I have misplaced the instructions for my Matsui DV3 set top box. When I switch it on, the picture rolls so badly that I can't see the menu. I might be able to figure out what to do if I could get the picture to stop rolling, but without the instruction manual I don't have a clue where to start.
Picture rolling is unlikey to be a tuning problem. Sounds like it is out of sync. You could try reseating the able connecting it to your TV or replacing it with a new cable but if that doesn't work, then I afraid its a trip to the menders. (Or a new box because budget boxes are so cehap now.)