DDJ FLX4 Right deck not working

Hi, there, in my work we have an a DDJFLX4 and the right deck (2, or B) is ni¿ot working. 

I mean, it works, but after some minutes, it stop working, when we push play, in the software (it doesn't matter if is Serato, Rekordbox or Virtual DJ) appers like is playing, but it's stucked, doesn't move, altrought we move the jog wheel, nothing happen