open Compute server documentation. I'm curious if anyone knows of exceptions - a server (not RPi or SBC) with no CR2032.
Basically, its a CMOS battery, which is needed for storing BIOS settings on motherboards. These batteries are not needed for your PC anymore for BIOS settings anymore, *BUT* they are needed for time settings on home computers.
They didn’t always use a coin cell battery. Older computers used whatever they pleased, from +6V batteries, to AA, to the dreaded Dallas RTC chip with a built in battery that was often soldered in (requiring a replacement or DREMELING THE HOUSING TO ADD A COIN CELL BATTERY)
Had to change this battery about a year ago because in windows the time would not show correctly. Wish this video had been out then, would have saved me some time!
Only For Fans Over 18 Years Old↷ᶜˡⁱᶜᵏˡⁱⁿᵏ👇 (◍•ᴗ•◍) KOOTONANOKSAI.XYZ/Anggeline?AV-jK✰ 𝕤𝕖𝕟𝕤𝕚𝕥𝕚𝕧𝕖 𝕔𝕠𝕟𝕥𝕖𝕟𝕥 💦 Megan: "Hotter" Hopi: "Sweeter" Joonie: "Cooler" Yoongi: "Butter" Asi con toy y sus mañas no se la lease que escriba bien mamon hay nomas pa ra reirse un rato y no estar triste y estresado.por la vida dura que se vive hoy . Köz karaş: ''Taŋ kaldım'' Erinder: ''Sezimdüü'' Jılmayuu: ''Tattuuraak'' Dene: ''Muzdak'' Jizn, kak krasivaya melodiya, tolko pesni pereputalis. Aç köz arstan Bul ukmuştuuday ısık kün bolçu, jana arstan abdan açka bolgon. Uyunan çıgıp, tigi jer-jerdi izdedi. Al kiçinekey koyondu gana taba algan. Al bir az oylonboy koyondu karmadı. ''Bul koyon menin kursagımdı toyguza albayt'' dep oylodu arstan. Arstan koyondu öltüröyün dep jatkanda, bir kiyik tigi tarapka çurkadı. Arstan aç köz bolup kaldı. Kiçine koyondu emes, çoŋ kiyikti jegen jakşı dep oylodu.#垃圾
last month i had to replace two bios batteries in our working stations from 2012. apparently the bios battery also controls (gives current/voltage to a) chip which is used for coordinating usb devices and the boot order. this results in an error that the pc trys to boot from any usb device, be it a mouse, stick, or keyboard. -.-
One time I changed the graphics output in my bios to the integrated gpu in my dell precision. ..but it had an intel xeon. If that little battery diddnt exist the system would have been bricked forever.
Dell nowadays use cheaper battery for the RTC. In the 2010-2015 models the battery is 10 years plus life, but since 2016 it runs out juice just after 4-5 years.
I wish that removing the battery to clear cmos (bios settings) was an option that you could disable if you dont want that feature and want it to retain the settings.
CMOS battery .... take it out and watch what happens lol 😆 Another interesting thing is that you can turn on a PSU without a motherboard, you just have to jump two pins on the 24pin connector to "trick" it.
After a power outage my PC would not turn on (power button did nothing), yet the MOBO leds worked fine / power supply did not smell burnt. I was thinking of getting a new PSU since I had no idea what the issue was. Turns out that, on my ROG STRIX Z370-G mobo, if the cmos battery dies... the power button will simply not do anything. Glad I tried swapping the battery, before I got a new PSU.
Oh... so maybe this is why an old laptop our family owned would always have the wrong date and time whenever we turned it on: because the battery was probably dead.
The statement at 2:52 is wrong. Windows and Linux use NTP to keep accurate time. It's not just servers that use NTP. Desktops and laptops use it too. Also, servers still have CMOS batteries (at least the HPE ones I've worked with for many years do). The BIOS in servers does not use NTP. Most of the time, you just allow the host OS (Windows Server, Linux, VMware ESXi, etc.) to set the time. The OS will adjust the RTC (real-time clock) -- the circuit that needs power from the CMOS battery to keep incrementing the time while the computer is off. NTP is necessary no matter what because the RTC is not accurate. The time kept by the RTC will drift over time, so computers need to query NTP servers because the NTP servers get their time from atomic clocks. Atomic clocks are far more accurate.
As an Electronics Engineer who works with digital semiconductor design. When someone starts talking to me about CMOS it throws me off every time that they’re just talking about a nvrm for bios. Like, most of the board is CMOS. lol
what in the... i literally was just looking at the CMOS battery of my motherboard, and thinking "why does it need that?" and few hours later, got this video recommended.
If that battery dies it's a pain in the ass especially in a custom built PC. All the BIOS settings will be reset as soon as the power is turned off. Luckily Asus BIOS allows you to save profiles which are non-volatile but it's still troublesome to load it every single time it boots.
Make sure to buy the battery from a store which have the latest manufacturer item as I bought this battery from a radom electronic store the battery had around 2.8v and my computer need 3.3v and that was frustrating to fix
The computers I have had over decades of which I typically keep for over 12 years have never had a battery issue. I am confused though about - if a computer is either left on 24/7 or mostly left in Sleep mode 99% of the time, does the regular power supply take over from the battery thus greatly extending it's life? I always wondered as to why a battery can last 12 years or more. Thanks
Recetnly the battery died and i was really wondering why my PC stop working lol. It was a 10-13 year old PC/battery sooo yeah. If people still use an old PC and it suddenly stop working or booting, it could be that. Don't panic like i did ;p
![BOWKYLION - วิงวอน (ex-change) [Official MV]](http://i.ytimg.com/vi/cLdnZWDaO-w/mqdefault.jpg)
![[#2024MAMA] ROSÉ (로제), Bruno Mars - APT. | Mnet 241122 방송](http://i.ytimg.com/vi/dgGqD28J6aQ/mqdefault.jpg)
![[MV] A leap of faith...ความเชื่อใจครั้งสุดท้าย (From "Petrichor the series")](http://i.ytimg.com/vi/U1piZH2CNXA/mqdefault.jpg)
I remember wondering how my PC keeps time after I power it off even though I didn't have internet back in late 2000's and my friend's dad told me about this little battery
The more you know
Yeah, I didn't believe my dad at first. But then it's working again after I replace the battery.
