My xbox 360 BEN-Q drive has recently stopped

My xbox 360 BEN-Q drive has recently stopped working. I have tried EVERYTHING possible (POT Tweak, Cleaning the laser with alcohol,cleaning the entire xbox, making sure magnets are align). The laser still works fine at the reading of 3.02 ohms and it lights up, so it isn't dead. It also reads CD's fine but DVD and Games do not work. I know that they are seperate pots, so have I messed up the pots? Any help is appreciated, I don't want to buy a new xbox yet. Thanks in advance