bad 820uF 6.3v caps in HP pavilion a867c PC

[wa2ise]

A few weeks ago I changed some of the memory modules from 1/2 gig to 1gigs. To now have 3 gigs of ram. Well, now the system would occasionally freeze. Bad new memory? Maybe some SW I've been running doesn't play nice in the system? Well, I decided to pull the new memory and replace it with the old ones. But I noticed a pair of green "Ltec" 820uF 6.3v caps had bulging tops. Right near the memory. Got out the tools and soldering iron, and found a couple of 1000uF 10v caps 105C as replacements. Noted which circuit board hole gets the negative side. Put the system back together and it still works. Though it's too early to declare success, as the freezes happened every several days... I did check the old caps with a cap meter, they measured less than 0.1uF. Looking closely at the bulged tops I can see a crack.

All the other caps look fine, no bulges or leaking crap (at least I can't see it if there is any).

I bought this PC new in 2005.

[mockingbird]

Re: bad 820uF 6.3v caps in HP pavilion a867c PC

Is this your board?

http://images.esellerpro.com/2131/I/719/31/5187.jpg

Lots of re-capping to do. Starting with those 8mm KZG series cap in the VRM high.

[wa2ise]

Re: bad 820uF 6.3v caps in HP pavilion a867c PC



The caps I arrowed in your mb picture and my picture of my mb are the ones I replaced. The replacements are 1000uF 10V 105C. And about twice the physical size as the old ones.

The bad caps:


The system's been stable since my last post last week.

[mockingbird]

Re: bad 820uF 6.3v caps in HP pavilion a867c PC

Don't put a better CPU in there. The moment you put some stress on it with a higher TDP requirement, the weakness in the caps you didn't replace will manifest. KZG can last for years working at half their capacitance and out of their ESR spec as long as the power demanded from them is a fraction of what they're rated for.

[Pentium4]

Re: bad 820uF 6.3v caps in HP pavilion a867c PC

I believe this mobo has GSC caps on it too....