Replacing Motherboard Capacitors?

cmort666

cmort666

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I just had the second of two of my ECS A780GM-A mother boards [apparently] fail a couple of days ago.

I don't have the money to replace this one, which was my main desktop, since I'd have to buy MB, processor AND memory.

I see a lot of discussion in technical forums regarding cheap capacitors failing, rendering MBs inoperable. I also see a lot of posts about replacing the failed capacitors.

Has anyone done this, and do you think it's worth the effort?

As I said, I can't afford to replace the hardware. Nor do I want to reinstall Windows and all of my apps from scratch (The data should still be good, and I have backups of important stuff.).

I'm going to be looking at the boards tonight to see if I see any damage. If I could fix these boards by replacing the caps, that would bring not just my Windows 7 back, also another good Linux installation that was running on the the board that failed first in a Linux server.

Any suggestions would be appreciated.
 
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Hard to say if this is doable, most circuit boards today are multi layer and most hand held soldering irons will destroy the lands un-soldering and re-soldering. You will also need a solder sucker or at least solder wick. You must also be certain of polarity when replacing capacitors, if you reverse them they will explode. If you haven't done it before the odds are against you.
Most times when caps fail the either leak or bulge. If you don't see any visible damage you might want to consider looking elsewhere for the problem.
 
Comrad is right. Motherboards are delicate these days. Plus, do you even know that it's a capacitor that's bad? I fix electronics for a living and even I don't do multilayer boards.

On the up side, it's already broken. It's not like you're going to ruin a working board. So, you have nothing to lose. The worst that can happen is that it still won't work.
 
Rastoff said:
Comrad is right. Motherboards are delicate these days. Plus, do you even know that it's a capacitor that's bad? I fix electronics for a living and even I don't do multilayer boards.
Click to expand...
I've got two of them in the same condition. I was awake when one died, and smelled burning. I'm pretty sure that's what happened.

I'll be looking at both boards tonight.

Rastoff said:
On the up side, it's already broken. It's not like you're going to ruin a working board. So, you have nothing to lose. The worst that can happen is that it still won't work.
Click to expand...
That's pretty much how I look at it. I'll have less than $10 in parts into both of them. I can't afford to buy a motherboard, processor and memory anyway.
 
Go for it, sir! :)

A few months ago, I replaced the power storage capacitor on the motherboard of our Irrigation System Controller. The cap, which stores power to get you through those annoying, short power outages without losing all the programming, was cheap on eBay, came quickly, and went right in nicely.

The RainBird controller has been "right as rain" ever since, pun intended. :o

A used, replacement controller would have been about $50 eBay, if I could have found one. Saw several that had already sold in that price range during my search, but nothing was available.
 
I have replaced capacitors on several motherboards, a couple power supplies, and even a couple LCD monitors. Mostly with success, not all of it permanent.
As mentioned if you have leaking or bulging caps they are good candidates and you can often find $10-$20 kits for a given motherboard or LCD on line if you have the soldering skills.
At least if we are talking about desktops.
Notebooks are another matter and the caps are generally surface mouth and much more densely packed so requires a much higher level of skills and equipment.
 
On a side note your OS is on the hard drive so all you need is the driver disk for your new MB. You shouldn't lose anything.
 
I got a dead Dell out in the garage. If you were closer I would give it to you. It's got a bad power supply and I have pulled the harddrive. The madra board and processor are ok, I think.
 
I'm not an electronics expert, or even a novice for that matter, my experience is building a few intermediate to advanced electronics kits.

Here is a tutorial from Ramsey electronics that might help if you're new at this.

And since no one else has mentioned it yet, you might want to try to find out what is frying them before you start replacing them, unless you buy them by the dozen. The soldering section in the above tutorial might give you some clues to look for.
 
The larger electrolytic capacitors on motherboards and in the power supplies are prone to failure over time, even if you have good quality components to start with.

