My ps2 has stopped playing dvdrs. i have it modded with a neo 4.1 and it use to boot up dvdrs no problem with the devil may cry demo or the gameshark but now it wont. if the mod chip is messed up would i be able to uninstall it and install a new one? could someone help me out

Can you boot original dvd's (game or movies)? If you can't then you you dvd laser is gone and you might need a new laser assembly. You can verify that it's your dvd laser if it still boots cdr's originals and backups.

Try to take out the chip and see if it works.

dvd movies and cdr backups still work and i have tried cleaning the lens.