Help with troubleshooting an unstable AMD box

[Andypro1]

Hi. I've been lurking on the forums for a while now because of the good community and great information. Thanks to everyone who makes ExtremeSystems successful!

I need some help determining the cause of a bad instability in my system that started about a year and a half ago after running rock solid for at least a year (I haven't used it in the past year + .5).

The problem:
The machine has many, many errors during a winXP install (attempted multiple times. I'm using a normal, pressed XP CD with no scratches which works fine on any other machine), and when an OS is loaded there are random restarts and crashes (this is the case both before and after the winXP installation attempts). The only peculiar thing I have noticed on the motherboard is the fact that the little fan is hesitant in starting up properly. I usually have to wiggle the wire and tap it a bit to get it moving normally. Sometimes when I start it up, if this fan weren't moving the comp would fail to post. But when I made sure it was running it booted up fine.

The system:
AOpen AK77-Pro(A)133
Athlon Thunderbird 1700+
512MB DDR266 memory (some name brand iirc)
GeForce 5200 128MB (crappy AGP8x budget card, but works)
CD/DVD drive (tried multiple)
Hard drive (tried multiple)

My troubleshooting thus far:
I've swapped out hard drives with no change in behavior, same with CD drives. I've tried just one 256MB DIMM at a time in either slot and then the other, no change in behavior. Tried a different AGP vid card, no change (btw there are no other cards in the system; I took out the NIC). Tried flashing the BIOS to the latest revision for the board, 1.12, no change. Tried resetting to BIOS defaults, no change. I've tried swapping out IDE cables, nothing. (I would swap out the CPU but I don't have any other Athlons to try this with.)

Some further stats:
There is a jumper on the mobo that switches from 100 to 133 FSB speed. I changed it to 133 when I first put the computer together. Below are the temperature and voltages measured from the BIOS (idle, averaged after leaving the comp on for a short time):
CPU: 42C
System: 36C
Vcore(V) 1.74V
+3.3V: 3.31V
+5V: 4.90V
+12V: 12.03V
-12V: -12.52V
VBAT(V): 3.18V
5VSB(V): 5.56V
The CPU's voltage is set to 1.75 (the default I guess), and the 'speed setting' is 133 (FSB I'd wager). The clock ratio is 11, and the proc is running at 1466MHz.

The question:
What can I do from here to figure out the problem, or is it a lost cause? Thanks for your help.

[Repoman]

Can you try it at 100MHz FSB?

Welcome to XS

[lross78550]

i put $50.00 on a bad motherboard. let me know if i win
Lee

[Andypro1]

Can you try it at 100MHz FSB?

Welcome to XS

You know, this was my next step! I tried this and it has (so far, knock on wood) fixed the problem. Thanks for the suggestion!

I did a clean XP install with no errors. So far so good. I'd like to stress test this thing (now at 1.1GHz). Now that I have the OS stable I'd like to mess around with the stepping a bit to see how close I can get to 1.4 without going unstable again. Any suggestions for a good stress test?