Can anyone elaborate on the correct settings needed for RS232 control? I'm 90% sure I have everything set correctly yet I experienced the same issue as Krassyg. Everything worked fine controlling my XBR75X850E from an Extron MLC controller for about a month and now the TV doesn't respond at all.

I've been reading that the Sony RS232 ports only work intermittently. Even tech support at Extron said they had a rough time getting it to work. They said sometimes the RS232 port took commands and sometimes it didn't.