Fixing an ezOutlet with inappropriate components.
ฝัง
- เผยแพร่เมื่อ 4 มิ.ย. 2019
- This unit was sent to me by Matt Ludlow. It's an Internet connected socket that can either be turned on and off remotely with an app, programmed to cycle for routine rebooting of routers or to actually monitor whether the router has maintained a connection to the Internet and reset everything plugged in if it has lost the connection. The latter function is worth its weight in gold to avoid late night service calls.
The reported fault was that the unit would energise the relay and load when powered, but would then drop out after a second or two and start again. That's often a common sign that a power supply is failing to deliver enough current. The circuitry runs until it tries to energise the relay, which then pulls the voltage down low and drops out or resets the circuitry.
In this case I was able to diagnose and repair the unit, but the original components were very small and the module is a close fit in the case. I'll order new components for it.
The reference to using an external USB supply is one of those emergency fixes that can get you out of a hole when something fails and you can't get an immediate replacement.
To elaborate on why a failing capacitor can cause intermittent crashing of an older piece of equipment, especially if it runs hot, the capacitors characteristics can change giving it the appearance of being a much lower value. The fault is hidden until the increasingly rough DC finally gets low enough to be below the regulation level of the voltage regulator and the voltage dips in the circuitry supply can cause progressively more crash prone or glitchy performance. Capacitors are cheap enough to routinely change out to rule them out as the possible cause of a problem.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
www.bigclive.com/coffee.htm
This also keeps the channel independent of TH-cam's advertising algorithms allowing it to be a bit more dangerous and naughty. - วิทยาศาสตร์และเทคโนโลยี
That brand of cap failed in a cheap flame lamp that had run less than 20 hours. Thank you for making electronics, engineering, and circuitry into a wonderfully digestible affair.
This video just proved why Bigclive is my favourite electronics youtuber. I learnt a lot in this short 15 mins. Thank you.
I really like it when you go off track for a bit. The hint about monitor picture tearing at the corner was really useful... as was the quick way of measuring ripple with a meter set to AC. These are the tit-bits that you usually only pick-up with experience. Great video and interesting as always.
Word.
I come here for the subject matter of the video, but I learn the most from the "off topic" stuff.
Kinda like a fox at the chicken pen, just sniffing about the fencing for a gap...
I was suprised to read this, still am.
We genuinely learned that in school, like 3 years ago.
I agree. When he started talking about old industrial stuff and measuring ripple I was very happy that he went off on a tangent. I work at an old steel mill and this really is good info
"tit-bits"
Was going to say the same thing - Clive's tangents are one of the things that keep me watching. Sometimes educational, sometimes humorous, never a waste of time.
That sort of 'blip blip blip blip' of the LEDs was a dead giveaway the power supply was faulty. It's a common failure mode on switch mode supplies. I go straight to the caps if I see that, and it solves the issue almost every time. I've seen it on everything from TVs to wall warts. Nice explanation of ESR.
Doesn't it happen to LED light drivers all the time too? That rapid flickering looks very familiar!
I really appreciate everything that was included in this video; a very down to earth description of AC ripple, great explanation of the power supply and contextual relevant tangents. It what makes this channel so relevant and valuable.
The 2000 hrs is when run at their max rated temperature. Usually 85degC.
It wouldn't surprise me if it ran that hot or hotter if it has some logic and processing chips in there along with the switching supply. Although these are chinesium ones so 2000 hours at any load is probably optimistic. Takes me back to the early 2000's motherboards with all these caps looking like some sort of fungal growth after awhile.
The ripple current heats it up internally, and inside such an enclosure there is likely a much higher temperature than room temperature
@@mysock351C That was my initial introduction into electronics - the capacitor plague of the late 90s onwards. I had a relatively new and relatively expensive (at least for me) motherboard that failed due to bad caps. So I bought a soldering iron and ordered some good quality Japanese caps and fixed it. I've been slowly learning more since then - mainly by watching Clive (as I don't do well learning from 'courses' or the like).
Also running at their maximum rated ripple current, which generates further internal heat
every 10degC below rated roughly doubles the lifespan. So if it's rated at 85degC you can run it at say 45degC (not unreasonable for a well designed supply) it'll last ~3.65years - enough for the warranty period on a lot of devices! This one failed because a combination of either:
-Too hot
-Too much ripple
-Crap quality and wouldn't even meet its mediocre rating
Big Clive, the master troubleshooter
Got a dead smart plug for a router
He cobbled that wreck
With caps, out of spec
Now The Net's back on Matt's computer
HAAAAAAA! 3am and I got a kick out of this one that woke everyone in the house!
They failed to see the humor like I did....
