What the capacitors are doing on a laptop motherboard
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- เผยแพร่เมื่อ 9 ม.ค. 2025
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Today Sorin grew from Expert to Grand Master Expert in my standards, and I will expain.
I am train as technician in Electronics and Electromecanics... but this video is something that I never encounter before in my training or other people experimented.
I always believe Sorin is very good but today he was moved in "Best Off" category. Today lesson hit me hard...
Not all capacitors are there for the FCC, there are also there to filter noise from nearby components either under certain conditions/places from events produced by the laptop/device itself or noise outside.
This is why it matters some times it matters and others it doesn't.
The noise produced, depending on the intensity can disturb data lines causing data corruption which is where, at principle and if properly implemented in practice as well, filtering capacitors exist and are placed in certain places.
Also, the number of capacitors alone might not be enough to pass an FCC test if a certain capacitor is filtering a very specific frequency spectrum which other capacitors don't matter because they are removed since they might be filtering a very different range spectrum and thus as a result now the laptop/device is emitting a signal in that frequency which is now unattenuated.
Of all the repairs we see though it seems 99% of the failures are the caps Sorin speaks of.
I didn’t hear Sorin stating all capacitors are there for FCC matters.
No capacitor. No short capacitor. No job for technician. Just leave the mainboard like that way Sorin. So i can run my bussiness 😊😊😊😊😊
i somethimes liked SORINS videos before even i watched them because he built a good reputation and respect in my heart with his impressive skill and knowledge. plus he is also a good teacher of life and business. I am very grateful for your delighted heart. may god give you health and happiness. thank you.
Long story short (coming from a hardware designer), its for EMC compliance. CISPR25, IEC 61000, and other friends. Local mitigation improves overall EMC performance. If a board is not compliant, it just doesn't go to production, simple as that.
"Replace your fear with knowledge" - Sorin
Knowledge alone does nothing if it is not practice to become experience and thus when combined with knowledge, wisdom.
My first PC, a mighty 286 I bought in the early 90s, inhibited the AM radio my father used to listen to his favorite news show, so, I was banned from using the PC while he was listening to his radio.
You're right, Sorin. But don't forget to speak about output caps, the ones used to smooth out the inductor output ripple...yes, alright: these are lytics...mostly. Thanks for another excellent video. And regards from Madrid, Spain.
yeah, he forgots to speak about that.
@@homersimpson9257 there was no need as even he replace output caps
Maybe you should try those soldering tweezers for those smd caps etc?
PeaceFromOz.
@@andrewverran3498 indeed, they are extremely comfortable to work with. I use the ones from Weller.
@fichambawelby2632 they look like a no brainer...I night start with a Yihua set..in general I'm pretty happy with the Yihua stuff I have bought.
PeaceFromoz.
Excellent talk about input caps. Another talk about output caps would be good.
Capacitors do more than just helping devices pass FCC. Sometimes they are critical for communication circuits as they can be very noise sensitive. Also, the roles of the capacitors only becomes appearent when the system is under full load. But I do agree with your conclusion that most of the times you are fine without replacement. One important risk of replacement is that you could replace caps with caps with the wrong voltage rating.
I wonder why replace them if value and voltage is unclear, do you want to create problem yourself?
If it would be caps near the driver of an HDMI, ethernet port, wireless circuit, USB port or LVDS screen connector I would replace them. If they are electrolytic caps or high value caps I would replace them too. You'll have estimate the risk of replacement and compare it to the risk with taking them out. @@juliusvalentinas
Hay Thanks , At first i thought this was silly just to prove your point but I seriously learned something important. Keep being they way you are "dodgy", If it works that is what matters... it seems the easyest way for me to learn - love it. .
EEVBlog did the same thing ,but he removed all the input caps if I remember correctly and was no issue with the board after, good work Sorin.
Sorin, I know that, but THANK YOU VERY MUCH, for the first time I've seen someone simplify the reason why so many capacitors are installed. THANK YOU AGAIN TO HEAVEN.🇷🇸❤️🇷🇴
You really know your stuff Sorin. You make understanding Easy.
