Fans- No LED's

The first thing a PC does on boot is what's called POST=Power On Self Test then it will beep once it passes that first stage. From what you are saying is that it won't pass POST. Sounds like you may have a bad CMOS battery, or worse. Have you noticed the atmospheric conditions during either occurance? If the MB is cracked, through a circuit path, humidity causes expansion, airid conditions cause shrinkage. When it is humid, the board expands, connecting the paths. All it takes is a microscopic crack through a path and the entire system won't work. Kick it and it comes to life! *chuckle* Bottom line, you may very well have a short someplace.

Before considering it a lost cause, though, I would get inside the box and check EVERY connection. In fact, perhaps unplugging and reseating each individually until all are known good connections. In my experience, I had a couple machines exhibiting simialr behavior. I proceeded to simply remove every device, cable and plug, includingthe power supply then rebuild. Mark all your parts so you dont lose track of where they went. Also reseat your memory sticks.

Good luck!

If you have a Socket A motherboard with SDRAM memory, the fix may be to manually set the FSB and multiplier for the CPU clock in BIOS settings.

I have had this same problem with several different Socket A motherboards, and found the solution posted in a FAQ at www.viahardware.com

It is caused by using the same CPU table in the BIOS for both SDRAM (100MHz FSB) and DDR (200MHz FSB) motherboards.

It also could be a plug-in card / motherboard compatability issue.

I have a couple of video cards and modems that don't get along well with a couple of specific motherboards.

Chas