@@IFailFirst That is a perfect example of "You Had to be There"!! :-) Well written, Doug!
out of spec. i remember when i fixed my tv, the only capacitors i could get locally were 450v i needed 35v but hey couple wires, double sided tape and the tv worked
The capacitor that failed is next to the diode. Those are almost always the first thing that fails in flyback topology power supplies since they are directly exposed to the raw ripple current. When I repair PSUs, I add a 10uF MLCC across the electrolytic's leads on the back of the board when possible to spare the electrolytics the worst of switching transients and take some of the flyback edge off.
Not sure why I never thought of that, but using the multi meter on AC to measure ripple is genius! Thanks for the tip!
It only works on modern meters with certain AC measuring designs. Traditional meters just switch in a rectifier for AC mode.
The capacitor ratings are for the worst case scenario. for ex: a cap rated at 5k hours at 105c and some ripple current will lose some percentage of it’s ESR and ESL capabilities if abused to the max it shouldn’t fail. Nichicon FP caps rated 12k hours at 105c used on some ATX motherboards will last almost forever because they aren’t pushed a lot
Perhaps those "unusually small" capacitors are less common for a reason.
The reason is that good high quality low esr caps are physically larger and they used the cheapest crappiest smallest ones they could find.
@@simontay4851 correect 10 million for a bowl of nuddelsoup
Had the same issues with small caps in a mixer PSU I recapped a few months back, really hard to find physically suitable replacements with good enough specs. In the end I had to upsize 2 of them as it was "impossible" to get the right ones.
@@petaks01 Same here, the puffed up Chinese ones were all really small and the usual suppliers didn't sell them since all the "good" capacitor manufacturers don't make them.
@@wasserman63 knewdiddle*
At long last, BC managed to get “humping”s into his commentary...and without laughing or missing a beat! Quality.
First he was talking about rooting, then humping. Got something on his mind perhaps?
@@davidwoodbridge862 I think you're right. There's a lot of humping in this video...
It was close... you could hear the smirk...
Very common phenomenon, even in expensive gear. I fixed my £1000 digital mixing desk this way. The trouble is, power supplies are considered commodities and don't receive the same design attention as other circuitry. Also, I found it not as easy searching for "low ESR", instead I consulted the rated ripple current.
Great informative video on ESR caps and how they're different to normal rated caps, thanks for the explanation 🙂 seems the manufacturer skimped on those capacitors due to size they could fit in the enclosure.
Had the same thing in the supply/ballast of a Chinese fluorescent work light (these tubes that are barely larger than the 8 W fluorescent inside). Ended up recycling the whole thing because I couldn't be arsed to find replacements for those super-small electrolytics. The older ones simply used 5 metres of resistive flex (rather than normal copper wire) as a ballast resistor. Only in the late 90s or maybe 2000s they got more complex.
Hey Clive, let me help you with the pronunciation of router. In Australia, rooting is seen as act of procreation. So when you say router as rooter, we Aussies giggle like school girls.
But then “humping” and “riding the humps” made my day.
@8:50 the hours are rated at the maximum temperature of the cap, typically 85 or 105 degrees C
There's a saying that every degree below max temperature doubles the life span.
I was going to say the same thing - as well as something similar to what Ennar said.
I've been told that a 10 degree (peak) drop potentially increases the life by 10x, a 20 degree drop increases it by 100x and a 30 degree drop by 1,000x. However I don't know the truth of that.
@Andrew Ballard Thanks Andrew.
Not just temperature, but also maximum voltage, ripple, and frequency....operating below any of those absolute maximum limits will significantly extend the lifetime of a capacitor....unless the capacitor was made in China, in which case all bets are off...it might last 20 years or 20 seconds regardless of operating conditions.
@@ethanpoole3443 In fact, ripple and lifetime (for a given max temperature and ESR) are interlinked, which means you can trade off one for the other, enabling almost arbitrary specsmanship. Shorter nominal life = this cap gets hotter at given temperature and ripple current. That certainly is one way of boosting your ripple current spec.
Thanks heaps for the ramble Clive, very interesting stuff. Especially about SMPs and the need for low-ESR caps.
I got 3 minutes into this and, when you were saying about if it was a capacitive dropper when the relay kicked in the voltage would drop and I said to myself "then the relay would 'chatter' at 2x mains frequency surely?" Then I had a real "D'oh" moment. I had a set of two RF remotely controlled mains switches and one of them did just that, went into spams when I turned it on and blew the fuses in my amplifier connected to it. I kept it for a couple years in my "NFG" box of things that I might get around to fixing but threw most of the stuff out a short time ago. I figured that my electronics knowledge hadn't got to the level where I could fix most of it by now then there was no need to keep it.
