PSU relay click prooblem

I have a dual 2,5 Ghz from June 2004.

It stopped working a while ago i.e. it

would boot with psu fans running but

no chime and no video.

Took out the psu and got it chekked.

It delivered what it should.

But - and here is my question - my

spare machine gives a click when it

receive 220V from the power cord.

And the sick one does not.

Can anyone tell me where this relay

is situated I sure would appreciate it

as I truely have searched all over for

an answer.

Thanks in advance

Torben, Denmark