Well it could be "MEDia" instead of "MEDical" but who knows...
I was able to whip up a connector for the addressable interface using two Dymo label printer serial cords and a null modem - I did verify it was a straight connection for all six conductors. Then I powered it up with the board connected to the TV. I could still power the TV up with the remote, but there was no audio or video. I think this is as far as I can get without whatever is supposed to connect to the Keyboard port; that probably contained the power switch.
Next I think I will get the TV out of institutional mode, there is plenty of information out there on how to do that.