Yeah, my old pc's time also kept resetting to 1 January, 2008. I believe that also happened because the cmos battery died.
I thought more modern computers just check the time online. But its this little guy on my motherboard that keeps track of time.
How does my nintendo gamecube still accurately display the current date? It has no internet connection and no battery as far as I can tell.
We have had to replace a fair few CMOS batteries over time. The last one was a couple of months ago on my dad's gaming laptop from 2016. It started loosing it's timing and knew it was time to get a new battery. People may think it is a minor issue. But it can drive you crazy. Especially when you have to manually keep resetting the time so your certificates for things work. Having it keep coming back on saying it was nearly 100 years in the future, caused the pc to have a fit with the certificates saying they had all exprired. Which meant I had to fight with times for at least 5 minutes to get things set right everytime this happened. Not my idea of fun.
been 10 years i didnt touch any cmos battery + i didnt get issues with time
@ERA Are having worked at industry for over 10 years and I have probably had to replace a dozen; they tend to go wrong on systems that aren't turned on very often.
I wonder why they don’t just replace it with a small rechargeable battery that can get charged while the computer is running?
one of my laptops still says it's 2009 lmao
That's the reason why I hate the way to use the cmos for time. NTP is much more reliable, I use NTP on linux but still have the "normal" way on windows and it's driving me nuts, cause every fucking time I want to use windows for gaming, I have to fucking resync the time, just do it on boot up windows, just use NTP please
Edit: the solution for the problem is down below, windows uses NTP, but they are stupid
This answered a question I've had for half of my life; "how do devices keep time when turned off".
I figured there must be some sort of power source still going. I'm just new to PC hardware so I didn't know that motherboards themselves have a battery in them for that reason.
I saw the battery and I figure it out when the computer reboot to factory settings each time I turned it on and the clock wasn't updated, it turn out to be a faulty battery.
there is similar technology in old cartridge games that keep time. Pokemon in the GBA infamously had a "the internal battery has run dry" error message which basically says it can't keep time anymore, and you had to solder in a new battery in the cartridge to fix it
I'm noooooot 100% sure about this, but smartphones for example, when they shut down at 0% battery, they in fact still have like 5% battery left.
That few percents will make sure the time is still kept, and also that the battery doesn't flat out die out. It's really hard to get an absolute empty battery back to life, if possible even.
My first smartphone was a Nokia 5530, with Symbian OS, and the thing once got completely dry (long night party, no charger at hand).
It's own charger didn't do anything with it, I had to plug it into my PC and somehow (no idea how) that started charging it, but veeeeeeery slowly.
When I added a graphics card to a dell, I saw the battery and assumed it’s for time since digital watches use crystal oscillators. Another reason I assumed it’s for time is because timing is important for a computer. If it doesn’t have a clock, how does it keep track of its clock cycles.
@@jakejakedowntwo6613 There are unique clock generator circuits for that iirc.
You can boot up a machine without a battery, it just won't have BIOS settings saved or will be reseted, as seen in the video
Nice video. I'd have liked some mention to laptop nvram chips and how the absence of a default "clear BIOS settings" mecanism in laptops can turn into a real hell if you need to enter the BIOS of a password protected laptop.
So, what do in that case? Remove the battery and wait for a few seconds to clear the CMOS?
@@eudofia there's no battery in laptops! Nothing to remove. You have to enter a specific combination of keys/buttons which then leads you to a specific code that you have to write down, and then you have to contact the manufacturer with that specific code -you need to be a registered customer- and then, after checking that you are indeed a customer and the owner of the laptop, they will give you a reply code that you must enter to enter the BIOS. Something like that, I'm talking from memory, it's been a long time.
@@mkcristobal most laptops still have a lithium cell battery to keep track of time, even current models...
I just guessed the password
1234 was the default
@@mbc07 if that is true, I have been unlucky then! Had this problem with a couple of models, the only ones I ever came across which were password protected 🤦🏻♂️
My first IBM-compatible PC, a Tandy 1000, did not include a battery. There was no built-in timekeeping, and no BIOS settings. For timekeeping I needed an ISA expansion card (with its own battery), which also upgraded my RAM from 128KB to 640KB. The '80s were fun times. 🙂
@@Velocifyer From 128KB to 640K by adding 512KB via memory expansion board.
At times even the clear_CMOS button/jumper fails to function in a thorough manner, never assume it worked properly. Removing the battery is still the only sure way to reset EFI settings in a thorough and reliable way. I don't know why, but my guess is that EFI initialization crashes or freezes in such a manner that the clear_CMOS jumper/button cannot obtain access to clear whatever errored bits crashed the EFI. Perhaps certain specific EFI settings bits relay power or interfere with the relay of power? Would be interesting to get an answer to this from an engineer at American Megatrends.
It depends on the type of memory used. If its CMOS, then removing power will reset it.
For nvme, it will not work, but there is usually a pin on the memory chip that is used to reset the entire thing.
For some nvmes there is no global reset button, so you need a circuit that will do it programically, and the last group is the hardest to reset, and the most likely to get perma-failed, so its usually paired with double bios chips where one bios is used for normal operation and the other bios is used only for clearing and fixing the first bios.
One issue may be that it's 2 separate mechanisms to check the jumper vs if the CMOS battery has been pulled. The jumper is a GPIO that's pretty basic to read. For the battery mechanism, the BIOS needs to put some sort of magic value in the CMOS RAM and check if it's still there on boot.
Lets assume that AMI has things set up so that these two mechanisms are checked at the same time and trigger the same behavior. The OEM might decide to change things for some reason. Why? Who knows.
But what might be more likely is that the circuitry retains enough power to keep the CMOS RAM contents intact. One school of thought is to make sure the battery is removed for a good 30 seconds before trying to reinsert it. Another I've seen is to put the battery in backwards, remove it, then put it back correctly. The idea is to try and drain any capacitors in the power supply circuit so the memory loses power faster.
Not always, I tried the jumper and removing the cmos battery, settings are kept, the only thing reset is time. Seems Lenovo doesn't reset the nvram upon battery removal
@@splynncryth Never put the battery backwards, it can damage the motherboard, even with such a weak power source.
