Gary most likely hit the nail on the head, but I have ran across a few
strange things to happen with system experiencing what you are. One was the
switch to turn it on and was struck inward and the other was the reset
switch. If this is the case you will get no power at all, so check these two
things and make sure they are working. Also check the power supply as some
come with a On/Off switch on the back and I've seen them get turned off when
the system gets moved.