Ce tare! Nu m-am gândit ca producătorii pun condensatori pentru a trece testul FCC. Multumesc pentru prezentare foarte bine explicat și apreciez foarte mult efortul de a explica.
Grozav, acum înțeleg ce vrei sa zici. Foarte interesant ce am învățat azi, mulțumesc Sorin!
" replace your fear with knowledge " good one sorin
One of the best videos you've done Sorin and great explanation! 🎉
Thanks for sharing your wealth of knowledge and experience.
A super informative post, thanks again, I learned a lot, Franz
I always learn a lot in this channel, it is gold!
hi sorin ,i love your videos i spend the most of my day time whatching your videos thank you for your work
Very interesting analysis. So a fault may resolve simply by removing a bad cap!
Thanks Sorin!
Replacing fear with knowledge is a great deal
Thank you for the very detailed explanation I really appreciate the time you took to fill my knowledge gap.
Now I understand why you aren't replacing capacitors.
The big capacitors are for filtering while the smaller ones are for high frequency bypass. Under heavy computing loads the big capacitors will provide extra current while the smaller ones will prevent ringing. The overshoots at the edges of the pulses are due to insufficient high frequency filtering. On top of that the power rails should have no pulse present if property filtered. They should have clean dc outputs.
No DC line is 100% clean. With a better scope, one can see all kinds of electrical noise.
Sorin, you are the man! Thank you for all your interesting videos with detailed explanations.
Good morning a ot of thanks for simple and grat explanation of capacitors. Now i will be more calm in my amateur repairs. Great job i'm your fan.😊😊😊
Wise Sorin, thank you for sharing your knowledge.
Thank you Sorin, very good explanation.
Amazing explanation. Never knew this. I'm glad I now know it.
Replace your fear with knowledge… thanks Sorin, great video and excellent explanation as always, stay safe
what an excellent explanation and examples, thank you teacher!
Hi Sorin thank you for that great explanation.
This video also contains, useful details in the comments.
Well done 👍
Verry good explanation
Usefully.Thank you Sorin.
Very well explained Sorin. Thank you!
Fantastic explanation of laptop capacitors!
Very nice explanation. Thank you for the video!
I think the video should really be called "Dodgy Sorin Explains Why He Doesn't Replace Capacitors He Removes!"
Fantastic tutorial and great use of your oscilloscope! 😎 This video complements the lesson you did with Diana where you shortened the wires to prove the switching power supply signal got less noise when doing so.
i had asus motherboard before.. with a shorted main power rail caused by a shorted capacitor on cpu vcore input.. i had it removed and was able to power ON the laptop..
but this happens next.. whenever i type any key on the keyboard, the screen flickers.. it does not flicker when i use usb keyboard..
i was about to tell the customer that it either needs a new keyboard or a replacement screen.. but i placed back a working capacitor on cpu vcore input.. the problem with keyboard typing making screen flicker is gone..
i have absolutely ZERO idea what was going on.. but it the end, a replacement capacitor fixed the problem..
Sorin thanks for making this video and explaining about caps in laptops, probably the next time people will stop calling you dodgy :)
Great video Sorin!
At last someone stepped up to stop capacitor enraged crowds from the internet - Thank you!!!
Thank you for the explanation, very usefull
You just took a ton of stress out of my shoulders
Now you can give longer warranty for that asus as it has less likely get shorted capacitors.