These capacitors usually use thru-hole leads, which are reasonably easy to remove from the board without damaging the board, but just be sure to use a lower-wattage iron rather than a solder gun, which would apply way too much heat.

These capacitors typically fail either shorted, which is often easy to spot, or "open", in which case finding the bad one can be difficult without removing it from the board and checking it with a capacitance meter. They'll often also fail in groups, so you may want to change out the whole set. (Remember that these usually are "polarized", with a plus and minus side like a battery. DON'T put one in backward! :eek: )

The real trick is that when a capacitor fails, it may take out other components as well, or have been taken out by another failed component. In power supply circuits, often there is a MOV/ transient absorber or diodes that failed first. If you have a surge absorbing power strip, it also has these MOVs, usually disc-shaped components. These also only work for so long, and WILL eventually fail with repeated surges. If they fail shorted, you'll know it. If they fail open, the only way you're likely to know is if the surge strip has an alarm circuit that checks for this.
 
I primarily work on vintage electronics but, I also do laptops and some computer devices. Be aware that a lot is surface mount and, as others have noted, multi-layer. I don't change out parts randomly or in bulk due to the possibility of doing more damage. If you have test gear, you can try and troublshoot the system.

I go through power supplies mostly which is why my C: drive image is not hardware connected and neither are my backups. Anyway, check the power supply under load for proper voltages. Then, the power supply circuitry on the motherboard. After that, most components are usually pretty stable.

Oh, and if you're lucky, you can put your drive into a new box and try and boot. It may ask you to install a bunch of drivers and reverify the software but, frequently, they will boot in a new box once the drivers get loaded.

Good luck.
 
LVSteve said:
Look for capacitors that have become domed on the top when they should be flat.
Click to expand...
Yes, this could be an indicator of a bad cap, but only a test will show for sure. Putting an ohmmeter on a cap should show a short increasing to an open, but it takes some experience to really understand what you're looking at. Some multimeters have a capacitance function.

And, the advice to discover what's causing them to go bad is good. Capacitors do age and fail, but it's more than likely due to some problem external to the cap.
 
Yes, I've done some of this sort of thing.
Before you even think about it, I recomend that you dig up any unused pci card and practice removing and replacing a few parts.
don't dive into that mobo till you can do it without lifting any traces off the board.
Once the copper traces peel due to taking too long.... your boned
 
My advise is to toss the MB and buy a new one on the auction site for $50. Buy heatsink paste (artic cool, i believe) and reuse the memory and processor. You are going to spend hours looking for the failed component and then search for a replacement.

You may get lucky if you search at a computer repair shop. They will often have used boards for a discount from customers who upgrade their system. Scrounge around. You'll be surprised at what you'll find at Goodwill, university auctions or friends.
 
Rastoff said:
Yes, this could be an indicator of a bad cap, but only a test will show for sure. Putting an ohmmeter on a cap should show a short increasing to an open, but it takes some experience to really understand what you're looking at. Some multimeters have a capacitance function.

And, the advice to discover what's causing them to go bad is good. Capacitors do age and fail, but it's more than likely due to some problem external to the cap.
Click to expand...

ALWAYS TRUE --- IN *THE OLD DAYS*
A company in Taiwan manufactured a bunch (a tremendous bunch) of caps and sold them for much less than *real* caps go for.
Manufactures jumped on these things and they're in most electronics made from 2000 to 2010 (!).

I just re-capped my dead monitor - I think the set was $12 on eBay.
Here's an article explaining The Capacitor Plague
 
jjcobra said:
On a side note your OS is on the hard drive so all you need is the driver disk for your new MB. You shouldn't lose anything.
Click to expand...
I've seen where they can do some ugly things when trying to recognize new motherboards, but it's pretty much hit or miss. Sometimes it's relatively painless, other times it's a nightmare.

Hopefully, I'll get the capacitors swapped out and it won't be an issue.
 
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