LG TV Turns On by Itself? Check the Timer and SIMPLINK (HDMI-CEC)
When an LG TV turns on by itself with no other visible issue, LG names two settings-side causes: the Power On Timer, or a connected HDMI device waking the TV through SIMPLINK (HDMI-CEC). If neither is it, LG's next steps are a software update and a full power cycle, then service.
Quick answer
LG traces a TV that turns on by itself to two settings: the Power On Timer is switched on, or a connected HDMI device wakes the TV through SIMPLINK (HDMI-CEC). Turn the timer off first, then turn SIMPLINK off on the TV and on the connected device.
- 1.Open Settings → All Settings → General → System → Time & Timer → Timers and make sure the Power On Timer is Off (2021 and 2022 models; older paths are listed below).
- 2.Turn off SIMPLINK: All Settings → General → Devices → HDMI Settings → Simplink (HDMI-CEC) → Off, and disable HDMI-CEC on the connected device too.
What it means
LG's own help article for this symptom says that when an LG TV turns on automatically with no other visible issue, the cause can be the TV's timer settings or an external device connected to it. In other words, something is telling the TV to switch on.
The two senders are easy to tell apart. The Power On Timer switches the TV on (or off) at the specific time that was set, so a timer shows up as the TV waking at the same time each day. SIMPLINK, LG's name for HDMI-CEC, lets connected HDMI devices control power between products: with it active, the TV powers on when a connected HDMI device is switched on, or when that device is in standby and wakes for automatic updating. That second case can explain a TV coming on in the middle of the night.
If neither setting is the cause, LG suggests the TV may not be on the latest firmware and should be updated to remove bugs, followed by a full power cycle. If the problem continues after that, LG says service is required.
Common causes
- Power On Timer switched on. This option sets the TV to power on or off at a specific time. If it is on, the TV wakes up at that time whether anyone is watching or not.
- SIMPLINK (HDMI-CEC) waking the TV. With SIMPLINK active, the TV powers on when a connected HDMI device is activated, or when that device is in standby mode for automatic updating.
- HDMI-CEC still active on the connected device. LG notes that the feature also needs to be disabled on the connected HDMI device. Turning it off on the TV alone may not be enough.
- Outdated TV firmware. If it is not a setting issue, LG says the TV may not be on the latest firmware and needs an update to remove bugs.
- Fault that needs service. If the TV keeps turning on after the timer, SIMPLINK, update and power cycle steps, LG says service is required.
Before you start
- Note when it happens. If the TV turns on at the same time every day, start with the timer. If it turns on at random times, start with SIMPLINK.
- List what is plugged into the TV's HDMI ports (for example a set-top box, game console or soundbar). Any of them can wake the TV through HDMI-CEC.
- Check whether the TV switches on when one of those devices is turned on. If it does, the HDMI-CEC link is doing it.
Fixes, from safest to last resort
Turn off the Power On Timer
No data loss- 1On the remote, open Settings and select All Settings.
- 22021 (webOS 6.0) and 2022 (webOS 22) models: go to General → System → Time & Timer → Timers. 2020 (webOS 5.0): General → System → Time → Timers. 2019 (webOS 4.5) and earlier: General → Timers.
- 3Select Power On Timer. If it is On, toggle it to Off.
Only the timer changes; nothing else on the TV is reset. On NetCast TVs the option is under Settings → Time → Power On Time / Power Off Time.
Power cycle the TV
No data loss- 1Turn off the TV and unplug it from the wall.
- 2Press and hold the power button on the TV itself for 30 seconds. Its location varies by model.
- 3Keep the TV switched off for 5 minutes.
- 4Plug the TV back in and switch it on.
This is the final step in LG's troubleshooting for this symptom. It changes no settings, so it does no harm to do it early.
Turn off SIMPLINK (HDMI-CEC) on the TV and the connected device
Re-setup needed- 1On the remote, open Settings and select All Settings.
