TV Has Lines on the Screen? Checks Before Repair

Horizontal or vertical lines across a television screen can look like a failed display panel, but the television itself is not always responsible. A connected device, damaged HDMI cable, reception problem, software error or incorrect source signal can produce similar symptoms.

Work through the checks below before arranging a repair. The most important first step is determining whether the lines appear in the television’s own menus or only while using a particular channel, application or connected device.

Check whether the lines belong to the TV or the source

Open the television’s Home, Settings or input menu while the lines are visible.

If the lines appear over the television’s menus, the problem is more likely to be inside the television.
If the menus look normal, but the lines appear on one device or input, investigate that source and its connection first.
If the lines appear only on one channel, the broadcast or antenna signal may be responsible.
If the lines appear in one streaming application, test another application before changing the television’s settings.

Change between free-to-air television, streaming applications and each connected HDMI device. This comparison can quickly show whether the fault follows one source or remains on every screen.

Run the television’s built-in picture test

Many televisions include a diagnostic picture test. Its location varies by brand and model, but it is commonly found under Settings, Support, Device Care, Self Diagnosis or Picture Test.

Run the test with external devices disconnected if possible.

If the test image is clear, the television’s display may be functioning correctly. Check the source device, signal and cables.
If the lines appear in the test image, the television itself is more likely to require further diagnosis or repair.

Samsung Australia similarly advises that a clean Picture Test points towards connected equipment or signal problems, while a fault visible in the test may require support.

Restart the television safely

A complete power restart can clear temporary picture-processing and software errors.

Turn the television off.
Disconnect it from the wall outlet.
Disconnect HDMI, USB and antenna connections.
Wait approximately two minutes.
Reconnect only the television’s power cable.
Turn it on and inspect the Home or Settings menu before reconnecting other equipment.

If the lines disappear while external devices are disconnected, reconnect them one at a time. Test the picture after connecting each device so you can identify which connection causes the problem to return.

Check HDMI cables and connected devices

If the lines appear only when using a game console, streaming box, receiver or other HDMI device, check the complete connection rather than assuming the screen is faulty.

Turn both the television and connected device off.
Remove and firmly reconnect both ends of the HDMI cable.
Try a different HDMI input on the television.
Test with another known-working HDMI cable.
Connect the device directly to the television if it normally passes through a receiver or soundbar.
Test another device on the same television input.
Check whether the source device is using a resolution and refresh rate supported by the television.

If changing the cable or input removes the lines, the television panel probably does not need replacing.

Check antenna and free-to-air reception

Lines or picture breakup that occur only on free-to-air television may be caused by the broadcast signal, antenna system or coaxial cable.

Change to several different channels.
Check whether other televisions connected to the same antenna have the same problem.
Firmly reconnect the antenna cable.
Inspect accessible cables for loose plugs, sharp bends or visible damage.
Run a channel scan if channels have recently changed or disappeared.

If only one channel is affected, the source broadcast may be responsible. If every free-to-air channel is affected but applications and HDMI devices look normal, the antenna system deserves attention.

Update the television’s software

Manufacturers sometimes correct picture-processing and compatibility problems through software updates.

Connect the television to the internet and check its Support, System or About menu for available updates. Keep the television connected to power while an update is installing.

After updating, restart the television and check the same sources again.

Reset the picture settings

An unusual picture setting normally affects colour, brightness or sharpness rather than creating permanent lines. However, resetting the picture mode is a safe step before performing a complete factory reset.

Look for an option such as Reset Picture, Reset Picture Mode or Restore Picture Defaults.

A factory reset should generally be a later step because it can remove:

Wi-Fi information.
Application logins.
Channel settings.
Accessibility preferences.
Custom picture and sound settings.

If you perform a factory reset, record any important settings first and follow the instructions for your exact television model.

Look for signs of physical screen damage

Inspect the screen in good light while the television is off. Look for cracks, impact marks, pressure damage or discoloured areas.

Physical damage becomes more likely when:

The lines began immediately after the television was moved or struck.
A crack or pressure point is visible.
The lines spread out from one specific point.
The picture changes when the cabinet is moved.

Do not press, twist or tap the panel to test it. Modern television panels are fragile, and additional pressure can make the damage worse.

Use the pattern of the lines as a clue

What you see	What to check next
Lines appear over Home and Settings menus	Run the picture test, restart the television and contact support if they remain.
Lines appear on one HDMI device only	Change the HDMI cable, input and connected device settings.
Lines appear on one free-to-air channel	Check the broadcast, antenna signal and other channels.
Lines disappear after a restart	Update the television’s software and monitor whether the problem returns.
Lines began after an impact or move	Stop pressing or moving the screen and arrange a professional assessment.
Lines appear in the built-in picture test	The television itself may need manufacturer support or repair.

When to arrange a repair

A professional assessment becomes the sensible next step when the lines:

Appear in the television’s menus and built-in picture test.
Remain after all external devices have been disconnected.
Return after a restart and software update.
Are accompanied by flashing, dark areas or loss of part of the picture.
Follow visible impact or pressure damage.
Become more frequent or spread across the screen.

Do not remove the back cover or attempt an internal repair yourself. Televisions can contain hazardous electrical components even after they have been unplugged.

Prepare information before contacting support

Collecting the following information can make the support process faster:

The television’s exact model and serial number.
The date and place of purchase.
Photos or a short video showing the lines.
Whether the lines appear in the Home menu and picture test.
A list of the inputs, applications and channels affected.
The troubleshooting steps already completed.
Your receipt or other warranty information.

The bottom line

Lines on a television screen do not automatically mean the panel has failed. First check whether the lines appear in the television’s menus, then test other sources, run the built-in picture test, restart the television and inspect its connections.

If the lines remain on every source and appear in the television’s own diagnostic image, it is time to contact the manufacturer or a qualified repairer.

Useful official resources

Information checked August 2026. Menu names, diagnostic tools and warranty procedures vary between manufacturers and television models.

TV Has Lines on the Screen: What to Check Before Booking a Repair