haydelnathan :
I read that it might be some kind of short circuit
Maybe, but since you mention no drop or liquid damage, the easiest/logical thing to blame is an easily replaceable charger than open the laptop (do you have experience working with tinny electronics and have tools?)
I would just take into Best Buys, have them plug in a good charger, they may not even charge you anything for that, and if charger not at fault, well then you can decide whether to let them work it further.
If u feel like adventurous, can open it on your own, careful with delicate cables u can break, and check it out, maybe a bug got in there but todays electronics are so tightly packed kinda doubt it.