Great. I have a Pentium 4 515 cpu lga775 mounted on the motherboard but when I put power "ON", the chassis fan "whirs" up to speed, then ramps down to stop as if only "momentary" power is received. The power "ON" led remains lit but the monitor shows "NO SIGNAL". The original mother board (210882) used DDR memory but the new board uses DDR2 memory. I am afraid the original P4 515 CPU didn't recognize the DDR2 memory and I'd need to change the CPU. Am I on the right track?
All the connections were fine. After doing a bit more research, I rotated the HSF 1/4 turn and got "promising" results. The unit began loading the OS but shut down before the OS was loaded completely. It powered on for the same amount of time with every start, but never completely loading. , , , MORE RESEARCH, , ,I removed the "old" thermal paste and applied "NEW" thermal paste between the HSF and CPU. SUCCESS!!!!!! I had installed 2 new 1Gig memory (DDR2) sticks and found that the computer did NOT recognize the second stick. RAM showed as 1Gig instead of 2 Gigs. I swapped the memory sticks to determine what configuration worked, only to discover that one of the new memory sticks seems to be "bad". I'll be replacing that stick and I should be up to 2Gigs of memory very soon.
I HOPE THIS SOLUTION HELPS SOMEONE ELSE. AND I THANK YOU FOR YOUR HELP AND EFFORT WITH MY PROBLEM.