Fans whirring, mobo lights on

[KelseyGrammer]

Hi folks.
After cleaning the CPU fan, my comp has refused to boot. Different people have suggested the PSU and the CPU fan were faulty and they've both been replaced, but upon being switched on the CPU + GPU fans start up at top speed and a green light appears on the mobo. No beep, no POST and nothing on the display. I've reseated the CMOS and the RAM chips, and tried running the machine without them/ with one RAM, as well as having tried turning it on without each individual component. In each case, nothing happens beyond the aforementioned green mobo light/ fans. Having looked at similar cases on this site I've narrowed it down to either a faulty GPU (although the fan does start up when I try to turn it on) or CPU (which seems like the most difficult piece to properly diagnose in the world). Is there any reliable way of discerning which of these has gone off? Also, if anyone can think of anything I may have missed I'd be eternally grateful.
Help me, Tom's Hardware... You're my only hope

 

[alexoiu]

Hi, Try starting the board with only CPU and CPU fan connected. If there's a case speaker connected, see if any beeps and if the CPU fan does spin.

 

[KelseyGrammer]

Hey alexoiu,
The fan spins and the green light on the mobo turn on, but still no beeps. There is an internal speaker, it just hasn't spoken up since I tried cleaning the old fan. Does that mean it's either the mobo or the CPU?

 

[alexoiu]

It seems so. Try removing the CPU and checking the socket for bent pins.