Bulging capacitor

[RegEdit]

Is it sometimes "normal" for a computer to have a slightly bulging capacitor? This computer has absolutely no signs of a failing motherboard (ex- shutting down, freezing up, etc) and passes all tests. The MB just has this bulging cap staring at me. I've seen failing motherboards that had capacitors that didn't bulge as much as this one.

 

[katz]

I always replace bulging caps. They will become a problem soon, so why wait. It is easy money and a reliable repair when done correctly.

 

[RegEdit]

I always replace bulging caps.

I once tried removing a bad cap. I held the soldering iron against the solder point and the thing would not loosen. Perhaps it wasn't hot enough? Do they use a different solder on MB's?

 

[stro]

They almost never do, you need to add fresh solder to get the new solder to mix with the old and then use a solder sucker to get it out. Also sometime you need to make contact with your solder tip higher up to get more heat, being careful to not rest the tip over and area on the board with other leads or contacts.

 

[inlinetech]

Never normal to have a bulging cap. Your iron might be underpowered. Can you tell us equipment you are using?

 

[RegEdit]

The iron I was using belonged to a friend. I was using a really narrow tip. Not sure if I tried using the higher up part of the tip. As I was heating it up I kept trying to wiggle the thing out. Not luck. I also have a cheap little Weller iron. Not sure if that would work any better.

The bulging cap is on a customer's machine. The cap is only slightly bulging, but I can feel the bulge. On MB's that have failed I haven't even been able to actually feel the bulge, let alone barely see it. This one I can see. It looks perhaps something like this pic...
(also how long might a computer last with a cap like this if luck was on someone's side? 5 years?)

 

[dgiles79]

I have had computers with several bulging caps and several leaking caps, and they have worked fine. Eventually they all start having problems though. I would replace it.

I just had to replace all the caps on a Dell GX270, and I had one that was a real challenge to get out. Ended up getting the hot air on it, and it came out pretty easy. If you dont have a hot air station, just make sure you have an iron that can get hot enough, and add some solder to it like mentioned earlier.

 

[RegEdit]

Eventually they all start having problems though

What kind of time frame might one expect? I know this customer is gonna want to cut corners. I just want to give them a likely time frame for failure.

I'm curious if Geek Squad replaces caps or do they just replace the whole MB?

How much risk is there in replacing these caps? As in risk of damaging the board?
Hot air station like this one?

 

[compnet]

What kind of time frame might one expect? I know this customer is gonna want to cut corners. I just want to give them a likely time frame for failure.

In my opinion its impossible to say. Like dgiles I've seen working boards with completely blown caps leaking electrolytes everywhere. The only honest answer to give them is it could die anywhere between tomorrow and 20 years, but there is definitely a part failing.

My local geek squad tries to get customers to replace boards for DC jacks. I wouldn't expect them to do any other board level repair.

 

[RegEdit]

How much risk is there in replacing these caps, such as risk of damaging the board?
Do those hot air station work better/easier/hotter for jobs like this?

 

[B Trevathan]

A "normal" capacitor will not be bulging at all. Most of the time they blow out the vent on top, but sometimes they blow out the bottom and sometimes even out the sides.

If the capacitor on the motherboard looks like the one in your picture then it needs replacing. Get a new one and make sure the capacitance (micro farads) match, you can go with a little higher voltage but you should try to match the voltage on the bad capacitor.

A 30 watt solder iron and a small desoldering pump or desoldering braid should work fine to remove the old solder. The old solder should melt within a couple of seconds. Too much heat can damage the board.

If you can't find the parts locally, go to www.mouser.com they are great IMO.


A little quick searching found these links you may find helpful:

Video of pictures of bad capacitors
http://www.youtube.com/watch?v=oDGjWOabJ2E

How to Solder : Removing Solder
http://www.youtube.com/watch?v=j-_pnc-Qqm8

How To Desolder
http://www.aaroncake.net/electronics/desolder.htm

How To Solder - Soldering Tutorial
http://www.aaroncake.net/electronics/solder.htm

The Basic De-soldering Guide Photo Gallery
http://www.epemag.wimborne.co.uk/desolderpix.htm

The Basic Electronics Soldering & Desoldering Guide
http://www.epemag.wimborne.co.uk/solderfaq.htm#pump
Note: DO NOT use "Cold Soldering"

Bad Caps
http://badcaps.net/

 

[Big Jim]

As above have said it would be anyones guess how long the board would last with damaged cap.

I have an ATI X1900 gfx card here that has 6/7 caps on it and 5 of those have "popped" they dont have the marks in the top like the one pictured so when they went the tops have actually burst open like a cartoon explosion and my god do they make a noise when they do pop.

Anyway as well as this I left the fan wire caught in the fan one day so it wasn't spinning, the car overheated to the point the fan actually melted and had to be scrapped. this card still works now, although it is in the spare parts/testing bin now.

 

[TLE]

How much risk is there in replacing these caps, such as risk of damaging the board?
Do those hot air station work better/easier/hotter for jobs like this?

There is a small amount of risk like any job you undertake, but aslong as you get a suitable replacement Cap, and take you time, you should have any issues. If your unsure pull out an old working motherboard and have a go. You can then test that it still works.

I wouldn't use hot air to remove a Cap, you will end up heating up other components. These really need to be done with a soldering iron, and as suggested, add plenty of flux, and some fresh solder to the tip of the soldering iron to create a bridge between the new solder and the old solder.

 

[rudger]

I always advise customers if I see bulging caps on a motherboard even when I am not looking for a hardware issue. but I have seen all kinds of problems due to faulty Capacitors.

Last month I had a customers computer where the onboard network card started appearing as an unknown device and would not accept the correct driver so I fitted a PCI NIC and the computer is working fine.

Others have been failure to boot right through to poor stability, I posted a question about replacing capacitors last year on a shuttle PC the outcome from the customer was to replace the PC, the customer gave me the old case and Motherboard so I decided to replace the Caps and see how long it would last. I set the machine up as a new Test machine for myself and so far it has been up and running 24/7 for about 3 months without a problem,

The link to the discussion is http://www.technibble.com/forums/showthread.php?t=31343

 

[RegEdit]

so I decided to replace the Caps

Did you replace just the bulging caps or all of 'em?

 

[rudger]

from what I remember I replaced all the caps around the CPU I Left the smaller caps around the PCI Slots and Sata ports. only cost a few Pounds to get all the required caps but ages trying to source them all as everywhere wanted minimum orders of 5 or 10, so good old ebay came through cost a little more per capacitor but dont have any left over.

 

[B Trevathan]

but ages trying to source them all as everywhere wanted minimum orders of 5 or 10, so good old ebay came through cost a little more per capacitor but dont have any left over.

This is one of the reasons I like www.mouser.com A while back I needed a capacitor with a high heat rating to go on a power power in a monitor, they had exactly what I need what no minimum orders.

 

[Dameize]

you can tell im immature, I had a chuckle when seeing the threads title.

 

[NBCS]

If a cap is even beginning to 'bulge' or leak, I generally recommend a motherboard replacement. Sure, you can re-cap a board, but oftentimes it's just not worth it (and you never know what other complications it might introduce)

 

[RegEdit]

Sure, you can re-cap a board, but oftentimes it's just not worth it (and you never know what other complications it might introduce)

What other complications are those? Soldering damage?