Grrrrr....PSU / Motherboard problems

[hougtimo]

hey guys,

got a client's PC here. Problem is that the PSU fans, cd drives and the HDD light are all powering up as soon as the psu is plugged in.

The system is a 2.6ghz celeron with 256mb ram made by emachines.

Once it is plugged in and then i turn it on using the power button, everything runs fine (apart from the "system" process using 90-100% cpu at all time. don't know if this problem is related.

I have tried several PSUs, all do the same thing.

What can it be?

I had the computer in the otherday because the previous PSU had blown, so i replaced it and everything went fine. Then 2 days later it has come up with this problem

Please can someone shed some light on this?

[ripken204]

well that used to happen to me on rly old computers..

once you shut it down is it fine?

[Messerschmitt]

Its the motherboard.

My new computer wouldn't power off after shutdown and fans, LED were still keep turning. Changed my mobo and now it works fine

[nmX.Memnoch]

apart from the "system" process using 90-100% cpu at all time

See this thread for that problem.