@@hubertnnn had it been a problem, the hardware engineers and lab techs at a number of the big hardware companies I have worked for would have had a fit, boards would have been dying left and right because QA, BIOS engineers, and various other systems engineers would regularly flash new BIOS and more than a few of those people would do this as part of their ‘new BIOS ritual’. But it was never a problem. No boards ever died from putting in the CMOS battery backwards.
Why? Probably because the RTC circuits used an LDO with reverse polarity protection to supply power to the RTC when on battery.
But there is an additional protection mechanism in the physical form factor of a CR2032. If you reverse it, both terminals will connect to positive terminal of the battery which just shorts the power supply input and will drain the capacitors.
Other electronics? Be mindful of polarity although any design meant for production should take into account potential end user error and prevent casual reverse polarity issues via mechanisms like physical form factor, reverse polarity protection circuits, etc.
its so fascinating how long the battery lasts... i have never seen even the oldest motherboards... and they STILL work.
I dont think the one in the display picture would last long though. Its literally a dollar store Maxell knockoff battery.
Unless they comissioned them from Maxell themself to make brandless ones for the board. But i doubt it haha
@@drunkpaulocosta no seriously... ive dealt with hundreds of all different types of motherboards... and no matter how old or burnt out the motherboard... somehow that damn battery still works... lol it's amazing really...
Is the battery being drained when the PC is plugged in or only when its unplugged?
@@ZenRyoku Not too surprising, if I remember right they're rated for 7-10 years. I have a bunch of old 90's PCs though that have been through 3-4 batteries, so they do eventually go but they last so long most people never see it happen. They do sometimes swell prematurely though but that's also rare. Also beats the predecessor 'barrel' batteries that loved to corrode the motherboard when they went bad or the Dallas ones that made you replace an entire module when it went dead.
I've replaced a couple. In one system the clock kept slowing down. Got to the point where it lost a few minutes every day.
Thanks for the update. I am a PC tech but not really looked into this topic as it seem to have not changed. Which I think was a win for manufacturing.
Techquickie: Why Do Motherboards Have Batteries?
Everybody: The user manual says so!
I once got this 386 workstation, with all the things attached to it, including an IBM Proprinter-I, rather blocky mouse, and things like that for free as that thing had been just sitting in a corner for quite some time.
For most parts everything was in perfect working order... But the lithium metall (!) battery was dead. You could still use it, as long as you would just set all the drives... As back then stuff like clock speeds and multipliers were mostly set by jumpers, but plug & play sort of hard drives didn't exist... But it was fairly simple to do, especially after doing it a couple of times. I could actually do all the settings and get DOS running in less than half the time it took for modern computer (at the time) to load Windows.
But usually I didn't bother setting time and date, so that old computer was usually re-living 1988, I don't really know why did it allways return to that specific year, but it soon became a part of it's whole being... Being such an old computer, having a slight case of dementia didn't seem that wrong. After all, I did use it for some classic games or tinkering a little something with QBasic, all a bit 1980's sort of things to do... Although might be that the computer didn't see my games as very "classic" or "retro", allways thinking it is still 1988, but the point was to have fun and that we had.
In the early ’00s and 90ies switching this battery sometimes was a magical fix for weird problems (such as random shutdowns, temporary black screens etc) in old systems. Which begs the question if low voltage on this battery could cause unexpected issues in miscellaneous subsystems or if removing it just blasted some bad setting in CMOS or similar.
I like how there's always something to learn from these videos, even when I feel like I already know the topic. You do a really good job at educating people new to PCs while also giving experienced people an interesting fact or two.
I always thought that telling people to reset their CMOS was a bit stupid, because the people asking for help in situations like that are often new builders who have no idea what that means. Now I know that it's stupid for another reason. The BIOS isn't even stored on the CMOS chip!
4:13 anything for you, Riley boy! _Pegasus' voice_
I've had a fair few CMOS cells run out on me in my time.
I tend to keep computers long enough that this becomes a concern.
My old gaming laptop needs one, and the last laptop I had open for a general service got a new one out of precaution.
Click below the fold for a history lesson and personal anecdote.
Fun fact, waaaaaaaay back in the old days when processors were known by numbers, our CMOS batteries were NiCd!
Because we didn't really have lithium cells yet, and physically couldn't store a long amount of power on the board.
So MB manufacturers just *recharged* the battery whenever the system was on. These PCs would lose their settings within a few months to a year if you left them powered off.
You could buy an alkaline battery pack to connect to an external jumper, that would last ..... I think mine made 20 years before running out? I upgraded it to a lithium coin cell.
These things have since just become motherboard murderers though, as any motherboard old enough to still have a NiCd CMOS battery is also old enough for that battery to have failed and begun leaking caustic substances, corroding away traces rather rapidly.
Both my 386 and 486 motherboards have had this happen, as has my Amiga 500's expansion RAM card - the 486's battery having even *exploded* before I got the PC! I had to solder new wires on my 386 to repair it (Try that with a modern board...), and the Amiga RAM card needs .... a lot of help.
Though I do have a very late model 486 motherboard with a coin cell, so you aren't likely to encounter one of these relics of computing past unless you're truly passionate about retro computers.
And if you do happen across one, get with somebody who knows how to solder immediately to have it removed or replaced! Also, recycle the old battery properly. Cadmium is nasty stuff.
--- NEVER directly replace a NiCd with a lithium coin! The charging system is still active, and will quite happily explode your brand new coin cell, possibly taking your antique computer with it.
Consult your motherboard's manual or other resource to locate a jumper to disable the charging system before installing a non-rechargeable battery. You may need to just wire it in to a separate jumper header intended for the purpose...
Gah! I missed the perfect opportunity for a "Can it run Doom" reference! This was the era when the original Doom came out, after all...
@@FerralVideo I came to the comments to check for any comments exactly like this! Those of us in the retro PC space have a biiiiit of a different experience with batteries ahaha
Always remember to check your old tech for those bloody barrels!
As a repair technician, swapping cmos batteries has fixed a lot more laptops than I would have ever expected when I started.
