Rear Overhead DVD Entertainment System Help

[otherones]

New (to me) X5 owner here. Three weeks ago I purchased a 04 X5 that has the rear overhead DVD system installed.

I am having trouble figuring out how to use the DVD player and am hoping someone here may have some experience.

I can get the overhead monitor (just to the rear of the sunroof) to turn on and can cycle through AUX, Video 1, Video 2 sources.

I cannot, however, seem to get the DVD player itself to power / accept a disc insert.

The dvd player itself is in a trunk panel (can provide pictures if needed).

Anyone familiar with the system that can give me some troubleshooting pointers? The manual is not very helpful.