reboot - PC booting and rebooting repeatedly without completing POST

I have a custom build PC:

• Corsair HX620 PSU


• Intel 6870 C2D


• Geforce 8800GT



• Asus P5Q-E

I've recently moved from the UK to Canada, upon plugging my UK built PC into the wall socket it gets stuck in an infinite loop of booting and rebooting, the fans spin, internal and external LED's light, but no output to the monitor.

My HX620 apparently will auto select the right voltage, but I can't rule regional issues out, I am using brand new Canadian plugs, straight into the wall socket.

Tried the following:

• Reseat graphics card - No effect


• Remove and replace battery from motherboard - No effect


• Disconnect HDD - No effect


• Disconnect Graphics Card - No effect


• Disconnect CD-ROM - No effect


• Reseat RAM modules - No effect


• Remove 3 RAM modules - No effect


• Swap remaining RAM module with one of the 3 removed - No effect.

Answer

If things look OK physically (ie: heatsinks, etc.) then if you remove your RAM, and you get no POST beeps telling you you have no RAM, your motherboard or PSU is probably broken/malfunctioning.

Amongst what others have suggested, you can try:

• Try a different wall socket, and if you have one, a different mains cable.




• Determine if on-board power-good LED is staying lit steady during these power cycles, if it's turning on and off with the power cycles, then it's probably the power supply.




• Reseat (unplug and replug) all your power taps. I see that PSU has modular plugs, so do it to both ends. Triple check that the 24-pin ATX cable is 'clicked in' all the way.




• Unplug all drives, take out everything except the CPU, RAM and Video. If it works, then start plugging stuff back in one at a time until you find the culprit.




• If it still doesn't work, then the next thing to try is a known-good power supply. You may want to try this before the previous suggestion if you have one kicking around. :)





• If that doesn't fix it, it's more than likely a busted motherboard.