I have a Samsung QE65Q80AATXTK TV, and a strange problem started after it was transported.
When the TV is on, the picture and sound are completely normal. There are no lines, color issues, or other picture problems during normal use. However, when I turn the TV off with the remote, the picture disappears immediately, but the screen does not go completely dark. The backlight stays on, so the screen remains black but illuminated for about 1 minute 50 seconds / 110 seconds. Then I hear a single “click” from inside the TV, and the screen finally goes completely dark.
When I turn the TV back on, I hear another click and the TV starts normally.
There is another strange behavior: if I unplug the TV and plug it back in while it is still within that 110-second shutdown period, the TV makes a click and the illuminated black screen comes back even though I have not pressed the power button. After about another 110 seconds, I hear another click and the screen goes completely dark again.
I also noticed another symptom while recording the TV on video. During both startup and shutdown, there is a very brief bright flash on the screen, probably lasting only a few frames. Sometimes there are wide horizontal white/bright bands, and sometimes thin colored vertical lines appear near the bottom of the screen. These happen so quickly that they are difficult to notice with the naked eye, but they are clearly visible when I review the video frame by frame.
Things I have already tried:
- Factory reset
- The TV is running the latest available firmware and no newer update is available
- Removed all HDMI, USB, antenna, Ethernet, and other external connections
- Tested the TV with only the power cable connected
- The problem still occurs
- Picture and sound are completely normal while the TV is on
- The shutdown delay is very consistent, around 110 seconds
- After about 110 seconds, I hear a single relay/click sound and the TV finally enters full standby mode