I have a PowerBook 180C that does not power on and heats up at the connector. I checked for scorches near the barrel and DC-in board but didn't see anything suspect. I checked the barrel connections and found the tip and sleeve shorted to ground. The insertion detect pin works okay. I removed the connector and found that it is not short on its own. The pads on either side of the MLB are also not shorted. Is it possible for there to be a short on the inner layers? Anything I can do to fix that?