What to Check First
- Forgotten Knock Code?
- To reduce battery consumption and prevent unintended knocks, G4 is designed to sense the knocking gesture anywhere on the screen, but preferably in the area on the center of the screen.
- If the phone is moved when you knock on the screen, the knocking gesture might not be sensed. e.g. Knocking the screen with your thumb while holding the phone in your hand.
- You should double-tap with a fingertip, not with a nail, to wake the display or put it to sleep.
- Knock On feature cannot be disabled.
- You can setup a backup PIN in case you forget your knock code sequence.
- From the Home screen, tap Apps > Settings > Display tab > Lock screen.
- Tap Select screen lock > Knock Code .
- Read the tutorial and tap the NEXT button.
- Tap 3-8 times in the 2X2 grid shown to set your knock code. Then tap the CONTINUE button.
Why This Can Happen
Symptoms can have more than one cause, and the correct steps depend on the exact model, installation and operating conditions. Use the checks above to narrow the issue before service.
Safety and Model-Specific Guidance
Stop troubleshooting if you notice burning, electrical damage, unsafe heat, gas odor, refrigerant concerns, or water near electrical components. Follow the official LG USA instructions for your exact model.
Frequently Asked Questions
What should I check first for LG Mobile Phone - G4 Knock ON™ & Knock Code™?
Forgotten Knock Code?
When should I stop troubleshooting and contact LG?
Stop if the product shows signs of electrical damage, burning, leaking near electrical components, or if the recommended checks do not resolve the issue. Use LG USA support for model-specific service guidance.
Does this guidance apply to every LG model?
Not always. Controls, error codes and service steps can differ by model. Confirm the exact model number and follow the linked LG USA article for model-specific instructions.
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