Did they have boot problems? I was not able to boot my PC from just resetting the cmos, but when I replaced the battery it magically came to life, beyond confused how that could be the case.
@@jaredchampagne2752 Yeah, it has usually been boot problems. We have also had issues caused by date and time errors, usually internet related.
@@djchristian82 Usually it is universal. I'm sure theres some proprietary nonsense somewhere but I've thankfully never run into it.
@@jaredchampagne2752 Probably a "Y3K" or similar invalid date bug. On UEFI systems, the RTC datetime is kept separately from the UEFI settings, and the so-called "Clear CMOS" jumper will often only clear the UEFI variable store, but not reset the RTC. ("CMOS" really doesn't exist on a modern machine.) Replacing the battery forced the RTC date to reset to a sane default, thus getting out of the buggy state.
Fun fact, some laptops don't need a CMOS battery, they can also use the systems primary battery to run the RTC when no CMOS battery is present. This is how all laptops should do it and just not have a CMOS battery to die or leak at all.
Probably worth mentioning that a lot of security, encryption, and login stuff nowadays absolutely requires correct time. A lot of keys that are generated have a time-based element to them or have expirations.
If you're having weird login or security issues, check your time! If your time doesn't stick after reboots or drifts, check your CMOS battery!
many computers except tablets and phones which are SBC based have a CMOS battery that not only keeps time but also in some cases keep the TPM chip settings saved. This means that taking out the CMOS would reset the bios completely as it was even before OEM setup.
That clock battery is actually the way most old games used to save or even keep track of time as well, not just PCs. Pokémon Gold/Silver/Crystal was probably the most popular example of the latter back in the day, having a full day-night cycle that depended on the time you put in at the start of the game.
3:04 Saying NTP is not used for home PCs is completely wrong. Every PC out of the box is configured to use NTP. This is standard on Windows, Linux, and macOS. This is one of the key parts of specifying your location during setup of the OS/user settings. For Windows, the default NTP server is likely set by default to "time.windows.com" which is of course, Microsoft's time server. However, you can specify your desired time server manually, and if so inclined, serve your own time via an NTP server.
The point of having an RTC (real time clock) battery is to allow functions such as "wake by RTC" if you have a system which you want power on automatically at some scheduled time, run some task, and then maybe shutdown afterwards, keeping energy usage to a minimum. Another use for it would be to remove the requirement to have internet connection to keep some form of time.
Some form of time sync is important if you want to avoid having to manually make adjustments to your clock for things like DST, time zone changes while travelling, or jitter (which means that your local clock is non-ideal and typically will be comprised of some amount of "periodic jitter" meaning it will be consistently slower or faster than the perfect clock).
Exactly, It made me wonder if he was wrong when he said the oposite.
I know what you're saying is true cause once I was too lazy to change the battery I just set the internet time on my computer and actually use it without any trouble for months, the time would sync in a matter of seconds as soon as the Desktops loads in...
You have to have an OS running to query NTP as you describe it. The BIOS isn't an operating system and isn't expected to have network access. The OS will generally correct the time of the RTC once the OS starts since there are standard mechanisms to do so.
But the the BIOS cannot query an NTP server to set the clock since it's generally not expected to have network access.
On servers, one way to set the time set via an embedded microcontroller called the BMC. This will have a dedicated network connection that is used to allow a server to be managed remotely. BMCs generally run an embedded Linux so it's pretty trivial for them to query an NTP server. Then there will be some sort of communication method that allows the BIOS to query the BMC for the current time and to set it.
@@splynncryth You are correct, however I would like to add that BIOSs (both Classic™ and UEFI), though not expected, have been able to utilize network access for a few decades; hence PXE. There is no reason why a modern BIOS couldn't communicate via NTP and update the time before booting.
I mean, I'm glad it's not common, but in this day and age where Windows 11 Pro is basically required to have an internet connection to create a user account upon setup, I wouldn't expect motherboard manufacturers to not require a subscription service to keep their BIOS updated and time synchronized.
@@robspiess I can't recall a network stack on Core 8. Taking a quick look at the specs before UNDI, they would have been painful to work with in ASM BIOS and there wasn't universal support. I can't speak for any Phoenix products though.
Might you be thinking of PXE boot? PXE boot works via an independent mechanism outside of BIOS. It's been years since I worked with the BBS spec so I don't recall if it generally used int19 or used a different mechanism to load a small 'boot sector' and booted like a floppy or hard disk.
Perhaps you encountered a board running Aptio 3 or Aptio 4 where a lot of effort was put into making the firmware look and feel like a legacy product? Those could have a network stack since they were UEFI compliant products.
But none of those are 2 decades old yet (the original EFI spec is just turning 20 this year).
One solid reason I can think for not wanting your BIOS to have its network stack enabled and update the RTC via NTP at boot is that it increases the attach surface of the firmware.
@@splynncryth PXE is a black box to the BIOS. They are just binaries built into the BIOS or loaded off the PCI card like an option rom. EDK II has a network stack. I am sure it is possible to implement NTP but AFAIK it isn't a standard feature.
Man, I'm so glad LTT ppl do 2k videos. Recently bought a 2k monitor and looking at a 2k video footage right after a normal 1080p one makes the difference really noticeable.
2k is the same as 1080p. You mean 4k.
@@Sarafan92 It isn't i think. 2k is 1440p
@@Sarafan92 I think they mean "1440p"/"QHD".
@@Sarafan92 2k is not the same as 1080p
They make 4K videos though
had to use the old "remove battery to reset bios" trick just last year! didnt know its just for keeping time now. realy glad it still worked!
love the stock footage of the servers having lights resembling the x360.... hope they dont red ring! :)
I'm so glad it wasn't just me that caught that. Now I want one of those servers!
