I have a pic running windows xp. This morning it wouldn't boot.

It doesn't emit any post beeps, and everything seems to power up - certainly the fan spins, the screen, keyboard and mouse all power up. Just in case, I tried it connected to different peripherals, but with the same result. I say the screen powers up because the power light comes on, but nothing whatsoever appears on it.

I also tried swapping the ram stick for one from a working machine, but no change.

It doesn't seem to get as far as a hard disk access because there's no sound from that. Could it be a bios failure - I can't think of anything else that would cause no start up without any beeps? And if it is a bios failure, is there anything to be done

all advice welcome