- 22021 (webOS 6.0) and 2022 (webOS 22) models: go to General → Devices → HDMI Settings → Simplink (HDMI-CEC) and set it to Off.
- 32020 (webOS 5.0): Connection → Device Connection Settings → Simplink (HDMI-CEC) → Off. 2019 (webOS 4.5): Connection → HDMI Device Settings → Simplink (HDMI-CEC) → Off. 2019 (webOS 4.0) or earlier: General → Simplink (HDMI-CEC) → Off.
- 4Disable the HDMI-CEC function on the connected HDMI device as well, using that device's own settings menu.
SIMPLINK lets devices share power control, so with it off, switching on a connected device will no longer turn the TV on. LG notes the feature also has to be disabled on the connected device.
Update the TV software
Re-setup needed- 1On the remote, open Settings and select All Settings.
- 22020 (webOS 5.0) or later: go to Support → Software Update → Check for Updates. 2019 (webOS 4.5): General → About This TV → Check for Updates.
- 3Install any update that is offered and let the TV restart.
LG recommends this when the cause is not a setting: the TV may not be on the latest firmware and the update removes bugs.
If a menu doesn't match your TV
- LG's article gives menu paths for models from 2019 (webOS 4.0) to 2022 (webOS 22) plus NetCast. On a newer TV the path may be different; look for the same menu names: Timers, HDMI Settings and Simplink (HDMI-CEC).
- On NetCast TVs the timer lives under Settings → Time, split into Power On Time and Power Off Time.
- Each brand of set-top box, console or soundbar names HDMI-CEC differently in its own menu. Check that device's manual for where to turn it off.
- Using a Samsung TV instead? See our guide on a Samsung TV that turns on by itself.
When to contact support
LG says that if the TV keeps turning on after these steps, service is required, and it points to its Request a Repair page. Before you contact LG:
- Have the TV's model number ready.
- Tell them which steps you already did: Power On Timer off, SIMPLINK off on the TV and on the connected device, software update and the 5-minute power cycle.
- Mention when the TV turns on (a fixed time or random times) and which HDMI devices are connected.
Sources
- Official source: LG USA Support: LG TV - Why Does My TV Turn On By Itself · www.lg.com
- Official source: LG USA Support: LG TV - Why Does My TV Turn On By Itself (alternate help library URL) · www.lg.com
Frequently asked questions
Why does my LG TV keep turning on by itself?+
LG lists two settings behind it: the Power On Timer, which switches the TV on at a set time, and SIMPLINK (HDMI-CEC), which lets a connected HDMI device power the TV on. Turn off the timer, then turn off SIMPLINK on the TV and HDMI-CEC on the connected device.
Why does my LG TV turn on by itself in the middle of the night?+
Two causes fit a night-time wake-up. A Power On Timer set to that hour turns the TV on at the same time each night. With SIMPLINK on, a connected HDMI device that is in standby and wakes for automatic updating can also switch the TV on. Check the timer first, then SIMPLINK.
Do I have to turn off HDMI-CEC on the connected device too?+
Yes. LG notes that the feature also needs to be disabled on the connected HDMI device, not only on the TV. Look for the HDMI-CEC option in that device's own settings.
What do I lose if I turn off SIMPLINK on my LG TV?+
SIMPLINK is the power control link between the TV and its HDMI devices. With it off, turning on a connected device no longer turns the TV on, so you switch the TV on with its own remote.
LG TV keeps turning off at the same time every day: is it the same setting?+
It can be. LG's timer option sets the TV to power on or off at a specific time, and NetCast TVs list a separate Power Off Time. Open the Timers menu (or Time on NetCast) and check for an off timer you did not set.
Does an LG TV turning on by itself mean it is broken?+
Not necessarily. LG first points to timer settings and connected devices, then to a software update for bugs. Only if the TV keeps turning on after the timer, SIMPLINK, update and power cycle steps does LG say it needs service.
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