Hi, I built a new computer. after i turn on the pc, the power is up and all the fans are spinning. after few seconds, the pc shuts off and turns on again but do not boot. Can anyone please help. Thanks

This may not be what you want to hear, but here goes. Remove the motherboard and place on a flat dry surface. We are doing a bench test. Connect the power supply and front panel connector. If the front panel leads are to short use a screw driver to short the pins. Connect the keyboard and mouse. Remove the ram. With hard drives cdroms and floppy drive disconnected see if it will start....we know it wont...we want to see if it at least beeps. If it beeps. Connect monitor....try again...still looking for beeps. Install one stick of ram. Restart. Did it beep? Second stick of ram. Restart. Hard drive Restart cdroms and A: drive By doing this you find the point at which it is failing. Be sure to unplug the power cord between operations. Before reinstalling the motherboard give the case a good shake to to make sure there are no loose screws rolling around. All it takes in one behind the motherboard to keep the system from booting. Post back where or on what test it fails. Hope this helps.

The CPU might be getting overheated. So check if the heatsink is seated properly over the CPU, and the fan is spinning. Also, if there is any dust on the heatsink and fan, then clean it. Anupam