If your disk drive isnt reading games, isnt opening, throws out open tray error or play dvd when a game is inside here are something you can try that have worked for me time and time again

1. Take the Xbox apart
2. Take the disk drive apart
3. Remove all the dust from the disk drive (blow it out, i recommend using a brush)
4. Get rubbing alcohol and a Q-tip, put a little bit of rubbing alcohol on the Q-tip and gently polish the laser lens
5. Get some sort of lubricant or Vaseline and rub some on the rails, gears, sliding mechanism (dont over do it but put a generous amount and rub it in)
6. Replace the disk drive belt (it is the black rubber band in the disk drive can be purchased for cheap; sometimes taking it off and cleaning it with water will be enough!)


These steps should fix almost any disk drive problem you will encounter besides having to replace whole components!