any add on PCI cards? try running just the CPU, RAM, and see if it boots
then add external video card, hard drives, etc.
I tried to boot without PCI cards. It had no effect. I changed my graphic card (the only PCI device), no help. I'll try to remove hard drives without system, I'll report if it works.
I tried running just cpu and ram, same results. I tried to remove RAM, no beep occured. I tried to switch RAM, nothing happened. On the fifth turning on my computer boots normally and is stable I do anything. Do you have any idea what migth be wrong?