I had controlled dozens of Panasonic plasma over the years by RS-232 without a single issue. Today I couldn't control a 103" set. I tried everything possible. First I checked with a terminal program that the set was receiving the right strings from the Crestron system. Second I swapped the Rx and Tx cables just to make sure they were not in null modem. Then I tried connecting from my laptop with a terminal program to the set and tried unsuccessfully to get the set to respond. I check the Menu on the plasma to make sure that the TV didn't have the communications port off, even when I already did one of this 103 about a year ago and didn't find any issues with it. Last I called Panasonic Tech Support to a number that I had called before several times with good results, to find out that my call was routed to someone in India that didn't have a clue what RS232 was and transferred me to the Panasonic Hot Line (I hanged up right there). I double checked the protocol to make sure that nothing had changed in the protocol communication settings for this TV, and it was exactly as I was expecting. I don't have any other thing to think than the port is dead, unless that there is a hidden menu to activated the port; but again we did one about a year ago and we didn't have to do anything extra.
I'm posting this here with the hope that someone might know something that I'm not aware of (by the way all the power management settings on the TV are turned off).
When we can't control a device by RS232, we usually stick an emitter inside but there is not way to lay down this 500lbs beast on the floor to do that. I guess if by tomorrow morning I haven't found a possible solution I would have to stick an emitter at the front of the IR receiver and hang it on the wall (yuk).

Pedro

Give me a call. I will put you in touch with the right guy to fix your problem.

I called you but I got the voice mail. If when you call me you can't reach me, send me the info a [email protected].