Excellent tutorial. I would want to ask that you could demonstrate how to test a RAM with any cadgjet to see if it is in excellent operating order, similar to how we test capacitors.Suppose it's something you recently bought or took off of a PC.(Examining it when it is out of the laptop/PC slot)
Lets see, there is no power "spiking" in the system, which makes you right only so long as there are no voltage or current
spikes in the system. You would be right 99% of the time. Its when a capacitor blows up that makes you and this demo
wrong. The blown capacitor absorbed the power spike and died. What I'm saying in no way takes away your genius when
diagnosing laptop faults. Love your work. Capacitors serve a purpose: they take out the spikes and the ripples much like
coils. And in moments when there is a power deficiency, in some part of the circuit, a capacitor is there to provide a few
extra electrons. Keeps things running smoothly. Analogy: its like smoothing out tension and slack in a chain. Too much
tension and the chain snaps and a capacitor blows up. The system runs cooler with capacitors and stops all sorts of knock
on effects. **Its only if electronics operated at super conductivity that we could do away with capacitors.**
As things are in real life, capacitance forms all over the place in electronic circuits, with sparking results. Capacitors give
these electrons an open space to park. Two parallel tracks on a circuit board .... capacitance. What is a touch screen: its
capacitance. Put a capacitor in place: no more working touch screen. Electrons love capacitors in preference to tracks or
wires. **I've written all this down for my own amusement.**
And one would be enough for that. All these caps he removed in this video are on same 19V rail. As he pointed out in a video there is minimal resistance due large ground and VCC planes in board, having any cap at any position on board between these plates will cover condition you're talking about.
There are people who are amused by pretending to be smart and there are people like Sorin.
@@gorky_vk
One is not enough: because different parts of the board are chewing up different amounts of power. Different parts of the
board are hotter than others ... dah.
Zorin's demo
It doesn't explain why capacitors blow up. The big ones blowing up right next to little ones. Are you paying attention when
blown capacitors are being removed? And they blow up in specific places and not others: it is uneven power in the circuit.
And wires don't have to touch each other for electrons to jump an air cap. Capacitors minimize sparking and arcing, among
other things. And lets not forget TIN CREAP with so many free electrons in circuit boards of bygone days. Coating a circuit
board alone does not solve that problem. Capacitors: the place to be for electrons to play in, jump around in, arc from layer
to layer instead of inside sensitive CPU chips. It is excess electrons that spark and arc. And when you have 8 phases going
into a CPU, each phase irons out its own ripples of current and voltage .... with capacitors. The whole purpose of 8 phases
is more precise control of ripple .... a more constant current .... because of more sensitive CPU's and GPU's. But go ahead,
remover all capacitors and rely on the circuit board's layered capacitance. And when you see a bridge rectifier soldered on a
board, remove those capacitors too. Zorin, does an excellent job of motherboard diagnosis, and teaching electronics as he
goes along with his simplified approach .... dispelled a lot of my ingrained mis-conceptions. This is not one of them.
If a motherboard had all its capacitors removed, the board would in quick time start arcing between layers and become the
victim of tin creep and short circuits. Clouds carry charge: its where lightening discharge comes from. Now imagine clouds
of electrons between circuit board layers and discharging between those layers. **Is that amusing enough!!**
Awesome video and explanation, thanks!
Thank you sir for the explanations
i loved the subject of the video. informative and sample based video .
Great explanation, thanks
Sorin what works is replacing the cap for a new cap of higher capacity.
So for 19v use 22v or above and just get new of same size but highest capacity.
5v use 6,3v.
Also FCC rules are excessive but this is partly to prevent and make sure with no doubt that e devices will not effect electronics on planes trains or other important electrical equipment.
I agree 100% NO CAPICTOR NO DEAD CAPICTOR.
Hi Sorin, any chance you could make an update video about a good choice of linear power supply in UK? I m looking for one and it seems very hard to find one on eBay or Amazon, everything is a switching one :D Oh and is there a video showing a modification to remove the short protection from it? Many thanks greetings from Edinburgh
"no one is going to remove 5 capacitors", meanwhile me using a laptop with exactly 5 capacitors removed
Very good explanation 👏 👌 thank you
An excellent video Sorin, good to see you using the oscilloscope. Any chance of a video for scope beginners? Trying to trace a sound fault on a laptop and a scope would be really handy.
Of course, this is true only for "parallel mode" capacitors, when it used in serial mode you have to replace it (even if you don't know the exact value)
Should change the title to, "Find out how I got rich selling capacitors"
@st_us: Lol and again lol.
Great video
Soriin the legendary CAPterminator :D but I think the output ones should remain in service. Thumbs up
Excellent video as always! Does this apply to power supply capacitors only, meaning that they must have one leg connected to gnd and these are the only ones we would find shorted?
