Yeah, also if you mobo is gone you'll probably notice blown or distended capacitors. The capacitors around the CPU (there is usually like 10 right around it) are the likely culprit. They don't have to be completely blown and leaking like the pic below but even if they are distended (rounded) at the top they are bad. You can usually tell very quickly if you run your finger over a good capacitor and then over a bad one. They will feel different. Occasionally, you'll see them blow out the bottom instead of the top but that is pretty rare.
