Reply 80 of 83, by Cyanopsis
Update (for documenting purposes):
First of all - a recap: the title of this thread is misleading. What first looked as faulty bios turned out to be the wrong bios flashed on an eeprom with insufficent ram. After that was settled, bios settings couldn't be saved and the problem lied somewhere between the battery and the vbat pin on the southbridge chip. Probably beneath it!
I got a new identical board from ebay, but wanted to use this faulty board as a practice board for repairing. Got myself one of those Andonstar microscopes and some ChipQuik low-melt solder and started removing the southbrige (vt82c586b). Not exactly easy as a first step, but I removed it eventually. Unfortunately, I broke one of the pins in the process. I have ordered a new one.
The culprit was immediately visible - a corroded via trace on the 3v line from the battery that needed fixing using a single strand of copper wire. Now there's continuity all the way from the battery to the vt82c586b southbridge chip!
Still to early to tell if it's been completely fixed until I got the replacement chip, but I'm not giving up. I've spent too much money on it already! 😀