PC Keeps turning off in BIOS/DVD Boot

[Drake5]

Purchased a system from the MM that just needed a PSU.

I put in one of my spare PSU's that was working fine only 1-2 months ago.

I'm trying to install an OS but in the BIOS or when I boot from the IDE DVD Drive, the PC just turns off completely.

I thought it might have been a faulty dvd drive but I took it out completely and the system still turns off when in the BIOS.

All the connections are plugged onto the mobo correctly.

Any idea what could be causing this?

Cheers

 

[Garfo]

what power is the psu you are using?

 

[Garfo]

oh and specs?

 

[Drake5]

I just tried another PSU I had and the exact same thing happens. It just cuts out.

Specs are:
E6600
4GB DDR2
gigabyte 965p-ds3 MB

 

[Garfo]

cpu all seated right?
wires all in right places?
graph card sat in good?

 

[Garfo]

also try booting with 1 stick of ram see ya mobo book

 

[Drake5]

cpu all seated right?
wires all in right places?
graph card sat in good?

Yeah all cables in fine. reseated gpu twice.

also try booting with 1 stick of ram see ya mobo book

tried that, still exact same. :[

 

[esK`]

possible overheating? check the cpu temps in bios!

 

[Garfo]

possible overheating? check the cpu temps in bios!

this

bang some paste on it

 

[Drake5]

this

bang some paste on it

You were right guys. I reapplied the heatsink for the CPU and realised one of the push pins wasn't down correctly!

 

[Garfo]

no probs m8

 

[Drake5]

Really appreciate the help on here. Top class!