I have not used the DVD player for a while. Last time I used it was for a CD to play a continuous loop music evening.
However, now I find that I can't open the DVD tray. I can't seem to see a "release" hole or key, and I can't see anything in the manual that says "hold this and that together for x seconds and the tray will open".
The problem is a small rubber belt underneath the DVD tray. This is the belt that couples the tray motor to the mechanics of the DVD tray. After a while the belt stretches and won't operate the DVD tray anymore. Solution is to remove the DVD mechanism and partially dissassemble it and replace the belt. I was lazy and used the one out of an old computer CD ROM drive!