Accidentally plugged AC power in backwards. The laptop went black. I disconnected and reconnected the battery and it powered the laptop but laptop wasn't charging. then when battery finally reached zero power the laptop shut down and no power was going to the battery or laptop. Even with the battery removed the AC power is not powering the laptop. I tested the volts on the AC power and it's 19v. Tested the DC jack and it too was 19v. Is the problem with the battery or the motherboard what do you think?