My power supply went and replaced it. I have tried the breadboarding method all except touching some two pins that was suggested because I don't have a mobo manual. I am working with HP 552x pavilion. Nothing seems to work except the fans in the machine. I'm working on my other computer and am afraid of trying out parts from the bad one in case it messes up the good one. I wanted to try the cpu in the other machine but not sure thats a good idea. I'm also wondering if the hard drives are fried because those I tried in the other machine and it will not boot. The bad pc is working with XP and the good PC is a windows ME would that make a difference? Or is the information in the cpu? I did not have to go far in the breadboard only had the power supply all the fans and one stick of ram the monitor and the power button hooked up. Nothing worked. No beeps no boot nothing on the screen. My mobo is an P4S-LA Pentium 4 Intel, 2.53GHz if that helps. I really need help.