However I still have the other RF remote switch on a shelf so I opened that and, sure enough the power supply (for the three ICs, relay and a couple LEDs) is a capacitive dropper run by an X2 cap rated at 0.22uF / 275V. I bet that's all that had failed in the other one dammit! I've been slowly learning electronics, mainly by watching this channel and, while trouble-shooting and fixing a SMPs would have been maybe a bit much for me, I could have fixed that thing after all. The pair of switched mains units and remote cost me quite a bit too and I haven't been game to use the 'good' one since the other failed.
If the X2 dropper cap has failed it will read as a lower capacitance than stated.
In my younger days, I was a coin-op arcade video game and pinball machine tech. I've replaced a lot of those 470µF 6.3V electrolytic caps (most frequently in the power supplies) tell ya what. But not every bad cap was "pooched out" (showing signs of elevated internal pressure) -- some of them looked perfectly normal even under magnification. But *every* pooched-out cap was indeed bloody frickin bad.
Wonderful tidbit on using your DMM on the AC scale to measure DC ripple!
I'm almost 55 and I've never heard that one before!
Thank you Clive!!! :-)
5:16 “Humps Per Second” - Now here’s a man who has mastered his bit of reality!
Back in the early 80's, I was a TV cable technician. A common problem we had with line amplifiers was caused by failing capacitors in the amp's power supplies. Because we have 60 cycle power in the US and the TV frame rate is 29.97 FPS, (just shy of 30 FPS) the resulting interference pattern was a horizontal line that would slowly work itself from the bottom to the top of the picture. Because we were a small company most of our testing equipment was old and the only way we could find which amplifier was causing this issue was to haul around a small battery powered TV set.
I've just bought one for those solder suckers and it's brilliant. It's extremely well built and miles better than the usual cheaper all plastic ones you get.
The logical design of this would be to take the low voltage supply from the router PSU, direct to the relay and to an output socket / lead that would supply the router, then tap off the low voltage to supply it's own logic through a voltage regulator. Thus it would have no high voltage inside it at all and probably need far less rigourous approval regimes.
I have no idea what your on about when you go all eleccy gubbins but i find listening n watching you take these apart fascinating
I get lost, too. I am hoping one day it "clicks" and I understand it all!
I guess all I can do is keep watching and hope for the best.
The rest is fun too, though! "Let's Spudger this; Is this going to break?; Let's hook this up to mains and will it go "bang"?; I'll try not to touch that as it is Live; this is a really clever design!".
I think the super low service life ratings in electrolytic capacitors apply to the rated temperature. They will last a lot longer if the temperature stays lower, for which reason it's really important to 1) use low esr caps where there's high ripple and 2) design the equipment so that the caps stay well below their rated max temperature.
There are actually a few factors here: Typically, the "lifespan" of a capacitor is the number of hours it is expected to be able to function:
a) When operating at its maximum rated temperature
b) When charged to its maximum rated voltage
c) Before it goes out of spec in some way (not necessarily outright failure)
This is part of the reason why people often use caps rated for higher voltage than actually needed, because operating them at a smaller percentage of their rated voltage can extend their lifespan significantly (as will keeping them cooler, as you mentioned).
*However,* even when it's beyond its lifespan (accounting for voltage and temperature), that still doesn't mean it will just fail either (in fact, that's still pretty unlikely for most caps, even at that point). Usually what that actually means is just that the manufacturer can't guarantee it will still have its full capacity (its capacitance may have dropped to less than the tolerance of +/- (typically) 5% or 10% of its nominal value that the datasheet promises). But even that is still just a "maybe", it could be that it's still fine, the manufacturer just can't reliably know for sure that it will be. And even if it has lost some capacitance, it can still potentially work just fine, but you will get more ripple, etc, in your circuit. Therefore, in many circuits you can also extend the useful lifespan of the capacitor by simply using a somewhat larger one than you technically need, so that it can lose a lot more of its original capacitance before it actually really matters to anything.
Of course the manufacturer/supplier would have told you it was non-repairable and offered to sell you a replacement.
When you said inappropriate components, I seriously expected this to go bang.
@TacticalMoonstone I was actually thinking of another power supply that Clive "repaired"
When he said inappropriate components I thought for sure he was going to try and one up that. I think the video is titled "power supply explodes twice" or something like that.
The advert I got for this video was a man that says you can bring any dead battery back to 100%
I got that ad too... seems like some shady stuff, but I guess youtube doesn't care if the snake oil man pays them -__-
I was told by both Bt and Plusnet keep turning a router on and off disables it from the network and it has to be reset by them, so you could be shooting yourself in the foot buying this device.Thanks for the lesson on power supplies very interesting.
