We are pretty sure we found the problem with RS232 and Sony tvs. We found that you have to be signed into a google account on the Android system in order for apps to update. It turns out EVERYTHING is an app including rs232 and input control etc. After signing in to the Android system the problematic tv starting working on rs232 again. Since then I found 2 other Sony tvs that lost video on one input and after signing in and turning on auto app updates the input started working again. Thanks for the help on this.