JVC BR-S611E no image on screen
 

I was hoping someone could point me in the right direction with an issue on JVC pro deck BR-611E.

Basically the unit operates as normal, however i get no image on screen in playback mode. Its completely distorted. I can get a perfect image on still, or in on-screen FF or Rew, but soon as the unit goes anywhere near normal playback speed it goes all distorted.

Any suggestions on what that could be?

many thx