Well, I was setting up my older computer (the one in question) to make a network with my new current machine. So, the other night, I shut off my main computer and let this one do a defrag (just because I figured it needed it after installing a new operating system and such). So,I turn off the monitor and when I come back in the morning, the power light is on and every device is getting power,like normal. I turn on the monitor and the screen is black. I figure maybe power-saving options were on so I move the mouse around/peck at some keys. Nothing. I hold down the power button. Nothing,it won't even power down. So,perplexed, I go to the back and flip the power switch off manually. Then, when I go to start the machine back up, it shows the IDE devices (Floppy,CD-RW,CD drive) getting power. I also hear my old hard-drive spin to life. As well, I hear the power supply fan and heatsink fan start to spin. Everything seems to have power yet my machine will not start. I cannot even get it to show a POST screen or get into BIOS. I tried moving around memory DIMMS, clearing the CMOS, unplugging IDE's (and their power cords), reseating the video card, but nothing. I tested it on another monitor to make sure that wasn't the problem. The thing is though,the heatsink fan doesn't seem to be spinning very fast,indicating that it does not need to do a lot of cooling and perhaps the CPU is blown? I had been moving that particular CPU from machine-to-machine (while I was waiting for a new Athlon XP for my newer machine). But why would it just blow itself out over night? In any case, I am curious to know why my computer will physically power up,but not boot up at all? Any insight and help is appreciated. Specs: MO-BO:(some cheap-older) PC 266 SystemBoard,M805LR Processor: AMD Athlon T-Bird,1.3ghz OS: Windows 2000 Pro Power Supply: 300 Watt ATX IDE Devices: CD Drive, CD-RW Drive, 4.32 GB (5400 RPM,possibly less even) Samsung HD,Standard Floppy Drive RAM: generic 384MB of PC-133 SDRAM Video Card; NVidia GeForce 2 MX/400 Other: AMR Modem/Audio device

Good anyone help me? C'mon I don't want to have to do this,but no one has any ideas. *Cough* Bump.

I think you answered your own question. It seems like you eliminated everything but the cpu. That would be the next thing to troubleshoot.