Tip & How-To about General Computers & Internet

Computer Crashes and Electrolytic Capacitors

Electrolytic Capacitors are something to keep note of when troubleshooting computers that crash. Symptoms can be: Will not boot, have distorted or no video, randomly shut off or on, distorted or no audio, or just do random and crazy things. Electrolytic capacitors can be found on a lot of electronic circuit boards (motherboards, video cards, sounds cards, power supply boards, network cards, etc). They look like a long cylinder with a stripe down one side indicating the negative polarity lead.

When looking for bad capacitors always check the motherboard first. The motherboard will typically have electrolytic capacitors around the processor. You then want to look at the card directly involved with the failure. If everything still looks good, then it can also be in the power supply. With general symptoms and where to look: Issues with powering on and off (motherboard and power supply), issues with video (motherboard and video card), issues with sound (motherboard and sound card), and etc.

Some general tips on recognizing a bad capacitor is looking at the top and bottom. The top should be flat, so if you see it bulging out, then it's bad. You also want to look the tops and bottoms over for any brownish substance leaking out. This substance is the electrolytic part of the capacitor and it can do damage to circuit boards. It can eat through traces, solder pads, through holes and cause opens that can't be fixed. Any time you see this on a circuit board, look it over very closely for damage after you remove the capacitor and clean the electrolytic off. I just use rubbing alcohol on a Q-Tip to remove electrolytic from a circuit board. Some manufactures use glue, epoxy, or silicon on parts to bond it to the motherboard. Don't confuse glue for a leaky capacitor. That stuff should be hard and not clean off with rubbing alcohol.

Electrolytic capacitors are usually easy to replace using a soldering iron, solder wick, solder, and side cutters. Make sure you put the new capacitor in with the stripe on the same side as the one you took out. If you don't, it could explode. Always wear safety glasses!

For more information about electrolytic capacitors, troubleshooting, getting parts, and replacing them, go to this link: http://www.capacitorlab.com/index.htm

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emachine does not boot both fans are working


Here's a video on how I fixed my emachines boot problem. Almost anything can get in the way of your computer booting. Software, hard drive, RAM, motherboard, processor, etc. Below the video, I attached a link to a tip I made about computer crashes. Computer Crashes and Electrolytic Capacitors

Apr 11, 2014 | eMachines T Computers & Internet

2 Answers

hi, I have a asrock P4vm890 motherboard, the problem is when i go into bios to change the boot sequence to first boot from dvd, the bois freezes on me. what could be the cause.


First of all, Windows would crash.

Leads me to think hardware problem, not software.

Further to suspect the Processor fan, and finned Heatsink underneath; are dirty.

Even more further to wonder about the condition, of the Electrolytic Capacitors on the motherboard.
(They are Radial Aluminum Electrolytic Capacitors, to be more specific)

http://www.capacitorlab.com/visible-failures/index.htm

http://www.youtube.com/watch?v=ngA4k32jLGc

http://www.youtube.com/watch?v=oDGjWOabJ2E

http://www.hardwaresecrets.com/article/616

http://www.hardwaresecrets.com/article/How-to-Identify-Japanese-Electrolytic-Capacitors/595

http://www.youtube.com/watch?v=YCSNWi3UHf4

No?
Then suspect the Power Supply. Try one from another KNOWN to be working computer, (And is Compatible), for a test unit.

For additional questions please post in a Comment.
Regards,
joecoolvette


Dec 28, 2012 | Asrock P4VM890 Motherboard

1 Answer

compaq presario sr1420nx wont boot up keeps turning on and off resetting rapidly how to open computer..when it did turn on was getting unmountable boot volume error had it fixed at geek squad once and 3 months later did it again and i never had it connected to internet after it was fixed


Turning on, and off sounds like bad capacitors on the motherboard.

I don't believe the members of the organization you took it to; have the savvy to repair.
(Frankly I don't think they could pour P out of a boot..................Wait!...............Did I say that out loud?)

This is what it states from Microsoft for 'Unmountable boot volume',

http://support.microsoft.com/kb/555302

The jist is the Harddrive cannot be reached - Bad IDE ribbon cable
The Windows files are corrupted - Use Restoration Disk
BIOS Settings are set wrong.

I'm going to state something different. May be putting my neck out...

Capacitors on the motherboard.
To be specific the ones used on your motherboard are Electrolytic Capacitors.
More specifically; Radial Aluminum Electrolytic Capacitors

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00363478&tmp_task=prodinfoCategory&cc=us&dlc=en&lang=en&lc=en&product=457247#N394

An Electrolytic Capacitor has Electrolytic paste inside.
When the capacitor starts to fail, it's because the paste has developed a gas inside. Hydrogen Gas. The gas expands, and pops the seals of the capacitor open.

