I received a Compaq tower:
Compaq Presario SR1224NX Onboard VGA Windows XP SP2
from a friend.
My plan was to turn this into an Ubuntu Server. It booted up with no problems even with the Ubuntu live disc. After a normal shutdown (not unplugging the power cord and not doing a hard shutdown with the power button), it would not restart even after SEVERAL attempts.
I realized the light next to the power supply would flash very rapidly. I researched and found out it was one of two things: a dead power supply or the cables to the motherboard and to the disks might be faulty, etc. Thus, I checked to ensure the cables were fine(and they were).
I purchased a Power Supply (this one has 400 watts, the initial had 250) and installed it. The tower was able to boot into the live disk and everything. After a normal shutdown, it now restarts but is not sending signal to my monitor. I have tried several monitors in which I know work perfectly but not with this tower (I recall that it did show display after replacing the power supply).
The monitors are ACER. This is different than most "no Signal" problems since I am not using an external Video Card, this is onboard VGA.