There are a number of reasons why a DVD player may not be reading a disc. One of the most common reasons is that the disc may be dirty or scratched. If this is the case, try cleaning or repairing the disc.
Another reason a DVD player may not be reading a disc is if the player is not properly calibrated. To calibrate a DVD player, you will need to use a disc that has a calibration test pattern on it. There are a number of these discs available online.
If the DVD player is not reading a disc because …