I opened up my ps2 to clean the inside, mainly the lense. (pos read disc error) and i slipped and rotated this white dial. I put it back in its original spot but it wont read the discs very good. Ive only tried 2 dvd games and a cd game and the only one that booted was the cd disc. I had to stand it up veritcally. Here are some pics of where the thing-a-ma-bob was.