Not all computer motherboards have used or currently use a button cell battery to maintain the CMOS/clock settings, especially earlier PC’s, Macs, and certain other microcomputers. For those computers that had an on-board CMOS/Clock to maintain, some used small tube-shaped 3.6v Lithium 1/2 AA batteries. Sometimes the CMOS battery was soldered onto the motherboard though iusing battery holder so you couldn’t just pop the battery out to replace it. Sometimes laptops used a button cell shaped battery that had wires soldered to it then soldered to the motherboard though again of you were lucky it used a connector so you could easily unplug the battery to replace it. I suspect that in some cases the manufacturer never expected the machine to in use long enough to need to replace the CMOS battery so they simply soldered it on. It seem that at some point, PC motherboards seem to have coalesced on using button cell batteries in holder that allows for easy replacement of the battery when needed. Soldered on batteries are a particular problem for retro computer collectors as the batteries will eventually leak and damage the motherboard due to the battery acid. That’s why if you have an old computer with a CMOS battery that has yet to leak and your storing the computer away, or it’s the battery is simply old then you should remove the battery to be safe. If it’s soldered on then desolder it and replace it with a battery holder that allows you remove the battery when storing the computer away and to make it easier on yourself when replacing later on. Always replace very old batteries on old computers with new one regardless since you never know when they will start to leak and they will leak at some point, mark my words. .
If you have an old Apple Macintosh you might run into a tricky battery problem. It's been a long time since I handled one of these so I can't remember the model. Thing is the machines power button was on the keyboard. But it wasn't powered by standby power like they usually are on a PC, but instead there were a lithium cell inside the keyboard. If this ran dry then you couldn't turn on the computer. I had a customer bring in one of these when it refused to start. We didn't work on Apples machines but he asked us to take a look. My colleague opened up the keyboard to see if the switch might be broken and he was pretty surprised when he found a lithium cell inside. When it measured in at about one volt he replaced it and suddenly the machine worked again.
Another fun thing was that the motherboard in this Mac was manufactured by LG-Electronics, or if it was still called Goldstar. Actually that might just have been the PCB in the keyboard that was made by Goldstar. It's been so long I can't remember. I do however know that a portable Mac (PowerBook 100 or possibly 140 - 180) was manufactured for Apple by Acer.
4:03 Yes, Roman, we feel your pain, now more than ever. 😂
Funny story… back in 1994 I was driving from Chicago to Minnesota, during a blizzard, during spring break. The cell phone my parents gave me for emergencies rang. The emergency? The cmos battery died on our home computer and I was the tech support. My dad thought it was my fault, argued with me until he heard me yell “Oh Shit!” Three times. I crashed into a side rail because of the snow. Fun times. No one was hurt except the turning light on the front right of my ‘81 Toyota Tercel.
I love Riley & James sooo much, you guys bring value to LTT
I’m building my first pc and my motherboard arrives today. I love these videos
Back in the 90s my dad use to have a "security password" so I couldnt play when he wasnt home, and I discover that removing that will remove the password, but the time too, but I figerit out and chage it back.
I was like 8
I once had a coworker forget their BIOS password, it was amazing how easy it is to remove that battery, wait half a day, and log back into a computer bypassing the password. Physical security is real 😢
Half a day? Do you mean minute?
@@itsTyrion I veered on the side of caution waiting for all the capacitive charge to dissipate, it was my first and only time doing that so I didn't know what to expect 😂
Or...you..could just....short the battery holder's contacts and be done with it.
"clear_cmos" jumpers also exist.
The clip of Linus pouring liquid nitrogen is everywhere.
Great video as always! The more we know: Answering questions I’ve always wondered but rarely asked.
I can tell you first hand what happens when the battery goes bad. Random BSODs and weird BIOS behavior like it doesn't save settings yet doesn't tell you so. Very hard to debug, but easy to solve.
I had the same issue with random BSODs and start up issues. Had some spare batteries so I swapped them out. Boom, no more blue screen and start up issues.
128 bytes isn't always 128 characters. I would add ASCII before characters because a Unicode character may not be one byte. Hence why low level languages handling strings are scary sometimes as you can incorrectly address the string a way it wasn't meant to be read.
String handling is really tricky , rust language has 8 char and string types for instance. There was no reason in low lowel to account for encoding non ascii char hence it might look weird. Languages like C# has 2 bytes allocated for character.
I wish there was an standard guide line.
@@sps014 and the real kicker is, even those 2-byte characters are not enough to encode all Unicode characters, and the language has exceptions when you attempt to sever a surrogate pair (which encodes one character in 4 bytes).
There is a way to encode all Unicode characters in 4-byte characters called UTF32, but that takes so much memory just so you can cover for infrequent characters.
@@TheMixedupstuff yeah you are right 2 bytes is not enough to account for all characters, thanks for info
I used to work with a BIOS engineer. He programmed the BIOS in hexadecimal codes.
Well wen talking about the NVRAM used for the setup you can feel pretty certain there's no Unicode chars stored in it. Instead a lot of settings are stored as single bits instead of wasting memory by using an entire byte...
Now if you are talking about UEFI, which isn't really BIOS but it's successor, then I guess there may be some Unicode characters used in the configuration.
NTP is *DEFINITELY* used on home PCs. What do you think is happening under the hood when Windows synchronizes the clock with "internet time"
Plus. Many servers do still keep an internal clock and a battery, but NTP time is preferred, with local time being a backup source.
We were actually talking about how Windows client machines typically don't use the UEFI network stack to connect to an NTP server at boot time, rather than the time service inside Windows. Our apologies if that was not clear.
Thank you for watching!
@@techquickie awesome! I gotcha now. Although it bears noting that the OS clock will often update the hardware clock also, if enabled (usually by default)
@@StrokeMahEgo Secure Boot certificates have valid date range. So if you are using a UEFI OS with Secure Boot enabled and the CMOS date gets corrupted or reset to a default outside of that certificates range then the BIOS wont let you boot the OS and if you cant boot the OS then the OS can't fix the time.
Heh, quite a fair amount of motherboards these days, like ASUS hide the CMOS battery behind fancy panels, making it a nightmare to remove if there's a reason to do so.
Only For Fans Over 18 Years Old↷ᶜˡⁱᶜᵏˡⁱⁿᵏ👇 (◍•ᴗ•◍)
KOOTONANOKSAI.XYZ/Anggeline?AV-jK✰
𝕤𝕖𝕟𝕤𝕚𝕥𝕚𝕧𝕖 𝕔𝕠𝕟𝕥𝕖𝕟𝕥 💦
Megan: "Hotter"
Hopi: "Sweeter"
Joonie: "Cooler"
Yoongi: "Butter"
Asi con toy y sus mañas no se la lease que escriba bien mamon hay nomas pa ra reirse un rato y no estar triste y estresado.por la vida dura que se vive hoy .