I had an Ondigital box, which I bought cheap as OnDigital went bankrupt. But was relaunched as Freeview, and the box worked with Freeview, just some of the menus did not work right but all the channels worked fine. Anyway a few years later the box became unreliable, looked at getting a new one but was a few hundred pounds for a recording Freeview box, so did some research and fixed it. Turned out it was the power supply as the caps where blown. So went to Maplins and bought everything I needed, as you can see still into electronics now as I'm watching this channel.
Big Clive never goes in a wrong direction, just an interesting diversion!👍
I bought a faulty LCD monitor off eBay a few months back for £2, when it arrived it was apparent that it had been taken apart and didn’t even have any screws in it. Straight away I saw 2 caps on the power supply were blown/bulging so I found some the same (on an old but working sky box power supply), soldered then on and it works perfectly. Put it back together with some screws I had knocking about and she’s as good as new(ish)!
👍🏼
Very interesting, especially the part on the capacitors. I understand now why the secondary ones suffer much more than the one on the primary even if the average voltage is lower.
Great video and awesome insight. Re-capping is a fairly good practice when the replacement of the device is cost prohibitive. I actually recapped some Dell motherboards that had the fake Nichicon E-lytics, because we needed the PC's faster than we could replace them. The fun was unexplainable!
Always learning from you, those are the exact caps I had to drive up to city for, was fixing an old charger for an 18 volt power supply charger I couldn't believe how simple it was transformer then 4 diodes and a cap 4700 35 volts. I soldered it but never tested it yet. I bought a truck and the kansas rain started up then the flood now its drying up now I just got replace the trans then maybe I can get back to my electronics stuff. I needed a break from automobile stuff. Cheers sir BigClive have a good 1
You are brilliant and I second the "like" of when you go off track - so many clever hints and tips. Could you one day take a look at an old audio amp and cure the humming. Would love to see you explain the bits and bobs and give more tips on something more complex.
Big like for the correct pronunciation of "router".
rooter
Yeah!
back on the farm as a young lad, the crt tv would start to round over and shack at around 4pm for two hours. I check the voltage and it would drop down to 90 volt, I'm in Canada where the voltage is 110 to 120 for outlets and light, 220 to 240 for big stuff like pumps, stove and heat. at my new home the voltage is 127 volt, if it get to 130 volt then you are to call the power company. that 254 volt for for the big stuff
A ROW-ter is what you use for woodwork. A ROO-ter is what you use for the internet
It is if you're English. I believe our American friends use their words differently.
Their - belonging to them, not they're - they are. Listening to English and American youtubers of both woodwork and interweb I have noticed a definite difference in how they pronounce the words.
Our American friends use the words belonging to them differently - therefore their.
Anyone else want to adjudicate this debate?
Dave, I know so much better than joining this debate but figured what the hell... I have to agree with you, there certainly is ours and theirs. English pronunciation is called “Received Pronunciation” or RP and American Pronunciation is called “General American Pronunciation” or GENAM. Look it up if you don’t believe me. Why would anyone feel the need to dispute something so mundane though is my question...
I’m am an American but I feel the need to add that the very best dictionaries are written in the U.K. and focus on RP. There are many American dictionaries that go into depth about the differences between the two but honestly, these differences are explained much more in American dictionaries than those written in the U.K.. Also because RP is an “Elite” language, many people associate it with high status and intelligence, but sometimes, as I’d dare say is the case here, with arrogance and unfriendliness...
Oh, by the way, Donald Trump, the American Dipshit President, is currently a guest in your wonderful country. Would you folks be so kind as to keep that stupid son of a bitch there with you and not let him return to the good ole US? I would really be much appreciated!
Many happy regards and much respect,
Buddy
You are certainly welcome to your opinion. Sad that you can be so angry about something like this...
Thanks to my limited electronics knowledge and solder skills from fixing things and bit of Big Clive Inspiration. I fixed my own VoIP adapter (HT-502) which had become very nosy. All I did was replace all the cheap electrolytic caps with name brand ones I picked up from a local surplus electronics supply. Total Cost: $3.50 (owned all soldering supplies.) And I have voip adapter that will probably not go bad unlike the last two. One thing that was interesting was some of the new decent name brand caps where bigger even though being the same specs. (HMM?)
Top tip for identifying duff DC power supplies. Cheers!
11:28 I liked that direction 👍
(The tid bits of info you’d only get from pro’s are great)
8:55 Well, usually, at least in datasheets, the lifetime of electrolytics is spec'd *at full ripple current AND at their rated temperature* (85/105C). The rule of thumb then is that the lifetime doubles for every 10C lower than their rated temperature. 2000h 85C = 4000h @ 75C = 8000h @ 65C etc.
