rs media

Hi there, My sons dad bought him a RS media but when he went to charge it put the wrong charger in. This caused a small puff of smoke from the back. Now it comes on says he is running out of power and turns off.Now, i am ok with some electronics but when opening the foot i realised how big a job it would be. I have no clue where to start on one of these. If anyone can give me some thoughts and ideas as to what this could be and if there is anything i can try and do to fix it. Seem such a shame to get rid without trying something. We tried battery power but even that didnt work. My son is gutted.Thanks in advance