Did I kill my Abit KT7? :(((

[TnT83]

Ok, this is my configuration:

Abit KT7
Duron 650@800 (at the time of death), week 31
CoolerMaster DP5-6H51
128MB PC133 MHz, nothing fancy
Asus V6800 Pure GeForce 32MB DDR
Maxtor DiamondMax VL20 15,3 GB 5400RPM IDE
AOpen 52x TKU/Atapi
Yamaha CRW4261t IDE
TerraTec Xfire 1024DMX
Trust 10/100 Ethernet PCI
3x CoolerMaster ball bearing fans (1 intake, 2 exhaust)
AOpen HX-08 Big Tower w/ 300 Power supply

This is my problem:
I bought the KT7 with Duron 650 to do some oc'ing. Before I had the multiplier unlocked, I had it clocked @ 780. Stressed the max temp was 40° Celsius. When I connected the L1's to unlock the multiplier, I set it @ 800MHz. But stressed it got 60°C! So I figured I needed some thermal compound. After applying some compound to the core of the CPU, the PC wouldn't boot anymore.
All it did when I turned on the power was ... nothing really. The hard drive and CD-Rom's got powered, but the screen stayed blank. And you heard there was no activity. So I figured I screwed up my CPU. I bought a new one (Duron 650, week 43, silver core) but the problem stayed. Nothing changed.
So now I think I killed my mainboard.
I already tried booting with the mobo out of the case (to prevent contact with the case) and booting with just CPU, RAM and video installed, but nothing.

What could be the problem? Please help!

 

[Hawk]

Odd, it booted and after you put the thermal compound it won't anymore? Have you tried using the jumper to reset the BIOS...other than that I have no clue.

 

[TnT83]

Yes, I have set the BIOS jumper to reset CMOS and still nothing.

I also turned the power on and off for about 30 times. Because in the manual, it says to do so when you entered the wrong settings for your CPU (I thought the L1 connectors were disconnected and because the CPU was @ 8x100...).

 

[themadmonk]

I read on Tom's Hardware Guide that removing and replacing the heat sink can crack the processor, sometimes unnoticably.

 

[TnT83]

Seems a little odd, since I put the new Duron on the mobo right away. I just installed the heatsink. And on the old Duron, there are no signs of a broken core whatsoever.