I am having severe trouble with my new system. When I start it up it will go for 3-4 seconds (fan, hard drive, etc. all running) and then it shuts itself down. No beeps, no bios, no monitor output, no nothing. I have searched everywhere and tried everything suggested, but to no avail. I have to assume that something is not working and that I need to replace it, but I don't know what. Any help is appreciated. Here's what I've tried so far... I went jumperless - no change I took everything out except for the CPU, speaker (to hear beeps) and power supply. - no change I took the MB off of the chasis (in case of a short) - no change I plugged a fan into the the CPU fan slot (seems some mb's need to think there is a CPU fan and mine uses a 4 pin not a 3 pin plug) - no change I reset the CMOS (battery/jumper sequence), but to no avail. I've tried every combination of having things plugged in or not plugged in - no change except for what is mentioned below One thing I can do to make it work differently is to take out the CPU. No matter what I have plugged in, if I take out the CPU it will start up as mentioned, but it will not shut itself off. Still no beeps, no bios, no monitor output, no nothing. But at least it doesn't shut itself off. System Hardware: Asus A7N8X MB Corsair 512MB PC3200DDR Athlon XP 2400+ Albatron geforce4 Ti4200 Video Card Western Digital Harddrive Samsung DVD/CD-RW Swiftech Heatsink & 60mm fan Please, somebody help me!!!!

what do you have for power supply?

Enermax EG365P-VE(FC) In other words, a really good 350w supply.

Just had one that would run the CPU fan, and the power supply fans, but would not POST, and acted as you describe yours. Have you tried it with just the Power SW case cable and the HDD cable connected to your main board? Is this a new case, or have you used it before? What I found was my new case had a reset switch in the case that stuck in the closed position after I pushed it the first time. "Some hours later", when I tried a different board in the same case, I discovered the defective switch. When I reinstalled the original board (ASUS A7N266VM with just the HDD LED and the Power Switch, it came to life. Paid some dues on this one.

I bet that was a hard one to track down! At one point I had 3 things plugged in and that was all. The PSU, the soft power switch and the internal case speaker. Still no beeps. FYI...it is a new case. Thanks for the reply! I tried again just to make sure and received the same results.

hello the problems with your cpu. as you said every thing else seams to work with it out. seval things can do this to high a giga hertz cpu for mother board. to low a front sode buss rated cpu or to high. heat sensor for cpu report roung info such as saying its to hot when its not. if mobo has manual clock speed dip switches make sure there set to auto. make sure bios is allso.

i agree with waradave the cpu is the suspect did you buy it froma online store ? if so mailv it back and pay the restocking fee if needed, and get another one it should post, if not the motherboards dead..