I just built up an ECS L7VMM3 motherboard that I got from a friend who teaches computer repair. I have the manual and feel that I put it together properly, but when I hit the start button it runs for a few seconds and then shuts down. There is never an image on the monitor or any lights on the keyboard. The only thing that I know isn't quite right is that I am missing the bar that holds down the heatsink/fan to the top of the CPU, but I have held it in place firmly and carefully each time I started the computer. It seems to be some sort of failsafe shutdown, but I can't see that I have anything hooked up wrong. Any ideas?

"The only thing that I know isn't quite right is that I am missing the bar that holds down the heatsink/fan to the top of the CPU" That IS Your problem!! That "bar" or clip is designed to attach the heatsink at a certain amonut of force...I remember reading that AMD specs out 12-24 lbs of force to attach the clip. Simply placing the heatsink on top of the CPU & holding it in place is flirting with disaster. An AMD CPU will fry in a matter of seconds without a heatsink...you're lucky your board has some sort of thermal protection. Hey, isn't the L7VMM3 one of those boards that has the integrated CPU? If so...Beware! They are NOT what you think! This issue was discussed a long time ago in the CPU forum. For example, the Pro3000A+ is actually an AXP 1800+ that runs at 1.53GHz, but many people thought they were getting an AXP 3000+ & they were pretty pissed off when they found out the truth. Asus A7N8X-X 1800+ @ 8 x 210MHz 512MB PC3200 Asus Ti4800SE 128MB WinME/WinXP Pro

Hmmm. Thanks. Is there a way to tell if the CPU has been damaged? And yes, it is an integrated CPU. I have no idea what the actual processing speed is.

You can chip that CPU core pretty easily by rocking the HSF over the top of it. A chipped CPU acts like the behavior you describe.

Any way to diagnose a fried CPU or a chipped CPU?

"Any way to diagnose a fried CPU or a chipped CPU?" Remove the heatsink & visually inspect the CPU for any signs of chips, cracks, or scorching. You may have to clean off the thermal material to get a good look. If you don't see anything, apply a fresh layer of thermal paste & reinstall the heatsink...but this time, do it correctly! BTW, while you have the heatsink off, you may be able to get the model number off the CPU core. If you've never applied paste before, there is a "science" to it. You can buy a tube of "heatsink grease" from Radio Shack for about $2, then apply it according to the Arctic Silver instructions: http://www.radioshack.com/product.asp?cookie%5Ftest=1&catalog%5Fname=CTLG&product%5Fid=276-1372 http://www.arcticsilver.com/arctic_silver_instructions.htm Asus A7N8X-X 1800+ @ 8 x 210MHz 512MB PC3200 Asus Ti4800SE 128MB WinME/WinXP Pro