I have a system I built about a month ago. This is an Asus P5K mobo with a E6700 processor, 2x1Gb of Corsair 1066 RAM (PC8500), an OCZ 650W PSU & an Asus 8800 GTX GPU.
It has run fine for the last six weeks (nothing OC'd), until two days ago. Upon a reboot, it will not post up to the BIOS. No beeps, no video output, but all the drives do spin up and all power lights come on. I have tried a replacement video card and have tested the PSU, both are OK. The only other thing I could try was to use only one stick of RAM at a time (which according to the mobo manual it should be able to do). With no GPU or RAM installed, I still get no beeps when trying to boot. My best gues id that the mobo is dead.
if you still get no beeps with no GPU or RAM installed, it sounds like the only thing left is to reset the bios. I would turn off the computer and unplug it from the wall. Once the power light on the mobo goes out, take out the bios and short the cmos jumper pins. Then, replace the battery and plug it back in. You may have already done this. If you have, I would say you have a bad motherboard. especially if all the drives power up and the fans spin.
Also, you may want to unplug and reseat the 4 pin cpu power supply and the 24pin atx power connector just to make sure they are in properly.
Thanx for the suggestions Jedi. To be honest, I've done everything you've suggested except re-seating the CPU. My problem is (as Mike said) CPU or Mobo. Both are still under warranty and I want to get an RMA when Newegg opens on Monday, but the question is how to determine which part has failed. I think I've eliminated the PSU, GPU & RAM, so I'm really down to the two mentioned above.
i figured you had. You seem to be on top of everything. I just thought I would mention it to get it out of the way. I would try reseating the cpu just to get it out of the way. It can't hurt. While you have it out, check the pins on the mobo to make sure all of them are ok. If you have any friends with a 775 chipset, see if they will let you try it in their system.
Yeah, you could try getting your friends to allow you to remove their CPU and install yours to check it. If they agree introduce me, because they are real friends. It's probably your mobo. Just a guess.
Edit: Re-seating your CPU is probably pointless because I haven't heard of a lot of LGA CPU connections failing. That is assuming you didn't somehow put thermal paste on the pins. A failure could still happen but it is unlikely.
This may be very late, but if you're building your own computer, a handy accessory is a POST probe It'a PCI card that tells you what is happening during POST, and also the voltages on your motherboard. They're cheap, these days.