Black screen no post p7n sli-fi tried almost everything

Question

i just got my new motherboard. And i know the heatpipe will get very hot due the 750i chipset.
First i tried to start the motherboard and it worked (out of the case).
Then i wanted to put better cooling paste on the northbridge/southbridge and pcie expander.
So i removed the entire heatpipe, this was very easy and did not require a lot of force.
I found that only less than half the chip (pcie expander chip) was covered with thermal paste (fabric).
i removed all the fabric thermalgrease and put my own zalman thermal grease on it.
Pushed back in the pushpins on the board and i was done.
After that i connected all the cables (8 pins, 20 pins, vga power,) and the hardware (processor, memory and graphic card)
When i wanted to boot the thing it didn't, only fans, leds and a black screen.
I tried everything:
- tried the motherboard out of the case (never went in there though)
- tried cmos reset with power cable remove and without battery
- tried other memory
- tried other psu
- tried other graphics card
- tried swapping memory in different slots
- tried swapping graphic card in diffrent slots
- checked if there are failures (scratches on the board, dust, thermal paste or for bent pinns)
- reseated cables and the cpu
- also tried speaker thingy but i get no sounds at all
But the only thing i get is a black screen and nothing,
If anyone have a idea how i can boot this board... i will merry him/her for sure xD
specs:
e6400 @2.13 ghz
2x1g GEIL ultra DDR2-800mhz 1.9-2.1v
coolermaster realpower m630w
hkc 580w (test)
1x1g kingston memory ddr2-667mhz (test)
2x Asus 9600gt 512mb

Answer 1

Since its worked before your intervention{Replacing the heatpipe}, seems you have damaged something or you are missing something small like power cable or have some shorting issue.