I thought it was funny 😄 that you explained the word “banjaxed” 😆 (me taking that word for granted as I’m in the U.K. & then realising folks in other countries might not understand the reference) 🤗
I had two TP-Link WAPs that were quite good and they both failed fairly close together and I initially thought a power surge had done them in. Opened them up to find the common chinesium type _round top_ electrolytic capacitors. The most expensive cost was the bloody shipping but they both returned to the land of the transmitting for a parts cost of less than AUD$1.50. Nice fix and they will both find a good home(s).
I love all your tangential information
A router finds a route to the internet the same way a 'rooter' finds a 'root' to the internet.
My goto for replacing old electrolytics in electronics are generally Panasonic FR's - low-ESR, decent quality and available in loads of sizes, even smaller ones (they're not the cheapest though). If I recall correctly Würth also make low-ESR compact designs. Sure, they're not Japanese (like Chemicon, Rubycon or Sanyo), but they're at least decent - especially compared to many of the Taiwanese caps.
Shame there's no such thing as a perfect cap, if you're going small in size, you're generally compromising on something else. (Mind out of the gutter!) Be it cost, quality and/or capacitance/voltage.
Great video as always 👍
Can we all appreciate the guy who removed the security screws, those things suck!
Another useful video Big Clive! Thanks.
My old PC used to crash randomly and blue screen or just do weird things in general until I got fed up with it and stripped it down to clean. Looking carefully at the motherboard I noticed 2 clusters of 4 caps near the CPU, they had bumpy tops so I ordered a load of the same type/values and replaced all the electrolytic caps on the motherboard and it worked perfectly after (and still is many years later). Don't be afraid to replace the caps on a motherboard, just be aware of where they come out on the track side and the polarity, don't linger the soldering iron too long on the tracks and be careful of bridging tracks. There are some wiggly tracks near the CPU pins which are for timing the data lines and the caps are close to them. Just take your time, take it slow and careful and give it a go :D
This video explained my broken psu I spent a few weeks on before I ended up cooking it :(
If you are having internet slowdown call Router-Rooter
Root is a subterranean plant support structure.
There's no better way to start your day than Big Clive videos, a bowl of nuggs, and enough caffeine to kill a horse.
You had me at “inappropriate”! ❤️
Going off in a “random direction “ can be very informative!
Great video clive
Love those "Off Label" mods .. .. ..
does Matt want it back after the right sized caps are placed ?
I've used a similar device in the past from another OEM (Aviosys) to remotely power-cycle one of my home servers in case of a complete hang. It was not cheap (IIRC, the single outlet version was about 150 EUR), but it really helped me out many times until I got the server to run stable.
There are versions of these devices with several individually controllable outlets as well. These things are essentially little computers controlling one or more relays.
@9:24 Electrolytic capacitor hour ratings are specified for maximum rated temperature (usually 85 or 105 celsius). Since most capacitors run at much lower temperatures than their rating, they last much longer.
I thought you were going to finish by saying "I'm Scott Manley... Fly Safe" you two could be brothers :-)
One hairy chin, one non-hairy crown. What a combo.
9:25 the lifespan provided by the manufacturer is specified at the maximum rated operating temperature (85°C, 105°C, or even 125°C, depending on the capacitor.)
As you lower the ambient temperature, you effectively multiply the cap's lifespan. If I'm not mistaken, for each 10°C drop its lifespan is potentially doubled.
The capacitor MTBF/hours rating was typically based upon operation of the capacitor at its absolute maximums of temperature, frequency, ripple, and voltage. Reducing any of those factors to well below the absolute maximum values will significantly extend the MTBF...which is why well engineered devices are usually pretty conservative in terms of reducing ripple, peak voltage, and operating voltage so you get a greatly increased MTBF. Also, older electronics tended to be more tolerant of ripple as well, which also means that they tend to tolerate more degradation of the capacitor before they cease to operate. If you download a major brand name in aluminum electrolytic capacitors they will often have some guidelines for estimating capacitor life when operating at less than the absolute maximum ratings.
Clive, if I'm recalling what I learned exploring all the different Cap ratings Mouser lists that MTBF on the cap is for its time to fail at (above? percentage of?) the specified temperature.
So 2000 hours of operation during peak temperature plus (if I recall) a much longer duration under normal stress.
Couldn't see if anyone noted that; no search in this interface!
It really frustrates me that consumer-grade routers/modems/Internet connections are so routinely unreliable that products like this exist and people "rebooting the router" is such a common thing to happen or to hear about. I really don't think it has to be that way... :(
Since mid-2013 when I moved into this house and became responsible for our Internet connection (at my previous house, my then-housemate had that job) I'm fairly sure that I've only ONCE had to reboot a router or modem to restore service.
