Lines across your TV picture can be caused by something as simple as a loose HDMI cable, or by a fault in the screen itself. A few quick checks will usually tell you which one you’re dealing with.
Safety first: Never open a TV yourself. Parts inside a TV can hold a dangerous electrical charge even after it has been unplugged. Only try the checks from the outside of the TV described here.
Moving lines or lines that stay put?
Watch the lines for a minute:
- Lines that flicker, move or come and go are often linked to the signal: the cable, the device you’re watching or the input it’s connected to.
- Lines that stay in exactly the same place, whatever you watch, are more likely to come from the screen panel or the parts that drive it.
This isn’t a rule for every TV, but it’s a useful starting point.
Safe checks to try
1. Open the TV’s own menu
Press the Menu, Home or Settings button on the remote. The menu is drawn by the TV itself, not by your decoder or streaming device.
- Lines on the menu too: the problem is most likely inside the TV.
- The menu looks clean: the problem is more likely the cable, the input or the connected device.
2. Run the built-in picture test, if your TV has one
Many TVs have a picture test in their support or self-diagnosis settings. On recent Samsung TVs, for example, it’s under Settings › Support › Device Care › Self Diagnosis › Picture Test, though the path depends on the model. If the lines show up in the test picture, the TV itself needs attention.
3. Reseat or swap the HDMI cable
Unplug the HDMI cable at both ends and plug it back in firmly. If you have a spare cable, try it, or plug the device into a different HDMI port on the TV.
4. Try a different source
Switch to another input, a built-in app or a different device. If the lines only appear with one decoder, console or streaming box, that device or its cable is the likely cause.
5. Restart and update
Switch the TV off at the wall, unplug it for 60 seconds, then switch it on again. If your TV is connected to the internet, check for a software update in its settings.
When to stop and call a technician
- The lines appear on the TV’s own menu or in the picture test.
- The lines appeared after the TV was knocked, dropped or pressed.
- You can see a crack, a dark patch or a spreading mark on the screen.
- The lines are getting worse, or the picture keeps cutting out.
Don’t press on the screen to see if the lines change. LCD and OLED panels are fragile and pressure can cause more damage.
What a technician will look at
Lines that start inside the TV are usually linked to one of these:
- The connection between the panel and the TV’s boards, such as a loose or damaged ribbon cable.
- The T-con board, which controls the picture on the panel.
- The main board, if the problem appears on every input.
- The panel itself, if it has been damaged.
Only a technician who inspects the TV can confirm the cause. Panel damage can be expensive to repair, so ask for a quote and read should you repair or replace your TV? before you decide.
Still seeing lines?
Use the Problem Finder for a quick check, or send a repair request with your TV details.