We have a Samsung PS-63P71FH 63 inch plasma TV in the lobby at work. TV Spec page https://www.samsung.com/nz/support/model/PS63P71FHX/RAD/
We recently in the last month moved our Raspberry Pi running Yodeck over to this TV from a portable TV that worked fine with HDMI-CEC commands.
Problem is that the HDMI-CEC command to turn off the TV fails and then TV stays on all night displaying no signal on HDMI 3. All other HDMI-CEC functions like Turning on the TV and Switching Input works fine as the Raspberry PI happily sends these commands to the TV.
I have tried different HDMI ports to no avail. Switching to a different HDMI Port in the long term is not an option as most of the ports are located at the back of the TV and the bracket does not have a lot of room behind it hence why we use HDMI 3 located on the side of the TV.