So much paste loss, and the capacitor operates at a weakened state.
Too much paste loss, and the capacitor fails.

Capacitors are used as Voltage Regulators, and Filters.
The ones used as Voltage Regulators, are in the Motherboard Voltage Regulator Circuit,

http://www.hardwaresecrets.com/article/616

Part of what the motherboard voltage regulator circuit does; is to regulate voltage for the Processor.
The Processor MUST have a steady, 'clean', supply of voltage; and it MUST be kept within the small tolerance range, for the Processor.

Cannot be too much, or too little; or BIOS will turn the Processor off.

The Processor is the 'Brain' of the computer.
Guess what happens if it turns off, turns on, turns off, etc?

I think what you are seeing.
Cannot access boot files on the harddrive.
No processor.

Suggest;
Computer off, and unplugged from power.
FOLLOW Anti-Static Precautions.

Anti-Static Precautions
Your body carries Static electricity. Static WILL fry out (Short Circuit), the delicate hardware components inside a computer.
Relieve your body of Static BEFORE reaching inside your computer.

Computer ON a table, computer unplugged from power, computer case open;
TOUCH an unpainted surface, of the metal frame of the open computer case.
This action will relieve your body of Static.

IF you leave your computer in the middle of working on it, be SURE to Touch the metal frame again, upon your return.

There are going to be cables (Wires), in the way. You can gently move them aside to look at the capacitors. L@@K close. May need a bright light, and magnification.

Capacitors look good, I'm full of beans?
OK. Onward through the fog.

Replace the IDE ribbon cable going TO the harddrive.

Test the Power Supply, or see if you can borrow a KNOWN to be good, Compatible power supply; from a working computer for a test.

I think capacitors, therefore motherboard replacement.

Not advertising for seller, nor website. Just from a quick search,

http://www.ebay.com/itm/ASUS-P4GV-LA-Micro-ATX-Motherboard-Intel-SL7TS-2-93GHz-CPU/130808856405?rd=1&ssPageName=mem_guide:3&ih=003&category=131511&cmd=ViewItem

MAKE notes, and drawing/s as to where EACH cable plugs into.
The ones I may not be able to help you with, are USB, Front Panel audio, Front Panel Firewire (1394a)
Power cables, data cables to optical drive/harddrive, plus Front Panel header; yes.

For additional questions please post in a Comment.

Regards,
joecoolvette

Nov 28, 2012 | HP Compaq Presario SR1420nx...

1 Answer

my desktop shutdown after several minutes, reboot it again but it shutdown again. reboot again but same thing happen, pc shutdown. what is the problem?


That's like stating my car was going down the road, then suddenly died. What is the problem?

Open the hood, take a look. Maybe it's something obvious.

Same thing with a computer.

1) Computer unplugged from power, open the computer case. See if the Processor fan is dirty, and the computer case fan/s.

If so use a can of compressed air for computers, and clean.

[NOTE*
BEFORE you reach inside your unplugged from power computer, observe Anti-Static Precautions ]

2) See if there are Electrolytic Capacitors on the motherboard.
Bad capacitors for the motherboard voltage regulator circuit, will cause rebooting.

How to identify bad capacitors,

http://www.capacitorlab.com/visible-failures/index.htm

The motherboard Voltage Regulator Circuit,

http://www.hardwaresecrets.com/article/616

Example;

http://www.youtube.com/watch?v=KN6_-8fYHo0

(Starts at 0:04)

3) Power Supply

Weak Voltage power rail. Caused by failing Electrolytic Capacitors.
(Radial Aluminum Electrolytic Capacitors)

Sep 04, 2010 | MSI Computers & Internet

1 Answer

picture is distorted keeps on moving


Good Day,
You have problem with caps on the Hyper Board. This is how to repair it:

MVPU13 Hyper Module Repair (23786198 / 23148017X)
Corrective Action: Remove the MVUP13 Hyper Module from the TV chassis, remove
the top shield and replace all of the 10uf, 16v capacitors using Part Number 24619040 It’s recommended that all of the capacitors identified be replaced. (Note: These capacitors are low impedance surface mounted aluminum electrolytic capacitors. Care).

GOOD luck, big IRISH.
should be taken to avoid damaging the PCB while replacing these capacitors.

Dec 08, 2009 | Toshiba 42H81 42" Rear Projection...

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