No Post- Motherboard or Cpu? Stumped.

The motherboard is an ECS RS400-A; the CPU an intel p4 3ghz w/ ht... can't recall the model no# atm. Anyhow, I decided to format my hard drive and reinstall win XP home edition- had some problems with a corrupted ghost file and an online game's launcher that could never finish "updating."

After the reformat and reinstall- the PC gradually began to POST less and less frequently- to the point where it seems to no longer POST at all.

I've removed, reseated, cleaned all components except the cpu several times.

I've stripped the motherboard down to CPU, ram, onboard video, removed from case; tried to boot problem persists. That was a couple days ago; at that time it seemed to post more frequently in this configuration- this seems to no longer work.

I've tried different sticks of RAM one at a time. I've tried booting with no RAM; sometimes the motherboard beeps telling me to feed it RAM; some boots it does not.

When the comp does boot- it boots all the way to my desktop- with intact file structure; everything right where i left it. However it will reboot in an hour or so when it warms up; or just lock up.

Also; on those infrequent successful boots- there was no short "everythings ok" post beep.

The fan attached to the rear of the power supply unit functions normally; and all other fans will work; as will 5 cd\ide\floppy drives. I'm serisouly doubting faulty power supply.

Now because of the "sometimes" behavior- I'm suspecting a bad capacitor on the mobo- but looking over the mobo; i see no brown goo and no obvious bulges. I hear they are not always apparent.

As for the CPU- I overclocked it to 3.4ghz previously and ran it for about 3 months without a voltage increase; and it idled at 38-40 celsius. I also had a shut down temp set at 60 celsius. I monitored the temp constantly and it never broke the low 50's under heavy load. But I have had another processor of the exact same model die on me previously without any OC'ing in less than 30 days- so im suspicious of it...

but when CPU's go bad; they don't "sometimes" work right? I mean- I made it to freaking windows and ran for about an hour... Mobo capacitors can act up from what I understand; when they get warm and expand... The machine I'm on is AMD based; so i can't just swap the CPU to check it.

What do you guys think?

 

And it turned out to be a faulty motherboard. Got a new asus board today and all is well- I didn't feel like waiting around on shipping from newegg- so I went to a computer builder's warehouse and yeah; the techs there had never heard of such a problem either.

 

ECS mobos are know for being crap, that is what frys uses in thier GQ computers.good choice going with an ASUS.