Replaced heatsink on q6600 p6n and computer doesn't post now

Hi all,

I recently had my temperatures skyrocket in my system I've had running for 2 years. I figured the thermal grease had deteriorated and took the opportunity to upgrade my heatsink. I bought the Tuniq Tower 120 v2.

The only problem is... when I hooked everything back up, the computer wouldn't post. So I pulled everything off the case and put just the motherboard, ram, cpu, heatsink, and video card on.

The specs on my system are:

OCZ Powerstream 550w
quad core q6600
msi p6n platinum 650 sli
4x corsair xms2 1 GB stick
EVGA GeForce 8800 GT

Again, the only things that are connected are the vidoe card, 1 stick of ram, HSF, CPU, and the power switch.

The computer turns on, all the fans come on, the DVD-RW I connected to the PSU opens and closes. I connected the monitor to both DVI ports on the video card, but nothing ever comes up. Plus, when my computer was working, the RPM of the fans would initially ramp up to full speed and then go back to normal. Right now, it doesn't post and the fan speeds stay at max until I power off the computer.

I've read the guidelines to follow over at

http://www.tomshardware.com/forum/261145-31-read-postin...

before posting here, and went through everything twice.

I'm running out of ideas, any suggestions? Thanks ahead of time.