Well, this morning i woke up and found out that my computer was turned off, and i always leave it on over night doing something. I thought it was weird, so i went to tunr it on, and to my surprise, the monitor wont boot up

. The computer turns on, all fans and lights activate, and start up, however the computer will not POST (Beep) and an error comes up on my monitor saying:
Signal: No signal
Connection: Connected
Which means that it can read that it is connected, but does not register that the computer is actually on and running and therefore not getting the signal. Since my computer doesnt even POST, im assuimng it is an mother board problem. Does anyone know if it is fixable or do i just plain need a new motherboard....
Ive already tried fiddling with the graphix card, which does nothing but make my monitor lose connection and regain connection when i take it in and out. Please help

Update: well it seems i fried my CPU, and now i need a new one. Any suggestions for good cheap ones?