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Regardless of the age of your LG TV, horizontal lines on screen can be a major annoyance that can’t be ignored once noticed and need to be fixed.
Many people just trash their TVs and get new ones, but I’m here to tell you that you definitely don’t have to do this – you can easily fix LG TV horizontal lines with just a little know-how and effort.
This guide contains every proven fix for these horizontal lines and will help you get your TV back up and running again, whether an LG OLED TV or standard LCD TV.
LG TV Horizontal Lines on Screen
To fix LG TV horizontal lines on screen by checking all HDMI and signal cables are securely seated with no oxidation on their contacts, then try squeezing the bezel of your TV next to the horizontal line in case the gate drivers have come loose. Finally, try removing your LG’s back panel and clean the contacts on the T-Con ribbon.
See exactly how to perform these fixes below, with detailed step-by-step guides to every fix.
I’m very confident that at least one of these fixes will work for you, so let’s start with the simpler solutions before moving into possible hardware fixes.
You can watch a quick overview of each fix in the video below, with more detail following in this article.
1. Power Cycle Your TV
With modern electronics, it’s possible that the horizontal lines on your LG TV are caused by something stuck in your TV’s flash memory.
Power cycling your TV will clear out any issues with non-permanent memory and reset your main board without losing your personal settings.
This is quick and painless and won’t cause you to lose any of your saved settings.
- Switch off and unplug your TV.
- Hold down the physical power button on the TV for at least 15 seconds.
- Wait for at least 30 minutes for any residual power to drain from the TV’s capacitors (which are capable of storing charge for several minutes).
- Plug your TV back in and try switching it on. You should see a red light if you have been successful.
Make sure you do wait for the full 30 minutes before plugging your TV back in – you would be surpised how long the components within your TV can hold charge, and you want to make sure it has fully reset.
Although this seems a very basic step, don’t overlook it because in the vast majority of cases a simple soft reset fixes most issues.
Most people will now have their TV fixed and back up and running. If this isn’t you, then we’ve got a few more basic fixes to try before getting into the hardware fixes.
2. Unplug Your HDMI Cables
There’s a strong possibility that a poorly seated cable is creating signal noise which is displaying as horizontal lines, and is also a common cause of purple tints on LG TVs.
This comes down to either a:
- Faulty HDMI cable with a break in it
- Damaged HDMI port with broken pins
- Poor HDMI connection where the cable and connector are not fully making contact
To check your HDMI and other cables:
- Switch off your TV.
- Remove any HDMI or other physical cables connected to the back of your TV.
- If you have any compressed air, use that to clean the contacts both of the cable and in the connector on the TV. If you don’t have compressed air, then blow gently on them.
- Firmly push the cables back into their slots on the TV.
- Switch your TV back on again.
It that hasn’t fixed the problem, then try using a different HDMI input. Most TVs have 3 or 4 HDMI ports.
If you have one that is on a different part of the TV then that would be the best one to try, as it this should have a separate connection to the TV’s main board.
Plug you HDMI cable into the new port, note the number next to it, then choose this HDMI input on your TV, by using the Input or Source button on your TV remote or the Input or Menu button on your TV itself.
You can also try removing all external devices, including those connected by Bluetooth and any coaxial or signal cables, so that the TV only has a power cable going into it.
When you turn your TV on, this means the screen will be black as it is not receiving any picture, potentially making it tough to see any horizontal lines.
Pull up the on-screen menu to see if the horizontal lines are still there. If they are, this means that your external connections are fine and the problem is located within the hardware of your TV.
If the lines have gone, then try re-seating your HDMI and other cables one by one, until you find the damaged cable that needs replacing.
3. Confirm Your Wall Socket is Properly Supplying Power
Because flat screen TV’s rely on a constant power supply, when there are fluctuations in voltage these can show up as inconsistencies with the backlight, causing dark areas on your TV.
If your TV is on, then you know that your wall socket is suppplying power, but the question is whether this is constant without fluctuations and is of a sufficient voltage.
The most common cause of low voltage from wall sockets are faulty surge protectors.
If you don’t have a wall socket testing rig, then just unplug your TV, remove any surge protectors and try another appliance that you know draws a similar current. Check if this works as expected.
You can also plug your TV into another wall socket, preferably one located on the other side of the room from the current socket, again without any surge protectors or consumer extension cords that you might be using.
