There are quite a few things that can cause a disc read error on the
slim PS2. The most frequent is a bad laser, however, here is some
useful troubleshooting info:
1. "Lid Closed Sensors" There are two "lid closed sensors" in the slim PS2. In a fall, it's possible that one or both have become damaged. Remove the top of the PS2 and try depressing both sensors with a game inside. The laser should move up and down at least???
IF YES, try again with the lid on... if the laser doesn't move when you close the lid, then the top casing of your PS2 cracked in the fall and is no longer depressing the lid closed sensors.
==> If the laser moves up and down OK but does not read discs, your laser was damaged in the fall. See below for a website with more troubleshooting info, pictures, and replacement cases and lasers.http://store.richspsxparts.com/slpsnospdi1a.html
IF NO, you have a bad lid closed sensor -- these are not really replaceable easily -- you may be better off replacing the whole PS2 if one or both of these lid closed sensors goes bad.http://store.richspsxparts.com/slpsnospdi1a.html