Köz karaş: ''Taŋ kaldım''
Erinder: ''Sezimdüü''
Jılmayuu: ''Tattuuraak''
Dene: ''Muzdak''
Jizn, kak krasivaya melodiya, tolko pesni pereputalis.
Aç köz arstan
Bul ukmuştuuday ısık kün bolçu, jana arstan abdan açka bolgon.
Uyunan çıgıp, tigi jer-jerdi izdedi. Al kiçinekey koyondu gana taba algan. Al bir az oylonboy koyondu karmadı. ''Bul koyon menin kursagımdı toyguza albayt'' dep oylodu arstan.
Arstan koyondu öltüröyün dep jatkanda, bir kiyik tigi tarapka çurkadı. Arstan aç köz bolup kaldı. Kiçine koyondu emes, çoŋ kiyikti jegen jakşı dep oylodu.#垃圾
The good ones tend to have cmos clear buttons, But otherwise you can just jump the cmos connections on the board with a metal object if you can't get to the battery :)
That subtle flip so Riley points the right way is pretty funny.
You should remove the battery from your computer if you're thinking on storing it for a long time, and if you bought an old computer that has it, you should check it up immediately.
After many years, they tend to leak badly all over your PCB.
Never had any of them leak though. Only had to replace them after they've run empty in storage.
I think I'm ready for the A+ certification now.
I actually wrote my current RAM timings into the XMP profile, that way if I ever have to replace the battery or even the whole motherboard, I can just enable XMP and it's back to normal
And I can fit an entire sandwich in my mouth.
We opened up the PS4 and we saw this installed in the Motherboard. ✌️ Had to replace one on my Truck Keys Remote Locker / Unlocker and the Motherboard. 😯
Great video , one computer that comes to mind that does not have a RTC is the raspberry pi. The ironic thing is that I have a pi4 running Ubuntu as a local ntp server.
Thankfully my CMOS didn't clear when I removed my CMOS battery but an easy way to know it's time to replace it is when your PC starts losing time (especially if you have it set to not fetch time from the internet). You'll first notice this when a program breaks or a browser page or log in something doesn't want to work. After 7yrs of service, mine was due.
It really sucks when your CMOS battery dies and you can’t boot into your PC anymore, but aren’t sure why. Took me hours to realize that the CMOS battery was dead, and that the issue was in the BIOS settings.
I have a vintage motherboard in storage that uses jumpers for settings instead of a BIOS menu system. It's got jumpers all over the motherboard with labels for each. Funky stuff.
Complimentary : expressing a compliment; praising or approving.
Complementary: combining in such a way as to enhance or emphasize the qualities of each other or another.
Complementary metal-oxide-semiconductor (note the hyphens) is the correct form. BTW the Metal-Oxide-Semiconductor describes the 3 basic layers of the construction (originally Aluminium now polysilicon, Silicon dioxide , doped silicon), not some mythical Semiconductor that is a metal oxide.
The CR2032 in my copy of Chrono Trigger is 25 years old. And it's held the save data all these years. My best guess is it's easier for such a battery to simply hold data in place than it is for such a battery to run a clock for upwards of a decade.
Only For Fans Over 18 Years Old↷ᶜˡⁱᶜᵏˡⁱⁿᵏ👇 (◍•ᴗ•◍)
KOOTONANOKSAI.XYZ/Anggeline?AV-jK✰
𝕤𝕖𝕟𝕤𝕚𝕥𝕚𝕧𝕖 𝕔𝕠𝕟𝕥𝕖𝕟𝕥 💦
Megan: "Hotter"
Hopi: "Sweeter"
Joonie: "Cooler"
Yoongi: "Butter"
Asi con toy y sus mañas no se la lease que escriba bien mamon hay nomas pa ra reirse un rato y no estar triste y estresado.por la vida dura que se vive hoy .
Köz karaş: ''Taŋ kaldım''
Erinder: ''Sezimdüü''
Jılmayuu: ''Tattuuraak''
Dene: ''Muzdak''
Jizn, kak krasivaya melodiya, tolko pesni pereputalis.
Aç köz arstan
Bul ukmuştuuday ısık kün bolçu, jana arstan abdan açka bolgon.
Uyunan çıgıp, tigi jer-jerdi izdedi. Al kiçinekey koyondu gana taba algan. Al bir az oylonboy koyondu karmadı. ''Bul koyon menin kursagımdı toyguza albayt'' dep oylodu arstan.
Arstan koyondu öltüröyün dep jatkanda, bir kiyik tigi tarapka çurkadı. Arstan aç köz bolup kaldı. Kiçine koyondu emes, çoŋ kiyikti jegen jakşı dep oylodu.#垃圾
Yes, this is the reason Pokemon Gold and Silver's saves only last 2 to 3 years. The battery inside the cartridge doesn't only keep saves, it also runs the internal clock that ticks even when your cartridge isn't plugging in. So every couple years it dies and when it dies there goes the save. (as you can imagine it's a smaller battery than the one on a motherboard).
@@PINKEDASHPT so I've heard. Makes me wonder how long the batteries for my Raspberry Pi RTCs are gonna last, but those are at least easily replaceable.
My motherboard (ASRock B550 Phantom Gaming 4) actually has two pins on it called a "CMOS Jumper." Basically I just touch them with a flathead screwdriver, and that resets my BIOS. I had to use it while I was initially building my computer because it wasn't booting correctly. Which is good, because I found the CMOS battery on the board pretty difficult to remove.
I did the same thing with the same motherboard when my PC wouldn't boot following an unstable overclock.
I study all these stuff. You are on point and correct.
I already know about the CMOS Battery, but I like these videos anyways!!!
Only For Fans Over 18 Years Old↷ᶜˡⁱᶜᵏˡⁱⁿᵏ👇 (◍•ᴗ•◍)
KOOTONANOKSAI.XYZ/Anggeline?AV-jK✰
𝕤𝕖𝕟𝕤𝕚𝕥𝕚𝕧𝕖 𝕔𝕠𝕟𝕥𝕖𝕟𝕥 💦
Megan: "Hotter"
Hopi: "Sweeter"
Joonie: "Cooler"
Yoongi: "Butter"
Asi con toy y sus mañas no se la lease que escriba bien mamon hay nomas pa ra reirse un rato y no estar triste y estresado.por la vida dura que se vive hoy .
