HDMI-CEC can allow connected devices to control TV power, which may cause unexpected power on or off behavior.
Turn off SIMPLINK (HDMI-CEC) in the TV’s HDMI settings to stop external devices from controlling power.
HDMI cables can support CEC, which allows power control between connected products.
If CEC malfunctions or an external device sends a power command, the TV may turn on or off by itself.
When SIMPLINK (HDMI-CEC) is enabled, connected devices (sound bar, set-top box, Blu-ray player, etc.) can send power commands to the TV.
This can result in the TV turning on or off unexpectedly.
Some external devices have their own power synchronization or automatic standby features.
These features can trigger TV power changes through HDMI-CEC.
Disable SIMPLINK (HDMI-CEC) in the TV’s HDMI settings.
If the issue continues, also disable power synchronization or automatic standby features on the connected external device.
Setting: General > External Devices > HDMI Settings > SimpLink (HDMI > CEC)
Press the Settings button on the remote.
Select All Settings.
Go to General, then External Devices.
Open HDMI Settings.
Set SimpLink (HDMI-CEC) to Off.
On your set-top box or other HDMI device, turn off TV power synchronization and any automatic power standby features.
If you are not sure where these options are, contact the device manufacturer or service provider for detailed steps.
Check whether the TV software/firmware is up to date.
If the problem continues, service diagnosis may be required.
This can include power synchronization and controlling connected devices with the TV remote.
Turn off power synchronization and automatic standby options on the external device as well.
If the steps above did not resolve your issue, please visit the LG Electronics Support website. You can chat with our virtual assistant or schedule a service repair for further assistance.
※ Please note that service fees may apply for engineer visits if your product is out of warranty.
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