Errors while booting or after it's running

[razey]

I just recently got a computer booting after replacing the power supply. However, after the first time it turned on again it crapped out and hasn't worked once since. It has turned on and worked fine for awhile. It doesn't crap out at any certain time. It can do it while booting in bios or as far as fully loaded into windows. I have tried various hardware thinking it was a conflict in some piece of it. The only possible combination I can come up with is between the power supply and the chip or the power supply and the mobo. The vid card, hdd, sound card, modem, power supply were all in another computer for awhile working perfectly.
Another possibility is the chip is over heading, it's a 1ghz amd athlon k7 w/ the proper fan+heatsink it's always ran hot between 40-50 celcius. I have not had errors like this before but my friend believes this may be the cause of the random errors because all of the hardware is the same.

The current specs are:
1ghz amd athlon k7
soyo k7 via mobo
turtle beach santa cruz sound card
diamond viper 770d vid card
generic 56k modem
linksys 10/100 ethernet
pny 128 meg pc133 ram

 

[Antimatter]

What are the voltages like(PSU 5V, I/O voltage and CPU core voltage)?
I'd suggest a failed voltage regulator as the most likely cause of the problem. Check around the CPU for bulging capacitors or residue around the base of them.
Have you tried resetting the BIOS?
Do you have a POST error code?
It might be worth reprogramming the BIOS if you have a similar mainboard available for hot-swapping or a universal programmer.
Another less common problem that might be worth checking is dry solder joints on the mobo PSU connector.

 

[razey]

The errors take longer to occur after the computer has been turned off for awhile. Upon the original breaking down of this comp I did take out the battery on the mobo to see if that would have done anything.
I just got another error while installing win 98se, here it is word for word:
An exception OE has occurred at 0028:C022B978 in VxD ---. This was called from 0027:C00500F7 in VxD .... and it just shut itself off.

 

[SyberK]

Why did you replace the power supply to begin with? Was it because of a power surge? Any background information could be helpful.

 

[razey]

The reason for replacing the powersupply was because at a friends we had gone to get food upstairs, I left my computer on, and when I came back it was off, upon trying to turn it back on there was no response.