A while Back i Custom Built a Pc for a friend, all was well until a few weeks later when he called me,
he said
when he presses the power button all the fans turn on but the PC does not boot, it will remain with all of the fans on indefinately. he got very annoyed with this and when he could no longer take it he gave it a whack on the top and to his supprise it booted.
all was fine after the initial hit to get it booted, he has told me it does it quite often and all he does is hit it and it boots.
just a few hours ago, i got home from work, went to turn the pc on, same problem.
press On/Off Button, all the fans and lights come on. but no boot.
I thought to myself, could it be the same thing, so i gave it a whack on the top and to my amazement it booted.
my question is, has anyone else suffered from this problem and does anyone know a solution.
the only difference to previously is a new hard drive, i installed XP a few days ago and all was going well till today.

Check your connections they sound like they could be loose hence the whack which in turn allows the pc to boot