This can happen if the video format on the DVD player is set to an unsupported format.
The formats supported by your TV are:
1080p, 1080i, 720p, 480p, 480i
If the DVD player is set to a different format than those mentioned above, then your TV set may not be capable of reading the signals.
Test the DVD player on a different TV set, and check what format it is set to. Adjust if necessary.