PC won't power on

After lying idle for some months I tried to power on my spare PC today but NOTHING happened - no lights, no fan. The PC had been left plugged into the power point with the power point ON for all the time that it was not being used.
I checked that the power was on and that the power lead (to the PC) was ok. I pulled the PSU apart and found that a fuse inside was INTACT.
The PSU is an ATX type with a Pentium II motherboard.
I am assuming that the PSU (power supply unit) has failed but thought that I would ask the question Could it be the motherboard at fault or is it the PSU which would have failed?
Hoping for a quick answer.
Thanks
John

 

Hi John,

You can buy ATX power supply testers for about $15, I think. Of course there is the less sophisticated way to check a power supply as described here. If you have a multi-meter you can check the voltages as well.

Standard disclaimer applies.

Cheers,

ICE