LG TV line keeps restarting or will not stay on: LG's power guidance is reassuring about timing and specific about faults. It says a webOS TV normally takes about one to five seconds to turn on and display the screen, because it is recognizing input signals from the broadcast and external devices. If the power-on feels slow, check QuickStart+: when it is on, the power-on time is shorter, at the cost of higher standby power; switch it under All Settings, General, Additional Settings, QuickStart+.
The checks in more detail
If the webOS logo appears and then the screen, that means the software update has completed and there is no problem. LG advises contacting a service technician if the power standby indicator at the bottom flashes when the TV is turned on and then goes off, if you hear sound but the screen does not appear and pressing the menu or volume buttons on the TV remote shows nothing on screen, or if the screen does not appear after more than ten seconds. Use the TV remote, not the set-top box remote, when testing.
For a TV that turns on or off by itself, check Simplink (HDMI-CEC), which lets a connected device wake the TV, under All Settings, Connection, Device Connection Settings, Simplink, and turn it off to test; check Timer settings such as Sleep Timer, Timer Power Off and the Auto Power Off setting under All Settings, General, Timer; and check that the remote is not stuck. If the TV restarts in a loop, unplug it for a minute, disconnect every device and test with power only, since a faulty HDMI device can crash the TV.
Update the software. Note when the fault happens and what was running. A TV that restarts only when a soundbar or console is on has a device or HDMI-CEC cause, and a TV that restarts at a fixed time has a timer cause, and a written note of the pattern usually finds the answer without any parts. Keep a photo of the label showing the model and serial number, since service always asks for both and the label is hard to read once the TV is on a wall mount.
Differential
Likely causes of “LG TV line keeps restarting or will not stay on”, and how to tell them apart
- 1
A slow start with QuickStart+ off
What separates it The picture takes several seconds to show because QuickStart+ is switched off
How to confirm Turn QuickStart+ on if you want faster starts
- 2
A post-update start
What separates it The webOS logo shows before the picture because the TV has just finished an update
How to confirm This is normal after an update, and no fault is present, so wait a moment
- 3
Simplink waking the TV
What separates it The TV turns on by itself because Simplink lets a connected device wake it
How to confirm Turn Simplink off to test, and see whether the TV still turns on by itself
- 4
A timer setting
What separates it The TV turns itself off because a sleep timer or an off timer has been set
How to confirm Check the timers in the settings, and switch off any sleep or off timer that is set
- 5
A board fault
What separates it The standby light flashes and then goes off because of a fault on the board
How to confirm Contact LG service, since a flashing light that goes off points to a fault inside the TV
Before you touch a setting
Record this first — changing settings destroys the evidence
- What the standby indicator does when the TV will not start
- Whether menu or volume shows on screen
- Whether it happens after a device is turned on
- The model and the software version that the TV shows
Try in this order
0 of 7 completedUse the TV remote
ReversibleUse the TV remote and not the set top box remote, since the wrong remote will not switch it on.
Check QuickStart+
ReversibleCheck QuickStart+ in the settings, since it makes the TV start faster when it is turned on.
Turn off Simplink
ReversibleTurn off Simplink in the Device Connection Settings, if the TV wakes up by itself.
Check the timers
ReversibleCheck the sleep timer and the off timer in the settings, and switch off any that are set.
Unplug for a minute
ReversibleUnplug the TV for a minute with the other devices removed, then plug it in and test.
Update the software
ReversibleUpdate the software on the TV, if it starts, and then retest whether it restarts by itself.
Contact LG
ReversibleContact LG if the standby indicator flashes, since that points to a fault inside the TV.
Model-specific
What is true of this model and not of its siblings
- OLED
- OLED models include panel care routines that run after the TV is turned off, so a short delay or sound is normal.
- 2025 models
- The C5, G5 and B5 use webOS 25 with the same power settings.
- Other models this page answers
- These steps also fit models B3, B4, B5, C2, C3, C5, CX OLED TV, G3, G4, M4, QNED85T, QNED90T, UR9000.
Stop boundary
When this stops being a self-service repair
- !If the standby indicator flashes then goes off, contact LG service
- !If sound plays but the menu never shows, contact LG service
- !If the screen takes more than ten seconds every time, contact LG service
Evidence ledger
Sources behind this answer
QuickStart+ and the standby indicator.
Screen and Sound Self-Diagnosis by model year.
Software Update menu.
Menu test, HDMI, antenna and signal strength.
The company and its products.
Exact questions
Common questions
How long should an LG TV take to turn on?+
An LG TV should take about one to five seconds to turn on and show a picture.
What is QuickStart+?+
A setting that shortens power-on time.
What does the webOS logo mean?+
The webOS logo means that a software update has just completed, so it is normal.
Why does my TV turn on by itself?+
The TV can turn on by itself because of Simplink or a timer that has been set.
Where is Simplink?+
Simplink is in the Device Connection Settings, in the TV's menus.
Can a device crash the TV?+
Yes, a faulty HDMI device can.
Should I use the TV remote?+
Yes, use the TV remote, since a set top box remote may not switch the TV on.
How long is an LG TV warranty?+
It is a limited warranty from the date of purchase, so check your paperwork for the exact period.
What is webOS?+
webOS is LG's smart TV operating system, and it is updated by model year, so older models get fewer new features.
What is Simplink on an LG TV?+
Simplink is LG's name for HDMI-CEC, which lets the devices that are connected to the TV control each other.
What is the Magic Remote?+
The Magic Remote is LG's pointer remote, which has a scroll wheel and voice control built in.