Installed New Heatsink, now Computer wont boot

[NinjaSaywhat]

Hey guys!

I recently installed a new heatsink into my homebuilt computer and now im having some issues that are quite upsetting.

Components are:

CPU: i5 3570k
MOBO: GA-Z77X-UD5H
PSU: Corsair CX600
GPU: HD Radeon 7950

After installing everything, I try to boot the computer but the only thing that happens is all the fans and lights will start up for about 1/8th of a second, and then everything stops. All while the little power button on the inside remains illuminated the entire time.
When this happens, I try pushing the regular startup button on the front of my case and nothing whatsoever happens, only after switching the switch on my power supply off, back on and THEN hitting the front button on the case will this happen again.

Any Ideas? Please help!

 

[clutchc]

Sounds like the motherboard failed. When you removed the stock cooler and installed the new one, did you do it with the board still in the case? What cooler are you using? If it required a mounting bracket on the back, be sure you haven't grounded or shorted out anything on the back of the board.