CM500xx is part of the LCD model number, it helps but in fact is not the board ID. You need to pull the PCB out and search for a white text line written somewhere in it. Its better if you not rely on apparently similar devices, but on your own player ID instead.
To bring the board out start by pulling up the side opposite to connectors, then moving pcb to the right to free it from the metal. The LCD may be glued to case, put gently a bit of force and the whole pcb+lcd will come out...
btw. that player is relatively easy to recover
