I have a Samsung UE40ES6540 with a very odd fault. After about 10 minutes of operation it stop responding to any controls - either the remote control or the button on the rear. When a remote button is pressed, the IR receiver light flashes, but the TV does not respond the stand-by, channel change, volume or any other controls.
The picture and sound is fine - I just can't change channel or turn it off (unless I pull out the power).
I have swapped out the main control board, performed factory resets and updated the firmware. I have also swapped out the wifi module and tried the TV connected via ethernet, but nothing makes any difference.
Any thoughts on how I can diagnose the fault would be appreciated.