Computer turns on and off

[yvm2]

Hello,
I replaced a power supply and the computer worked perfectly well for two days. Third day it turns off after a few seconds. I've checked all connections and everything seems in place. Kindly advise what else I shud do?

[0iD]

Do you have another power supply to use, or the old one if it's still working so you can check if it's the new PSU?

[zyce]

The only way to be sure exact what is causing the problem is by testing all components with another machine.

Try the following:
1) Connect the PSU with the motherboard+cpu, no other components (like graphics, soundcard, memory, harddrive or anything). If it stays on, try connecting one component at a time to find out the causing component.

2) If the computer still shuts down, try with another PSU.

3) If the computer still shuts down, try with another CPU.

4) If the computer still shuts down, it's the motherboard/BIOS that's the problem (which it was in my case).

This seem to be quite a common problem with Asus motherboards. I had the same issue, the machine shuts down after 4 seconds, no video was shown.

Solved by the following: I removed the BIOS chip from my motherboard, got another computer with the same kind of BIOS slot, booted it to DOS, replaced the original BIOS chip with my bad BIOS chip, flashed my chip with Uniflash and the latest BIOS firmware for my motherboard and then put the chip back on my motherboard, it now booted correctly and stayed on.

If you don't have the chance to try the above solution you can send me your BIOS chip and I will flash it for you and send back (I live in Sweden). Just post what motherboard you have so I can check that it got the correct BIOS chip.

Rgrds,
Michael

[yvm2]

Thanx for your responses.
I've tried replacing PSU and put the old one back but still gives the same problem.
It's also failing to boot from CD.

[hypnoticstate]

make sure all the connections are firmly in place.