I have a Sony 84 in TV. I am using an external ROKU device. The device can work for hours with no trouble then the TV can completely go black and no sound for 1 to 3 seconds. It could do this 3 to 5 times in 5 minutes. Then the TV will run perfectly for up to an hour. It may be that the ROKU device may be resetting? I have tried pulling the power plug on the ROKU device but to no avail. The TV shows that the ROKU device is a recognized input. Has any one seen this before?
We would recommend performing these troubleshooting steps and see if they will resolve the issue you're experiencing.
The video cable is not connected properly or the cable is faulty
Check that the video cable is firmly connected to the back of your Roku player and to the HDMI or composite connector on the TV. If you have a Roku Streaming Stick, then make sure it is firmly connected to the HDMI connector on your TV.
If you can, check to see if you have a faulty cable by connecting your Roku player with a different cable.
There is a problem with the TV
If you can, try connecting the Roku player to a different input on the TV to see if the problem is with the connector on the TV.
If you can, try connecting the Roku player to a different television to see if the problem is with your Roku player or the TV.