i ripped Grand Turismo 4 to a DL+....wen i leave it 1 day off it plays but freezes for 2-3 mins...continues then to freeze

hey everyone i got my fan and hooked it up but i still have problems, i would load up a game through the browser and it would only bring me right back to the browser screen. so i twisted the dvd screw slightly to the right (under the laser) and now i get the ps2 logo but a solid black screen. do i need to just keep messin around untill it works? or is it something else

christ! this is not looking good. after adjusting the laser a few times i put everything back together and now it doesnt even power up!!!!