Hi, when I start up my desktop the monitor stays in standby mode and the motherboard beeps. I understand beep codes but this is just a beep every 3 seconds that's what confused me. I cleaned up the dust from all the fans and connectors in the computer but still no luck. The hard drive light stay's bright orange like it's loading somthing, no lights on both keyboards I tried, DVD-Rom and DVD burner trays still open and close and the fans still work.
The power button dosen't shut it down so I have to unplug from the mains.

The PC is Windows XP Home SP2
120GB Hard Drive
512MB RAM
PhoenixBios

Any help is much appreciated, Thank's

Welcome to the forum, have a read of THIS first to see if it helps.