Dell Latitude CPx -- my sister was having trouble with it (didn't always want to turn on)..one day it refused altogether. I messed with it - with battery, with AC, etc..and eventually noticed a burning electronics smell, and saw some faint smoke coming out of the laptop. Alrighty then..apparently something is messed up.

I disassembled it today - found three loose screws inside (bouncing around )..removed the motherboard, plugged in a keyboard & monitor, plugged it into AC power and then heard a light whine coming from the center of the board. It refused to power on. Is this a bad power supply, bad motherboard, or..?

Ideas would be great..