Dvd tray will not stay closed. opens and...

i had exactly the same problem on a LG-RH278H resp. a Medion MD 81733. I solved it by opening the micoswitches, cleaning the contacts and streching the springs inside the switches a little. The Problem was, that one of the microswitches stayed conductive even when it was off/open.

I'm not familiar with your exact model, but usually when this happens, the loading belt is at fault. There are microswitches inside which determine the limits of the tray movement. There is one that is activated to indicate that the tray is out and another to indicate that the tray is in. If the belt slips, the inner may not be activated and the system will cause the tray to come out. Try replacing the belt.

Keep us posted.
Dan