A friend of mine brought me his laptop because it stopped booting. I tried booting it a couple of times and it wouldn't boot. Then I plugged it in an external monitor and it booted OK. I turned it on several times after that and it booted fine. He took it and a couple days later it wouldn't boot again. In our conversation I found out he was plugging his adapter into the electric and then plugging it into the laptop. I told him to plug the adapter in the laptop first and then into the electric. He did and it booted right up. Could plugging the adapter in first before plugging it in the computer possibly damage the battery and cause these symtoms? If not, what could?