Gigabyte GA-8S655FX Socket 478 Motherboard Refurbishment:
I have been looking out for some old Socket 478 Motherboards to build a Windows '98 PC around and stumbled across a cheap local PC that contained this motherboard along with some other odds and ends that were interesting to me.
This Gigabyte motherboard boots and operates fine, however after looking closely at it, I could see that three capacitors were badly bulging and it is well known that a capacitor plague was haunting a lot of motherboards from this era (1999-2003):
These were promptly removed:
and tested:
Very bad ESR as expected, but on closer inspection you can also see that not only had they bulged and were leaking fluid from the top they had also ruptured at the bottom of the capacitor:
All the bad capacitors were Chemicon KZG (3300µF 6.3v 105°C) which is a known BAD CAP.
I checked the motherboard for any other KZG type capacitors to remove but did not find any.
For my peace of mind I then in circuit tested the ESR of the other capacitors and found they were all in good standing and the ESR was mostly reading at a very good 0.2Ω reading.
I however did not have three new 3300µF 6.3v 105°C capacitors at hand, but I do keep a tub of capacitors I have removed from junk boards (or from complete recaps) that test good for ESR and capacity:
It is especially good to save the large high voltage capacitor from junk devices as they are expensive to replace and rarely go bad.
In here I found three suitable replacement Rubycon MBZ capacitors.
These I re-tested before soldering them into this motherboard:
Lastly the original CR2032 battery was dead as expected so that got replaced with a new one.
This motherboard is now good and safe to go again:
