I'm working on a PC at the moment. Intel P4 3.0GHz Socket 478 CPU, 512MB DDR Intel RAM. When I got it, it had an intermittent power failure problem, more off than on. I eventually managed to get some power to the mainboard and determined that all in all the motherboard was shot. I have changed the motherboard (installed AsrockP4i65G), PSU (350w) and VGA card (all of which didn't work). At first the machine powered and booted up with no problem. I tested the memory with SIMM Tester and that all passed ok. After booting it up and shutting it down 6 or 7 times it has developed an intermittent power fault again. The pattern is, only the power LED comes on, no HDD LED but the machine doesn't boot. I unplug and leave for a couple of seconds and plug in again and it's dead. If I leave for a couple of minutes and try again it powers and boots up no problem. Before I decide to jump up and down on it, any suggestions please! Happy New Year by the way!