I noticed that many times when you replace a lens it throws of the rotary motor. Some ps2 consoles have only 1 hex adjustment yet others have 2. If you have the covers off and just replaced the lenses you should always plug it back in w/ the top off still and adjust it until you see the disc spinning rapidly and laser is moving back and forth. Another way for calibrating is to remove said disc and if lens and ribbon move all the way forward and all the way back 3 or more times then you are almost done. At that point plug in tv chord and place in a disc if the PlayStation 2 logo comes on and disappears in less than 3 seconds carefully replace all parts and your good to go.