After much experimenting, I believe that the problem has something to do with my discrete "off" code for this DVD player. When I use the setup code 0490 with the discrete "off" code 026 to turn my DVD player off, this works, but then when I subsequently turn the DVD player on (whether I use a discrete code to do so or not)the DVD LCD screen displays "WELCOME TO DVD WORLD" then "CLOSE" (instead of "WELCOME TO DVD WORLD" then "NO DISC"). When this occurs, if I try to open the tray by hitting eject, the LCD screen just toggles between "OPEN" and "CLOSE" when I hit eject without any movement of the tray.
The discrete "on" code (0490 - 022) appears to work fine. I can always turn the DVD player on successfully using this code as long as I have used the remote power button to turn the DVD player off beforehand. If I use the discrete "off" code to turn the DVD player off, I get that "CLOSE" message when I turn the DVD player on again whether or not I use a discrete code to turn the DVD player on.
This is very frustrating and I wonder if anyone else has had this problem with the Panasonic RP-56. I suppose I could just leave the DVD player on all the time but I'd rather find a discrete "off" code that doesn't screw the player up.
