jack polarity on Xoom tablet

OK, the problem was with the cable from the charger to the jack. The jack is molded inline on the end of the cable. When it is plugged into the tablet and the tablet is resting on a lap and the cable routes to the side. The wires can not accommodate any sharp bending at the jack. When I cut the cable from the charger and chased the continuity the wires were shorted going into the jack molding. I was able to remove enough of the jack molding to re-attach the wires. I made up a right angle connection to the jack with RTV molding so the wires won't see a sharp bend. The charger seems to have put up with the situation and outputs 12.06v. So I guess all I can say is be careful not to kink the cable.