Is it the PSU or something else.

[11mahesh11]

My old system with the following config

400w PSU
Sempron processor
Asus A7V400-MXSE Board

The problem is, the system suddenly shut today, while in usage.
Earlier the same system used to usually give a keyboard lock message when starting.(so I used to disconnect the keyboard cable and connect again, and the system would start without the lock message)
Recently the system was not powering on at first attempt but would do when I remove the power cable and connect again to the PSU.
Now I am not sure where the problem lies , whether it is the PSU or the motherboard or the UPS ?

Any take on the above.??? :$

 

[mikeymikec]

PSU or mobo seem likely. A cheapo PSU just for testing should answer one possibility for you.

Alternatively you could try running Prime95 on it for half an hour to see whether it fails under load, but that doesn't definitely point the finger one way or another.