I've been building a computer for about a week now and I was almost done today. The lights were on, fans were spinning and everything was going great. Until I plugged in the keyboard...

The computer instantly shut down after plugging in the keyboard and since then will not boot. When the power button is pushed, it turns on for a fraction of a second before automatically shutting down. No beeps or any other warning signs. I'm completely lost. Any suggestions?

Thanks!

have you tried booting without the keyboard in

Alright, I think I've narrowed it down to the motherboard. I found a Help section in my motherboard manual that says that the system will automatically power off the system to protect the CPU from overheating. After reseating the CPU and heatsink, the computer stayed on for about 20 seconds, then shut down again. Reseating it again was met with mixed results.

I've gone through all the steps listed in the manual to fix the problem (reset CMOS, check that thermal paste is even across the surface) but nothing seems to really work. I'm about ready to return the motherboard (again). Any suggestions before I do that?


@Daniel3679: Yes, I even tried pulling out the video card, hard drive and CD-ROM drive. Still the same instant shutdown.

did you put enough thermal paste on? are you using a heatsink and fan that came with the motherboard or processor