Köz karaş: ''Taŋ kaldım''
Erinder: ''Sezimdüü''
Jılmayuu: ''Tattuuraak''
Dene: ''Muzdak''
Jizn, kak krasivaya melodiya, tolko pesni pereputalis.
Aç köz arstan
Bul ukmuştuuday ısık kün bolçu, jana arstan abdan açka bolgon.
Uyunan çıgıp, tigi jer-jerdi izdedi. Al kiçinekey koyondu gana taba algan. Al bir az oylonboy koyondu karmadı. ''Bul koyon menin kursagımdı toyguza albayt'' dep oylodu arstan.
Arstan koyondu öltüröyün dep jatkanda, bir kiyik tigi tarapka çurkadı. Arstan aç köz bolup kaldı. Kiçine koyondu emes, çoŋ kiyikti jegen jakşı dep oylodu.#垃圾
These are great vids for students just getting started with their computer hardware career!
My Computer Tech class literally just covered this. I might as well start treating this channel as part of my course LOL
I came across several Microsoft Surface devices that lost their clocks when they were powered off. They were old, so I suspected that their clock batteries had gone bad. We couldn't replace them, though.
They use the built in battery. Mobile devices besides laptops with externally removable batteries don't have CMOS batteries. If a surface is not keeping time, it would be another issue, like the RT clock itself.
@@alexfrick3801 Oh, that's even less repairable.
@@wecsam Yeah. I would check to make sure its not a software issue though, because having an RT clock go out with the rest of the logic board still working is rare, though not unheard of.
@@alexfrick3801 I only saw it twice in the four years that I worked there, so it was indeed pretty rare.
@@wecsam The piezoelectric oscillators that are used to make the base clock which the core clock is a multiplier of are usually high quality, but the ones used for the clock are often off the shelf, sometimes literally. I have a couple of dell dimensions and all of them use a little metallic cylinder with two transverse leads that are exactly the same ones used in cheap clocks. They got a little quartz crystal in them, and are often not made to the same quality as motherboard oscillators since they are going in to cheap mass produced clocks. The ones used for the motherboard base clock are usually packaged in a small dual in line package and usually use germanium rather than quartz as the piezoelectric element, and are of higher quality. Gigabyte boards and asus boards particularly have been known to use high quality oscillators for the RT clocks that were manufactured specifically for their motherboards, the same way as the ones for the base clock. While it's rare for any oscillator to fail on a board, the clock ones are more likely to do so if they are this cheaper kind. And unlike the motherboard oscillator it wont make the whole thing fail, just the RTC function.
I'm amazed about the timing of this video.
Only For Fans Over 18 Years Old↷ᶜˡⁱᶜᵏˡⁱⁿᵏ👇 (◍•ᴗ•◍)
KOOTONANOKSAI.XYZ/Anggeline?AV-jK✰
𝕤𝕖𝕟𝕤𝕚𝕥𝕚𝕧𝕖 𝕔𝕠𝕟𝕥𝕖𝕟𝕥 💦
Megan: "Hotter"
Hopi: "Sweeter"
Joonie: "Cooler"
Yoongi: "Butter"
Asi con toy y sus mañas no se la lease que escriba bien mamon hay nomas pa ra reirse un rato y no estar triste y estresado.por la vida dura que se vive hoy .
Köz karaş: ''Taŋ kaldım''
Erinder: ''Sezimdüü''
Jılmayuu: ''Tattuuraak''
Dene: ''Muzdak''
Jizn, kak krasivaya melodiya, tolko pesni pereputalis.
Aç köz arstan
Bul ukmuştuuday ısık kün bolçu, jana arstan abdan açka bolgon.
Uyunan çıgıp, tigi jer-jerdi izdedi. Al kiçinekey koyondu gana taba algan. Al bir az oylonboy koyondu karmadı. ''Bul koyon menin kursagımdı toyguza albayt'' dep oylodu arstan.
Arstan koyondu öltüröyün dep jatkanda, bir kiyik tigi tarapka çurkadı. Arstan aç köz bolup kaldı. Kiçine koyondu emes, çoŋ kiyikti jegen jakşı dep oylodu.#垃圾
While you imply they are not needed, servers in datacenters do have the same CR2032 coin cell battery on board. So do the network switches and chassis managers. You will spot them in hardware teardowns on ServeTheHome, and in Open Compute server documentation.
I'm curious if anyone knows of exceptions - a server (not RPi or SBC) with no CR2032.
I remember Amstrad PC1640 and PC 1520 used to use AA batteries on the top of the base under the monitor stand for the CMOS
Oohh. So that’s why I found batteries in my old Nintendo cartridges. Good save.
I think one thing is really good about the video but first I want to thank MSI for the sponsorship
Basically, its a CMOS battery, which is needed for storing BIOS settings on motherboards. These batteries are not needed for your PC anymore for BIOS settings anymore, *BUT* they are needed for time settings on home computers.
They didn’t always use a coin cell battery. Older computers used whatever they pleased, from +6V batteries, to AA, to the dreaded Dallas RTC chip with a built in battery that was often soldered in (requiring a replacement or DREMELING THE HOUSING TO ADD A COIN CELL BATTERY)
BEGONE SPAMMER
Had to change this battery about a year ago because in windows the time would not show correctly. Wish this video had been out then, would have saved me some time!
Only For Fans Over 18 Years Old↷ᶜˡⁱᶜᵏˡⁱⁿᵏ👇 (◍•ᴗ•◍)
KOOTONANOKSAI.XYZ/Anggeline?AV-jK✰
𝕤𝕖𝕟𝕤𝕚𝕥𝕚𝕧𝕖 𝕔𝕠𝕟𝕥𝕖𝕟𝕥 💦
Megan: "Hotter"
Hopi: "Sweeter"
Joonie: "Cooler"
Yoongi: "Butter"
Asi con toy y sus mañas no se la lease que escriba bien mamon hay nomas pa ra reirse un rato y no estar triste y estresado.por la vida dura que se vive hoy .
