46" 2010 Samsung Smart TV.
In May 2017 after a power outage, all HDMI ports recognized there was something plugged in but couldn't read the signals from those boxes. So I did a factory reset listed in an earlier post. For my television this worked:
Power off television and unplugged for 10 minutes.
Disconnected the Roku and the Blu-Ray
Pressed Mute, 1, 8, 2, Power (on the remote -- in that order)
Television turned on with Factory Reset screen
Chose "Option"
Chose "Factory Reset"
The television automatically turned itself off.
Pressed "Power"
Television turned on with the original set-up menu.
Plugged in each of the devices and HDMI ports worked as if it were new.