OK so we have a Dell that stopped working the other day.
It just wouldn't turn back on.

No response from power button or any LEDs on the case which have showed response when motherboard has blown before.
 
Opening it up the power LED on the motherboard is working.
My next thought would be the wires from the power button to the motherboard. Being a Dell they don't use the normal wires from a power button they have a separate card with power button, status LED's, USB's, and Mic ports mounted on it connected via IDE style ribbon cable (but not IDE) which looked a little bent up in some places but all insulation is in tact from what I can see.

Does anyone have any ideas on what else might cause the computer to not start up?
Is there any other way to start the computer up or any way I can test the cable or power button without using another computer?