Köz karaş: ''Taŋ kaldım''
Erinder: ''Sezimdüü''
Jılmayuu: ''Tattuuraak''
Dene: ''Muzdak''
Jizn, kak krasivaya melodiya, tolko pesni pereputalis.
Aç köz arstan
Bul ukmuştuuday ısık kün bolçu, jana arstan abdan açka bolgon.
Uyunan çıgıp, tigi jer-jerdi izdedi. Al kiçinekey koyondu gana taba algan. Al bir az oylonboy koyondu karmadı. ''Bul koyon menin kursagımdı toyguza albayt'' dep oylodu arstan.
Arstan koyondu öltüröyün dep jatkanda, bir kiyik tigi tarapka çurkadı. Arstan aç köz bolup kaldı. Kiçine koyondu emes, çoŋ kiyikti jegen jakşı dep oylodu.#垃圾
last month i had to replace two bios batteries in our working stations from 2012. apparently the bios battery also controls (gives current/voltage to a) chip which is used for coordinating usb devices and the boot order. this results in an error that the pc trys to boot from any usb device, be it a mouse, stick, or keyboard. -.-
i know about this cmos batt but i never changed my cmos batt in my 2011 lenovo t420 still works and keeps time 100% correct
Hey zack, we appreciate you
I put my old CMOS Battery on my wrist watch and it works. Saves me a dime for a new battery
It’s funny because I already know why, but I just like to watch anyways
I had to replace that battery once when I bought a PC from Goodwill
One time I changed the graphics output in my bios to the integrated gpu in my dell precision.
..but it had an intel xeon.
If that little battery diddnt exist the system would have been bricked forever.
Dell nowadays use cheaper battery for the RTC. In the 2010-2015 models the battery is 10 years plus life, but since 2016 it runs out juice just after 4-5 years.
That's the best channel anyway... that's how I found out about the whole LTT anyway. 🙂
This has to be the most common knowledge things in the computer space.
If I remember correctly my old gateway computer used to tell me when the battery needed replacement.
I wish that removing the battery to clear cmos (bios settings) was an option that you could disable if you dont want that feature and want it to retain the settings.
CMOS battery .... take it out and watch what happens lol 😆
Another interesting thing is that you can turn on a PSU without a motherboard, you just have to jump two pins on the 24pin connector to "trick" it.
Lmao, that clip of Roman and Linus at the end
After a power outage my PC would not turn on (power button did nothing), yet the MOBO leds worked fine / power supply did not smell burnt. I was thinking of getting a new PSU since I had no idea what the issue was. Turns out that, on my ROG STRIX Z370-G mobo, if the cmos battery dies... the power button will simply not do anything. Glad I tried swapping the battery, before I got a new PSU.
Joke's on you motherboard; I keep track of my RAM timings with a spreadsheet.
For SBCs like the Raspberry Pi there’s even RTCs that use a super capacitor for power.
old PCs used to use NiCd rechargeables - if you've got one somewhere cut out the battery as it will leak!
I know the "magic spell" joke probably wasn't a Dresden files reference
But im gonna choose to believe that it was
Oh... so maybe this is why an old laptop our family owned would always have the wrong date and time whenever we turned it on: because the battery was probably dead.
The statement at 2:52 is wrong. Windows and Linux use NTP to keep accurate time. It's not just servers that use NTP. Desktops and laptops use it too. Also, servers still have CMOS batteries (at least the HPE ones I've worked with for many years do). The BIOS in servers does not use NTP. Most of the time, you just allow the host OS (Windows Server, Linux, VMware ESXi, etc.) to set the time. The OS will adjust the RTC (real-time clock) -- the circuit that needs power from the CMOS battery to keep incrementing the time while the computer is off. NTP is necessary no matter what because the RTC is not accurate. The time kept by the RTC will drift over time, so computers need to query NTP servers because the NTP servers get their time from atomic clocks. Atomic clocks are far more accurate.
As an Electronics Engineer who works with digital semiconductor design. When someone starts talking to me about CMOS it throws me off every time that they’re just talking about a nvrm for bios. Like, most of the board is CMOS. lol
I'm curious how many of those tops Riley owns. They look so comfy.
it actually makes sence.If you watched the video at the first 2 min of the video uploading,you could finish it and comment
I already knew the answer but still I watched the video and learned about the CMOS chip.
LOL you guys needed to collaborate with AMI for this? :D
yeh, mines just got pins you touch with a paperclip I don't think any board makes you remove the battery anymore to reset it. but yeh, that works too.
what in the... i literally was just looking at the CMOS battery of my motherboard, and thinking "why does it need that?" and few hours later, got this video recommended.
If that battery dies it's a pain in the ass especially in a custom built PC. All the BIOS settings will be reset as soon as the power is turned off.
Luckily Asus BIOS allows you to save profiles which are non-volatile but it's still troublesome to load it every single time it boots.
Make sure to buy the battery from a store which have the latest manufacturer item as I bought this battery from a radom electronic store the battery had around 2.8v and my computer need 3.3v and that was frustrating to fix
I have one that's over ten years old and it clears all my BIOS settings to default when the power is turned off. Guess I should change it.
So question. When replacing the cmos battery, what is important? I know the size but how do I know what one to use?
Thanks for the video!
The computers I have had over decades of which I typically keep for over 12 years have never had a battery issue. I am confused though about - if a computer is either left on 24/7 or mostly left in Sleep mode 99% of the time, does the regular power supply take over from the battery thus greatly extending it's life? I always wondered as to why a battery can last 12 years or more. Thanks
Same honestly
@@cookiesrawesomee No answer yet??
Idea: The history behind the difference between Windows/Mac keyboard layouts
it’s surprising that not many people know about it
Recetnly the battery died and i was really wondering why my PC stop working lol. It was a 10-13 year old PC/battery sooo yeah. If people still use an old PC and it suddenly stop working or booting, it could be that. Don't panic like i did ;p
Had to replace the battery from my 2017 x370 MSI board a few days ago.
Seeing an ad with Linus in it while watching a tech quickie video. Lol