system has power but not booting

hi

i have a pc that is not booting up, when i plug it in there is power there the fans kick in and the lights are on but there is nothing getting to the screen

no sounds comeing from the motherboard (beeping ect)

when first pluged in and switched on at the switch on the power supply the fans start to spin straight away (pressing the button on the front of the case dosnt do anything)

i was wondering if anyone had an idea of what to check?

the pc is an emachines 210
pentium 4 power supply

 

Do you hear the computer trying to start? Meaning maybe it's starting but no video output. Do you hear any beeps at any point?
Check the power supply with either a cheap tester made for this or a multi-meter. The motherboard may not be getting the proper power.
Tester link.
Testing with multi-meter.
Disconnect all connectors to the motherboard and reseat them. Remove the RAM and reseat that also.

If the above does not work more than likely your processor or MB went south.