This is a very common repair problem. I can’t tell you how many times I see a laptop being taken out of the carrying case with the AC adapter still plugged into the unit. Most of the time, if the client did not have a problem with either the AC adapter or the input jack, they do now. Leaving it in like this puts way too much stress on these parts, and they will break. Always disconnect the adaptor and wrap the cords neatly when traveling.
Tripping over the AC adapter cord is probably the second biggest reason for failure. We know better than to leave a cord stretched out across the floor, but we do it anyway, then suffer the consequences when someone trips over it and the laptop gets pulled to the floor, or the power connector gets ripped out. Ouch. Definitely no winners here. Just expenses.