We have two VDSL2/FTTC 80/20Mbps lines here, each connected with an ECI B-Focus modem ( kitz.co.uk/routers/openreach-modems.htm#openreach_modem ) of the type supplied by BT Openreach during VDSL installs in the early 2010s (although only one of mine was supplied by BT; I bought the second from eBay to ensure that both lines were the same and because that ECI modem is/was well-regarded).
While the ECI modems are probably partly responsible for the high reliability of our connectivity, I think that the primary responsibility lies with our MikroTik hEX, aka RB750Gr3 ( mikrotik.com/product/RB750Gr3 ), which is admittedly not a very consumer-friendly device for configuration, requiring a fair amount of networking knowledge to configure (they have a demo system you can play with here: demo.mt.lv/ ). But it's very stable hardware and software, and not even expensive - the RB750Gr3 retails for less than £60: linitx.com/product/14919
That doesn't include a modem or a Wi-Fi access point, but a lot of more technically-minded people prefer to have those as separate devices anyway. Modems should ideally be right next to the point where the telephone/coax-cable line enters the property, as extending a telephone line BEFORE the modem will usually drastically reduce the attained Internet throughput speeds, and Wi-Fi access points should be positioned with respect to the layout of the building, the construction materials used, where Wi-Fi coverage will be most needed, etc. - and you may even need several access points to achieve good coverage in a building that's large, has brick-built internal walls, or has heavy interference from other devices or from neighbours. Not only is it unlikely that the modem(s) and Wi-Fi access point(s) will be best-positioned in the same place, but there's also no reason for the router itself to be anywhere close to either of those. In fact if, for example, you have a cluster of Ethernet-connected devices in one part of the building (either desktop PCs, games consoles, network storage devices, etc.), you may want to have the router nearer those - or maybe just an Ethernet switch for those devices, with a cable running to the router somewhere else entirely, would make sense!
In my case the modems are by the front door, with Ethernet cables running two floors up, through the stairwell, into my "networking closet" which houses the router and the core 24-port switch. Then the main Wi-Fi AP is also in the stairwell, so there's a cable running back to that.
With my ISP's router, that thing would be utterly pointless. The ethernet side works just fine, it's the wifi that starts making a mess after about a month, so I have to reboot it. I could probably automate that with a programmable outlet, but eh. Too expensive.
Next up, you will find yourself pullin fibre and getting ready for 100G internal network and redundant routers :D
My router has an uptime of several months and my cable modem even longer. With that reliability, I'd never invest in a gadget like this to watch over it. The chance of a failure is just too low. Besides, the router routes everything on my home lan and rebooting it willy-nilly is going to irritate multiple devices that are talking to each other rather than the internet. I'd get blasted with lost connection messages.
That's the one of the main reasons I've switched to using a home server for routing and UniFi APs for WiFi. A little tricky to set up but you only need to do it once and your set up will probably run for months or even years without any issues. I only need to reboot my server for software (and occasionally - hardware) upgrades.
I had a cheap SMPS which failed due to the output diode (a heat-sink mounted TO-220 package) coming loose from the heat sink and heating up until it went temporarily short, which blew out the output filter capacitors. The primary control electronics had a current-limiting feature, so the diode actually cooled back down and stopped being shorted, but the caps were still toast. I didn't think it was worth fixing, as I only paid $9 for it and it was already several years old, so I installed some non-low ESR "JWCO" caps ("JWCO" makes both low-ESR and non-low ESR varieties) that I had on the bench to see what would happen. It not only started working again, but has been working still for the last month, with a lot of very hard service in high-temperature conditions. The output ripple is minimal, as well.
As I understand it, an electrolytic capacitor's lifetime rating is based on conditions of its own maximum electrical and temperature ratings. To make a capacitor last far beyond rated life, one simply "over-rates" components; runs them at well below rated maximums. For instance if it's to be run at 85C and 10 volts, use a 105C/16V cap -- or better.
Clive, i've come across the problem with caps several times before.I just replace them with metal encapsulated SMD ones. Simply remove the rubber foot from the bottom of the SMD cap and bend the legs slightly in order for them to fit into the holes on board. Maybe a touch of heatshrink over the top. Of course it helps if you have SMD one's in first place in the correct values I suppose
The 2000h number translates to something like "after 2000h at 105c ambient temperature, the capacitor's will be within 30% of its specifications" (or some percentage high enough) as in it will degrade significant enough to be outside specs but will still work. Also, with electrolytic capacitors, a basic "formula" says that lifetime rating doubles with every 10 degrees Celsius , so if the temperature inside the box peaks at 95c , then capacitor is rated for 4000 hours, if below 85c you have 8000 hours and so on.
