MB or CPU is dead?? How can you tell?

I've been struggling with this for a couple weeks now. My HD crashed, so I buy a new one and try to install Windows XP.

Constant blue screen errors with all different messages, so it must be a hardware problem, right? I started pulling and replacing all the cards and drivers when I notice the CPU heat sink rattling like mad. One of the clamps holding it in place snapped and it came loose from the CPU.

I took it all apart, cleaned it up and replaced with new thermal grease. Now it will not even boot. Fans and CD drives power up, but just a black screen. No beeps or any sign of life.

This is a four year old HP with Pentium 4 processor on a ASUS board with upgraded video and sound cards. All had been running fine until the HD crash.

Is there something I could download and burn on to CD from another computer to troubleshoot my dead one?

Any advice would be appreciated...I'm about ready to turn this thing into a planter.

 

The only sure way to tell is to test with a known good CPU or board. However, 9 times out of 10 it will be the board, not the CPU.