[rgovostes]

A decade ago my LG plasma TV had a serial port for using it as digital signage (I think). If I spammed the serial port during boot I could interrupt U-Boot but they had disabled echoing out. I never figured out if I could do something useful or not.

[bigbaguette]

Serial ports on tv are usually for screen control, as in turn on/off, change input, set volume... Like what you can do with the OSD and the remote