how to fix ps3 disc not reading ( without opening the ps3) (HD QUALITY)

ANY QUSTIONS www.youtube.com/DARRENLAAD1 - MY PS3 WASNT PLAYING BLU RAYS BUT EVERY THING ELSE SO PUT YOUR DISC IN LOAD UP A DEMO AND THEN HIT PLAY STATION BUTTON AND YOUR SEE THAT YOUR GAMES THEIR ! IF THIS WORKS FOR IT MEANS YOUR LENS WILL NEED CLEANED JUST BUY A SPECIAL BLU CLEANER