Sudden no POST, Video. Intermittent asus voice code "no cpu installed"

[tnerbrellim]

I built a computer a little over two years ago, and I've never encountered any problems with it until this week. Recently it began to occasionally freeze up, requiring a power cycle to fix. After this happening about four times (it would lock up while I was not there, and I would come back to find it locked) and upon a restart, I recieved no post and no video.

My system is:
Asus p4t533-c motherboard
p4 2.53 processor
Nvidia Geforce 5700le 256mb card
Guillemont Hercules Gametheater XP
256x2 RDRam modules (kingston)
vantec stealth 500w power supply
mcx-4000 heatsink and thermaltake smartfan II on the CPU

I tried swapping the video card with a known working one, same result. Monitor works on another computer, no difference if RAM is removed, tested the PSU and it's pushing the right amounts, reseated all cards and my CPU, and I tried running it out of the case barebones. All give me the same result: Board powers on, fans start spinning but no video. 70% of the time the ASUS voice reporter gives me a "NO CPU INSTALLED" warning, the rest of the time I get nothing. Took out the battery and cleared the cmos, checked all my jumpers, still nothing.

Can anyone help me? I've run out of ideas and I'm not sure which parts if any have died. I don't have access to another mobo, 478 cpu, or sticks of rdram to test.

Thanks in advance,
-Brent

 

[vegasgmc]

Have you tried removing and then re-seating the processor?

 

[tnerbrellim]

Yes, I reseated the processor - no chips, scorches, or bent pins. Was using arctic silver and I always monitored my cpu temp.

 

[tnerbrellim]

Does anyone have any ideas how I can fix this? Does it seem like my motherboard or cpu has gone? If so, which is more likely and how could I do tests to make sure?

 

[vegasgmc]

See if there are any computer shops in your area that can test a processor. But the only easy way is to swap parts.