I have a problem with a SONY dvd player. If the battery is almost out and i charge it, i can watch videos normaly, but if i unplug it it dies immedietly. So in short the only way i can charge it is to turn it off. Is it supposed to do that?
What does the instruction book say? Maybe because when you are watching a movie on it while plugged in to charge it is taking all the power away from the charge part, makes sense being that the charger is in mil amps