Those capacitors who help maintaining the CORRECT voltage source to the CPU, if they fail, at the time that the CPU pull current to achieve the best performance, the computer shut off.
You forgot to remove the 25V solid caps😅
Try to replace your fear with knowledge. Thank you sir .❤
amazing explanation, thank you.
A bloody load of nonsense is what it he. He is clueless!
then why they are so important?@@d614gakadoug9
Thank you that this video helped me a lot.
Thank you sir
WoW! what a info! Great .
Brilliant explanation 💪🏼
First I do the same. In Notebooks I don't replace the capacitors when there are more than one in the same place, near the controller. The value for filtering capacitors is the bigger that the size admits. Don't forgot stability capacitors need for the switching controller leave one at least. Look at the datasheet and basic apliccation. The risk is that the chip loose the hability to control the output. The 97% of the chips has no problem but some may be.
great explanation!
Now this is a thing that school don't teach us. This is a Propper electronic school.
ESD protection, I blew one laptop capacitor just by touching 😂 You are top man 👍 massive difference in this timeline, time ago engineered to last , these days standards different
نوتیفیکشن سورین بیاد ویدیو باز میشه!
عالی هستی مرد 🤘🏼
داداش منم الان دو ساله فقط بخاطر سورین میام یوتیوب!
we need to share the capacitors and not be greedy and keep all to our self
great half part of the story - waiting for the other half
I always knew one thing: if Sorin says there's no need for replacing the cap, it means there's no need for replacing the cap.
Is it true that the capacitors also help stop mis-timing or false switching on the chips? Any blips / ripples should be cancelled with capacitors present so no false triggers.
yes could be a use for a cap... i build a game controller, i didnt use a cap before, but it didnt register the button press well.. placing a proper cap anything worked great..
I can't believe that he actually didn't put the capacitor back! How can you sleep at night knowing that you have remove só many capacitors in you life.
Hahaha good job, thank you for sharing the knowledge.
Nice. Thank you.
do we have capacitors wich can not be removed from latop motherboard without altering its functionality ?
big capacitors, eletrolytic ones.
I have frequently witnessed you and others elsewhere repair dead laptop circuit boards by soldering in a jumper wire. Nevertheless, I would like to know if it is a good practice to short over or avoid, say, a
1. resistor.
2. Capacitor (CMD)
3. The diode next to the HDMI port.
4 A MOSFET, either elevated or flat.
whwn you cant get the spare.
A week a go I managed to restored one of my dead HP Laptop Pavilion 15 DAR 62 REV A by following one of your tutorials when i used a jump wire/short to bypass a capacitor, a mosfet for the 3.3-volt display, and a diode adjacent to the HDMI socket.
u can only bypass a dead fuse and sometimes a protection mosfet.. nothing else.
now I am scared to join discord 🥴
thank you Sorin to share us with this knowledge
🙏🧡🙋👍😺very instructive, Thanks!
Sorin sir please teach us about output capacitor.
Thanks.. for the info
Robiłem takie testy w laboratorium akredytowanym. Sprzęt i sama komora robi wrażenie. Wpisz sobie komora do badań EMC.
Can you do a video testing a capacitor versus a proper calibrated fuse?
Do u know the difference between wire and capacitor right? I believe u dont :D
multumesc pentru timpu acordat!
Can I remove electrolytic capacities too?
I can't say anything but go in peace and come back to us quickly
Usually i just replace with any value because all of them in Parallel mode so whats the deal.
Why do CE and FCC set a threshold on radiation. It's because of reliability of historic devices with a bad design (not enough capacitors) They receive radiation and have a small chance of malfunctioning. Basically paranoia which is still seen in prohibition of cellphones on planes and in hospitals. Very stupid because devices in hospitals and planes are particularly well designed, with loads of capacitors.... Also the circuit-antennas receive signals from other circuits on itself. Capacitors are indeed better safe than sorry. However, CE and FCC went overboard...
Very interesting video
I wonder why replace them if value and voltage is unclear, do you want to create problem yourself?
I always get backlash from using proper calibrated fuses, people are so ignorant and so quick to speak up.
No capasitor no problem 👍🤣😝
salute master