We have used these TV's a lot and controlled them via serial and IP many times with the module in the application marketplace.? I would recommend you use a multimeter to pinout the DB9 cable and figure out what color wire is being used for 2, 3, and 5 and then you can land them on the processor. If it doesn't work, then try flipping the TX and RX on the processor.??
I believe with the modules you have to turn off low power mode and the display has to be on initially for the module to initialize.??
