On optical drives, there's rarely an electrical adjustment for focus. The symptoms you are describing could indeed be a focus problem, but electrical ones are rare. Much more common is a bent mechanism. The optical assembly moves radially along a track that has to stay fairly parallel to the disc surface. If the frame and track are bent relative to one another, the focus will change from the inner to outer tracks. Your drive's behavior is consistent with the focus being good on the inner tracks, but not so good further out. Since the optical assembly is anchored solidly near the spindle, that's exactly the behavior you'd expect from a bent frame. Open up the drive and look at it carefully as you slide the optical assembly along its full travel. I'm willing to bet that you'll notice something is bent. If not, post back.