Chosen Solution
I own the 2005 white xbox 360. I put halo reach in, it says open disc tray. I put downton abbey dvd series in, all of them read “open disc tray”. Then i put a burned copy of iron man 2 in, and it works perfectly. I put in cd’s and they all play their music perfectly. What is wrong with my xbox? It only reads burned dvds and not official games or dvd’s. Granted, i only own one game for the 360-halo reach.
gotkeys2open24 sounds like a bad/dirt laser assembly. You can try and clean it with a commercially available cleaner. You can also either replace the laser assembly or the complete drive. The drive is mated to the motherboard so you will need a drive key. Use this guide to replace it or even better purchase the paired set from here Update (06/18/2016) Here are the instructions for the Pot calibration. See if that will temporarily work for you. XBOX_360_POT_CALIBRATION.pdf
