I've interpreted your post as saying that the particular game, the one you play heavily, doesn't boot now. There is a utility called CDcheck.exe that will check the condition of the particular game. if it has errors, then you're stuffed. The utility can be loaded from ####://www.cdrinfo.com/software/

When I first read your post I thought it was all PS2 games so I suspected damagae from one of the non-modchip methods; obviously not the case.