Is the back door on the machine?
Are you getting AC power to the power supply?
To the monitor?
Does the monitor neck light up?
Do you hear ANYTHING out of the speakers (you can usually hear some sort of hum or something if the audio amp is powered).
Do you own a multimeter?
Does that machine have the kind of monitor that has no frame, if so, then that is a nice monitor, you might want to see if the monitor works before giving it away.