For polymer capacitors, formula is changed a bit, a simplified version would be L = Lorig x 10^ [(Tm-Ta)/20] ... so a 2000h polymer capacitor running at 70c average would be rated for L = 2000 x 10^(70-30)/20 = 2000 x 10^2 = 200.000 hours.
You could get some 270-330uF 10-16v polymer capacitors and replace the electrolytics, it will work.
Hi Clive, watched countless number of your videos and thoroughly enjoy your stuff! Question... How do we send you an electronic something that's broken so you can take it apart, find out how it works and why it failed? Thanks
"Wrong direction". Love it.
Dammit I thought I was a genius coming up with this.
Capacitors are super reliable. Cheap SMPSs often use less capacitance than needed, forcing them to run hot from the ripple current.
Your rooter finds a root to the internet while my router finds a route to the internet, I think I'd rather find the root to the internet!
For the estimated life of a capacitor at a lower working temperature, every 10c below the max temp you multiply by 2. So a capacitor with 2000h at 85c if it works at 45c will have 32k hours estimated life, about 3.5 years (perfect for warranty..).
As for the capacitor replacement you could probably use a 6.3v as the psu out is 5v. Usually they round up the voltage value of the cap if there is a headroom, in this case about 25%
The capacitor closest to the transformer would see far higher ripple currents than the capacitor after the inductor. Also when they dry out from a leak, the ESR increases and they get even hotter and the process runs off much like thermal runaway. On a side note the capacitance usually goes up more when they dry out but they become less effective at filtering due to the internal resistance increase.
TH-cam auto captioning is convinced you are talking about "crack pastors". I just found that amusing enough to share :P
THANKS for the extreme zoom!
You're the best!
Excellent tutorial on capacitors.
Had exactly the same with a Perrin and Rowe instant hot water tap.
The PSU uses a resistive dropper with a 100uF cap across the bridge, driving a relay via an electronic thermostat. Problem was the 100uF was adjacent to the dropper resistor and the heat dried the cap out, the unit appeared to power on, but as soon as the relay energised it turned off again.
Fix, replace the cap and mount it away from the dropper resistor. Just a badly laid out circuit board. I've let them know my thoughts.
The life rated for a capacitor is the life of the capacitor at the maximum rated temperature for which the capacitance of the capacitor does not drop below a specified amount. Generally running a capacitor at 10 degree lower doubles the life time. Note this almost means that if more capacitance that needed is used capacitors may be out of spec but still work due to the over design.
I rather wonder if the failed capacitor was simply labelled for a higher voltage somehow. Not uncommon with some dodgy manufacturers, unfortunately
OoO0oO, inappropriate components. Best kind of components.
You should see them with a few drinks on them.
Those low cap life ratings are at full voltage at maximum operating temperature. if you run them at lower temperatures, the will last a lot longer. same goes with lower voltage.
No wonder my CCTV HDD recorder stiffs out so often! I'm forever re-capping the blessed thing, so much so that I keep a bag of about a hundred 1600uf 10V (105 deg.C) caps on hand just for that purpose.
Off topic, a bit, but I really do love it when Clive says "I'll just get rid of that...." followed by a 'pat-a-rub-thud' in the background. I always get a bit of laugh out it, wondering what on Earth Clive's workshop floor must look like.
This seems excessive even for a device that runs 24/7. Unless your caps are of dubious quality, I'd guess it runs rather hot and may appreciate a mod for better ventilation. (That was pretty much the thing to do for Topfield PVRs back in the day unless you wanted to be able to fry eggs on them. Most common things to fail: PSUs and harddrives, no surprise.) Clearly, a circuit that's taxing on caps is not going to help either. Might be a case for some solid caps (OS-CONs or whatnot), or some _creative stashing_ of additional caps in parallel (twist leads and use leads of adequate diameter to keep ESR and ESL low).
Clive i think it was when they were run at their max rated temp.
Eg 2,000hr @ 85°C
As I have seen the same ones rated 20,000hr & 35°C
Many manufacturers have an equation to calculate expected lifespan based on their nominal ratings vs operating environment. Every 10C below rated temperature doubles life expectancy. A 2000h 85C-rated capacitor can be expected to last ~64k hours at 35C. Some manufacturers' lifetime estimation formulas also include terms for ripple current and DC voltage. Basically, the further below the capacitors' rated specs the capacitor operates, the longer its lifespan and those are pretty significant multipliers. In the case of ripple current, the relationship is usually (i_rated / i_RMS)^p where p is anywhere between 1.3 and 2.5 depending on manufacturer and capacitor family, anywhere from almost linear to more than square.
