spiderman said:
diagnostic lights stay off at start up,i have tested the power supply
and i'm sure it's good!
You can try simplifying the setup, and see if the response changes.
If there is more than one stick of RAM in the machine, try it with
only one of the sticks installed. It could be a RAM failure. I had
a RAM failure, where the RAM held the lower 640K, and the BIOS wouldn't
beep or anything. I was able to start, by moving the RAM around
(so the dead RAM was still present, but located above 512MB). It
actually took a number of test cases, and a spare stick of RAM,
until I could make a configuration that would start.
You can also unplug the IDE ribbon cables from the motherboard,
in case, somehow, a failed drive is able to stress the Southbridge.
While you're inside the machine, that will give you a chance to inspect
the capacitors. So far, I haven't lost any motherboards to bad caps,
but did have one Antec power supply fail a couple weeks ago. The
brown stuff was on top of the output side caps. The power supply was
still running, but outputting poor quality power (caused the hard
drive to attempt spinup several times, before starting properly).
Paul