Ok, mates pc wont power on - im 200 miles away and the chap is a doughnut.........

The mobo is a A7N8X-E (Asus), the power cord goes into the PSU and the standbye LED lights on the mobo.

Current checks so far, running out of ideas now.....

Reset Cmos
Changed Power leads
Changed plug sockets
Removed Ram
All fans plugged into MOBO
Swapped reset button for power on button

Now the only bit of decent info ive had is that when you "wiggle" the power cord at the back, then the green standbye LED flickers. Duff psu perhaps?

On wiggling of power cord it booted, without pressing the on button. - whilst on teh kitchen table, yet when returning it to the pc the thing wouldnt boot.

What happens when you press the power button?

nothing, no noise, no fans, standbye led stays on.

Blown Board?  Could be a blown PSU even if the 12V rail has gone.  

What happens when you short the power button pins then?

Quote from: sdpWhat happens when you short the power button pins then?

nothing, just sits there looking at me

Quote from: madocks

Quote from: sdpWhat happens when you short the power button pins then?

nothing, just sits there looking at me

Checked that the power capacitors arent blown?  

Tried a different PSU?

If theres a light on inside the case then its getting power, check all leads are in place. Pull all the power plugs, noting which goes where, then plug in motherboard and graphics card only. Try booting. That will give minimum power needed. After that it could be the motherboard or the PSU. If he gets it to post then its a case of trying to put them back in one at a time.

Some Mobos now have a switch for upgrading on them, unlikely but might be worth checking if hes hit that by accident if it has one.