The video drum inside the tape mechanism consists of two sets of heads. One set for recording and one for playback. It's possible the playback heads are damaged, in which case the video drum will need to be replaced. It's also possible the video drum may simply be oxidized in and the camera only needs servicing and the drum deoxidized. I don't reccomend using "cleanning tapes" as they can sometimes do more harm thab good although you try. You might get lucky and this will solve your problem.