No display even before BIOS

[lagagnon]

I am assuming you see no text on the screen at all and do not get the POST completed beep? If that is the case then you have either a:

1) faulty video chip
2) faulty CPU or motherboard
3) faulty power supply system

(in that order of likelihood)

If you do get the POST completed successfully beep and still get a black screen with no text whatsoever then you have either a:

1) faulty LCD screen/monitor/video cable
2) faulty CPU/motherboard (somewhat unlikely if POST completes OK).