An LG TV that turns on or off by itself is usually reacting to a setting or connected device. SimpLink, timers, remotes, voice routines, and eco power features can all send power commands without anyone touching the TV.
These steps apply to LG smart TVs running webOS, including OLED, NanoCell, QNED, and UHD models.
Does this affect you?
Use this if the TV powers on by itself, shuts off during viewing, or seems to follow another HDMI device’s power state unexpectedly.
Check SimpLink HDMI-CEC
- Open Settings > All Settings > General.
- Find SimpLink (HDMI-CEC). On newer webOS versions, check Devices > External Devices or External Device Manager.
- Open SimpLink settings.
- Turn off Auto Power Sync or similar options if available.
- Disable SimpLink completely as a test.
- Check connected devices, soundbars, consoles, and streaming boxes for their own CEC or TV-control settings.
HDMI-CEC is convenient when it works, but it is the most common cause of a TV that turns on or off with another device.
Check sleep timer and schedules
- Open Settings > All Settings > General > Timers.
- Check On Timer and Off Timer.
- Disable any schedule that matches the unwanted power behavior.
- Check Sleep Timer and set it to Off if it was enabled.
Sleep Timer is a countdown. On/Off Timer schedules repeat at specific clock times. If the TV shuts off at the same time every day, look for a schedule, not a random fault.
Rule out the remote
- Remove batteries from the LG Magic Remote.
- Wait about a minute and observe whether the power behavior stops.
- Check for a stuck power button.
- Install fresh batteries and test again.
- Also remove or disable universal remotes, cable-box remotes, and HDMI-CEC control from other remotes while testing.
A stuck button or weak remote battery can send repeated power commands that look like the TV is acting alone.
Check updates, eco standby, and power quality
Install updates from Settings > All Settings > General > About This TV > Check for Updates. LG sometimes fixes power behavior bugs through webOS updates.
Under General > Eco, look for automatic standby, no-signal power off, or energy-saving power options. These can shut the TV off during pauses or quiet viewing.
If the TV powers on after storms or power flickers, use a surge protector and note the pattern for LG support. If SimpLink, timers, remotes, updates, and eco settings are ruled out, a failing power button or control board may need service.
Sources
- LG Support – TV turns on or off by itself (2025)
- LG Support – SimpLink (HDMI-CEC) settings guide (2025)
- LG Support – Sleep and on/off timer settings (2025)