If lines, dots, or spots appear on your LG TV screen, the issue may be with the broadcast signal or a connected cable.
Use Screen Self-Diagnosis to quickly determine whether the issue is with the TV.
Set the aspect ratio to 16:9 or Original, and check the HDMI cable connection.
Why Do Lines or Dots Appear on the TV Screen?
- There may be a temporary issue with the video signal from an external device, such as a set-top box.
- A loose or damaged HDMI or antenna cable may cause visual noise.
- An incorrect aspect ratio setting may cause lines to appear along the edges of the screen.
- A connected external device may not support HDMI Deep Color, which can cause visual noise or display issues.
- There may be an issue with the TV.
How to Fix Lines or Dots on Your TV Screen
Step 1. Run Screen Self-Diagnosis
How to check your TV's webOS version
On your TV remote, press the Settings (gear icon) or Mute button three times in a row.
- Use Screen Self-Diagnosis to determine whether the issue is with the TV or a connected external device, such as a set-top box.
- If the test image appears normal, check the HDMI cable connection, the external device settings, and whether the external device is working properly.
- If the lines or dots also appear in the test image, your TV may need to be inspected.
- TVs Released in 2021 or Later (webOS 6.0 or Later): Press the Settings button on your remote. On the TV screen, select All Settings, Support, and Screen Self-Diagnosis in order.
- TVs Released in 2020 (webOS 5.0): Press the Settings button on your remote. On the TV screen, select All Settings, Support, Additional Settings, and Picture Test in order.
- TVs Released in 2019 or Earlier (webOS 4.5 or Earlier): Press the Settings button on your remote. On the TV screen, select All Settings, Picture, and Picture Test in order.
Step 2. Check the Antenna and HDMI Cable Connections
Turn off your TV and disconnect the antenna and HDMI cables. Check the cables and ports for dust or damage, then reconnect each cable securely. If the issue continues, try a spare cable to determine whether the original cable is damaged.
Step 3. Change the Aspect Ratio
- An incorrect aspect ratio setting may distort the picture or cause lines to appear along the edges of your screen. Set the aspect ratio to 16:9 or Original. Follow the steps for your TV’s release year and webOS version:
- TVs Released in 2021 or Later (webOS 6.0 or Later): Press the Settings button on your remote. On the TV screen, select All Settings, Picture, Aspect Ratio, User Selection, and then 16:9 or Original.
- TVs Released in 2020 or Earlier (webOS 5.0 or Earlier): Press the Settings button on your remote. On the TV screen, select All Settings, Picture, Aspect Ratio Settings, Aspect Ratio, and then 16:9 or Original.
Step 4. Turn Off HDMI Deep Color
- If a connected external device does not support HDMI Deep Color, lines, flickering, or color distortion may appear on your screen. Follow the steps for your TV’s release year and webOS version:
- TVs Released in 2026 or Later (webOS 26 or Later): Press the Settings button on your remote. On the TV screen, select All Settings, System, External Devices, HDMI Settings, and HDMI Deep Color. Turn off the setting for the affected HDMI input.
- TVs Released from 2021 Through 2025 (webOS 6.0 or Later): Press the Settings button on your remote. On the TV screen, select All Settings, General, External Devices, HDMI Settings, and HDMI Deep Color. Turn off the setting for the affected HDMI input.
- TVs Released in 2020 or Earlier (webOS 5.0 or Earlier): Press the Settings button on your remote. On the TV screen, select All Settings, Picture, Additional Settings, and HDMI Ultra HD Deep Color. Turn off the setting for the affected HDMI input.
Step 5. Still need help?
If the issue persists after following the steps above, you can get further support through LG Chatbot on our website or by requesting a technician visit.
FAQ
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Q. Why Should I Turn Off HDMI Deep Color?
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A. If a connected external device does not support HDMI Deep Color, turning on this setting may cause lines, flickering, or color distortion on the screen.
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This guide is based on standard models. The settings menu may vary by model.
