Samsung TV Horizontal Lines on Screen: 6 Quick Fixes

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Samsung Smart TVs are incredibly feature-rich, and their picture quality is hard to beat. But just like any electronic, they do have their bugs.

In this article, you’ll learn how to diagnose and fix Samsung TV horizontal lines, including how to determine whether they are caused by software, firmware, or hardware problems.

What Causes Horizontal Lines on a Samsung TV?

There are only a handful of reasons for horizontal lines on Samsung TV screens. Most of them are easily fixable, especially if they are software or firmware problems.

  • Loose input cables — The cable between your Samsung One Connect box and TV (and between the One Connect box and input devices) needs to be securely connected for the picture to display properly. Loose HDMI cables are the most common cause of lines on your Smart TV and also one of the easiest to fix.
  • Old firmware — As with any electronic, your smart TV sometimes needs to be updated to the latest firmware version. Outdated graphics drivers will often cause display problems, including horizontal lines.
  • Image resolution mismatch — Your TV’s resolution needs to match the resolution of your input device. Your TV should display a message explaining this if there is a mismatch. However, image quality issues or horizontal lines could indicate a resolution problem that your Samsung TV didn’t automatically detect.
  • Physical damage to the display Any damage to your display panel or screen can cause horizontal lines. This can include water damage as well as damage from a fall or impact. It doesn’t take much to cause a failure, especially if the damage has impacted the gate driver chip that controls power to your screen.

The fixes below will help with all of these problems except display damage. While a technician may be able to help with a broken display, those repairs will often cost about as much as a new TV.

But we’re getting ahead of ourselves. Let’s try out a few of the simplest fixes before we talk about worst-case scenarios.

1. Power Cycle Your TV

We’ll start with the easiest fix. Your Smart TV is really just a computer, so restarting it will solve several common software issues.

  1. Unplug your TV’s power cord.
  2. Wait at least one minute.
  3. Plug your TV back in.
  4. Turn the TV on.

It’s important that you unplug the TV rather than just turning it off with the remote or power button. While plugged in, your TV won’t fully power cycle, no matter how long you leave it turned off.

2. Reconnect Your Input Cables

A loose input cable will often cause moving or flickering horizontal lines on the screen. This fix likely won’t do anything for permanent horizontal lines as those often indicate physical damage to the unit. It’s still worth a try, though, when the alternative could be buying a whole new TV.

If your TV is directly connected to your input devices (satellite/cable box, Blu-Ray player, etc.), you just need to check those cable connections.

For TVs that have a One Connect Box, the issue could be with either:

  • The HDMI cable from the input device to your One Connect box
  • The One Connect cable from your Samsung One Connect box to your TV

We’re going to be extra-thorough with this process because loose cables are the most common reason for Samsung TVs to show horizontal lines.

  1. Disconnect all of the input cables between your TV, One Connect Hub, and input devices.
  2. Reconnect each of the cables, ensuring that the plug is completely and securely attached to the port.
  3. If you have multiple input devices, switch your TV between them.
    1. If the lines only show on 1 or a few inputs, try tightening those cables again or replace them with new HDMI cables.
    2. If the lines show on all inputs and are moving or flickering, try tightening the One Connect cable or replacing it with a new one. Not all Samsung TVs use the same One Connect cable, so check the new one against your TV’s model number to make sure they are compatible.
    3. If the lines show on all inputs and are permanent, the cables probably aren’t the problem.

3. Perform a Picture Test

All Samsung smart TVs have a self-diagnostic feature called Picture Test. It serves as the easiest way to diagnose display compatibility issues and troubleshoot almost any display problem you might encounter.

The process for running a Picture Test will depend on the model year of your TV. If you’re uncertain what year your TV is from, just look at the available menu options and find the instructions below that match your TV’s menus.

Samsung TVs made after 2020

  1. Press the Home button on your Samsung TV’s remote control to open the smart hub.
  2. Click Settings in the smart hub menu.
  3. Select the Support tab.
  4. Click Device Care to start a quick scan.
  5. Wait for the scan to finish, then select Self Diagnosis from the bottom menu.
  6. Click Picture Test and press OK to confirm.

Older Samsung TV models

  1. Press the Home button on your Samsung TV’s remote control to open the smart hub.
  2. Click Settings in the smart hub menu.
  3. Select the Support tab.
  4. Click Self Diagnosis.
  5. Select Start Picture Test from the menu and press OK to confirm.

4. Check for Firmware Updates

Samsung frequently includes graphics driver updates and other important fixes to picture and display problems in their firmware updates. Firmware updates also have security patches and general bug fixes, so you should keep your device updated even if you’re not seeing horizontal lines.

Running a firmware update is easy, but you will need an active internet connection. The download may take several minutes, so don’t start the process until you have some time to spare.

  1. Press the Home button on your Samsung TV’s remote control to open the smart hub.
  2. Click Settings in the smart hub menu.
  3. Select the Software Update tab.
  4. Click Update Now.
  5. Wait for the download to finish.
  6. Install the update following the on-screen instructions

5. Reset Your Smart TV Picture Settings

Sometimes, it’s easiest to start from square one. You could try to figure out which picture setting is causing problems with your TV, but you’re probably better off resetting the picture settings to their defaults.

Unlike a full factory reset, this won’t impact your apps and non-picture personal settings.

  1. Press the Home button on your Samsung TV’s remote control to open the smart hub.
  2. Click Settings in the smart hub menu.
  3. Select the Picture tab.
  4. Select Expert Settings.
  5. Click Reset Picture from the menu and press Yes to confirm.

6. Factory Reset Your Samsung TV

A full factory reset is the most extreme step that you can take for software and firmware issues with your device. It will erase all of your personal settings (except network settings), returning your TV to the state it was in when you first opened the box.

I’d suggest trying all of the above solutions before proceeding. However, a factory reset may be your only option if your TV’s firmware has been corrupted. Make a note of any settings or apps you want to recover first, then proceed with these steps.

  1. Press the Home button on your Samsung TV’s remote control to open the smart hub.
  2. Click Settings in the smart hub menu.
  3. Select General.
  4. Click Reset.
  5. Enter your PIN. By default, this will be 0000.
  6. Select Reset and confirm by clicking OK.

Your TV will restart during the reset process. When it boots back up, you’ll need to set up your TV again, hopefully with the horizontal lines gone.

What’s Next?

Since we’ve already inspected the cables, this reset should have fixed all other possible bugs. The only remaining option is physical display damage. You can try contacting Samsung Support about fixing it, but you’re probably looking at a replacement.

For ideas about picking your replacement TV, check out some of the suggestions in my guide to Android TVs vs Smart TVs. Or for a cheaper alternative, you could check out ONN TVs. You could also use a Firestick on a non-smart TV if you need a temporary solution while you choose your new smart TV.

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