@@teardowndan5364 I am no expert I just remember seeing things like this on my motherboard spec sheet
Ahhhhh. Nothing better after a long day than a cold IPA and a Big Clive Video
I wonder if there are any funky security exploits on the networking side...
Capacitor life de-rating is something all electronics degree courses should cover but frequently don't. Many consumer electronics companies have been caught out.
Nice, thanks for sharing 👍😀
10:58 I used to work in an electronics service company, about 12 years ago. I remember there was a certain Samsung STB model that had its PSU fail a lot. It was a ripple problem and was corrected by replacing the larger cap plus soldering a small some nanofarade cap across it.
Large cap for buffering, and tiny cap for EMI suppression?
Correct. I googled around a bit and it was the Samsung DTB-P850Z which had the most problems. I believe some of its sister models also used the same PSU but that was the model we repaired the most.
I learn so much from you, how's the TT going btw?
It seems to be going well despite weather issues.
Hi! I'm currently making myself an order for recapping some stuff (monitor PSU and an ATX PSU), very good explanation about why low ESR caps are needed.
I was wondering, what kind of values is considered low ESR?
For the 470 µF / 10 V spec needed here:
Panasonic FR/FM (low ESR): 8x11.5 mm, 56 mOhm, 3000h @ 950 mA @ 105°C
Panasonic FC (standard / lowish ESR): 8x11.5 mm, 117 mOhm, 2000h @ 555 mA @ 105°C
Jamicon TK (standard ESR): 6.3x11 mm, tan(δ)= 0.20 @120 Hz, 2000h @ 260 mA (120 Hz) @ 105°C (ripple current @ 100 kHz: +20%)
It is obvious that the last one must have a substantially larger ESR than the FC, considering that Pd = ESR * I_ripple², though I'd guess it is also less heat-resistant in general.
On a side note, in general lower ESR in Al electrolytics tends to be detrimental to leakage current and, as a consequence, long-term stability in lightly loaded scenarios, as they are more likely to fail short. So in practice you have to find a good compromise. A traditional audio amplifier is likely to be the wrong place for ultralow ESR caps. You might even find some _low-leakage_ parts in one, which are on the other end of the ESR spectrum altogether.
Nichicon RLB (low leakage): 12.5x20 mm (!), tan(δ)= 0.17 @120 Hz (ripple current = 0.8 of 100 kHz value), 1000h @ 570 mA @ 105°C
I had to go up to 63 V to find a 470 µF Jamicon TK the same size:
Jamicon TK (standard ESR, 63 V): 12.5x20 mm, tan(δ)= 0.10 @120 Hz, 2000h @ 580 mA (120 Hz) @ 105°C (ripple current @ 100 kHz: +25%)
In general, I'd assume a quality "normally low ESR" would do fine to replace monitor PSU caps, especially dodgy ones. If you can fit the next bigger voltage rating, that's usually beneficial, too. On the secondary side of an ATX PSU, I'd pull up the original caps' datasheet and find something at least equivalent. If they are from some reputable manufacturer, they may have been undersized or from a faulty series (some of these exist - usually researchable on badcaps.net), otherwise good-quality equivalents may again be all that's needed.
The lifespan is coupled to the temperature. They usually have a graph but for simple specification they just give life expectancy at its rated temperature. Better quality caps will be 135deg C but these are expensive.Another way to improve things is to use a higher voltage spec. but that will result in a larger capacitor and also higher price. 2000hrs at 85deg C would probably equate to 20000hrs at 40deg C.So keep your power supplies cool and they should last a long time.
Cheap multimeters just add a diode and more resistance to the input on "AC." If in doubt, make sure a battery measures 0V both ways before using it to measure ripple.
As suggested below the lifetime rating is at maximum everything, temp, voltage, and ripple. Drop these by a few percent and expected lifetime multiplies..to the extent if you are careful in your electrolytic choice they will last almost forever. (forever being 30+ years).
Those smaller sized electrolytic caps seem to fail more often than the larger ones of the same rating. I guess that they are somewhat optimistically rated. Looks like the swollen unit was closest to the diode so may have seen some heating.
When I first saw that unit I thought it was a very old mains unit. In the olden days electrical items were black. Now they’re white or cream.
Capacitors is what power supplies crave, they have ELECTROLYTES
brawndo!
2000 hours at 85C, rule of thumb is double the lifespan every 10C below max they run, so 64000 hours at 35C = over 7 years operation even in a "warm" device. Even longer if its kept cool away from high dissipation components and in air conditioning or such. Plus some were rated for 105C or even 125C rather than 85C, so can last for decades of continuous operation if kept cool.