Sony dcr-trv120 playback (by 2 users)

hi all
i have a sony dcr-trv120, recently it developed a problem with the playback, on screen the picture started to go pixelly in 3 lines across the screen now it has 3 grey lines (no picture) but the rest of the screen shows the picture perfectly, i have tried head cleaning tapes but as the picture is so good on the areas that work i can only assume something has failed with the pickup of the picture from the tape, if i playback to a tv the same occurs

thanks for any help
tim