4. Try a Manual Pixel Refresh for LG OLEDs
Modern LG OLED TVs run a scheduled pixel refresh at regular intervals to prevent image retention and stuck pixels.
This works by scrolling a horizontal bar down the screen and this process can help to fix any horizontal lines you might see.
To initiate a Manual Pixel Refresh on your OLED LG, go to Settings -> Picture -> OLED Panel Setting -> Pixel Refresher.
It’s important to remember though, that running the manual pixel refresh more than once in quick succession can negatively affect the peak brightness and color reproduction of your TV, so make sure you only try the manual pixel refresh once.
5. Update Your TV’s Firmware
Software and firmware issues have been known to cause problems with the display on LG TVs.
As with any product, you should ensure that you have updated your TV’s firmware to the latest version, even if it is new.
Smart LG TVs support auto-updating of firmware, but you can’t assume that this is turned on for you.
To check that auto-updating is on for firmware / software on your smart LG TV:
- Press the Settings button on your remote and go to All Settings.
- Click Support.
- Then Software Update.
- Agree to any terms and conditions that may popup, then switch on Auto Update if off.
- You can also manually check for updates here.
For older LG TVs:
- Press the Settings button on your remote and go to All Settings.
- Go to General.
- Then About This TV.
- Check Auto Updates are on, and use the Check for Updates button to manually see if you are running the most recent firmware version.
For some LG TVs, you’ll need to update the firmware by USB. To do this:
- Go to the LG Software Drivers site.
- Enter your TV’s model number and find it on the site.
- Put a USB stick into your computer and create a folder on it called LG_DTV.
- Right-click the firmware ZIP file on LG’s site and Extract All to the folder on your USB stick.
- Once complete, eject your USB stick.
- Insert the USB stick into your TV’s USB port and switch it on.
- The TV will automatically search for the folder you created and should display USB UPDATE READY.
- Select Install.
- Follow the on-screen instructions, then switch off your TV for 10 seconds and power back on to complete the update.
6. LG TV Factory Reset
Returning your TV back to its factory settings is a more extreme step, as it will delete any personalization features, downloaded apps or connected devices, but it’s always worth a shot when other methods haven’t worked.
To factory reset an LG Smart TV:
- Press the Home button on your remote and go to All Settings.
- Then General.
- And System (or skip to the next step on older models).
- Choose Reset to inital settings.
- Follow the on-screen instructions and hit Confirm.
- Enter your PIN, which by default is 0000 (four zeroes) or 1234 for LG.
- Then select Restart in the popup.
If you don’t have your remote, then to reset an LG TV:
- Hold down the TV’s Power Button for 10 seconds, which will be underneath the screen on on the side.
- Use the Vol + or – or Channel + or – to scroll to Menu.
- Go to All Settings.
- Then General.
- And Reset.
- Follow the on-screen instructions and hit Confirm.
- Enter your PIN, which by default is 0000 (four zeroes) or 1234 for LG.
- Then select Restart in the popup.
If you have changed your LG TV’s PIN and can’t remember what it is:
- Press the Home button on your remote and go to All Settings.
- Then Support.
- Go to Advanced Settings.
- Then Safety.
- And Reset Password.
- On your remote, press Channel Up twice, then Channel Down once, followed by Channel Up once.
- Put 0313 in the box.
- Then 0000.
- Then choose a new PIN that you can remember.
That should solve most horizontal line issues without you having to delve into hardware problems, but just in case you still have a problem then it’s likely you will have to open up your TV.
7. Check the Gate Driver Contacts
Row drivers, or gate drivers, are located along the edge of your TV panel and fire each row of pixels in turn, starting from the top.
When one these gate drivers fails, you will see a thin black horizontal line on your TV for each failed driver.
Gate drivers are connected to the TV’s panel by a ribbon cable, and the contact can sometimes come loose. They are bonded within the factory so are not user-replaceable, but you might find that squeezing the sides of your TV next to the thin black line helps to resolve it.
For TVs that use double-row drivers, the black line will only span half the screen, if it has only failed on one side.
If your TV shows a complete black line across the screen, then you can assume you have single row drivers. Try squeezing the panel on both sides unless you know which side the gate driver is on.
If this does resolve the issue, then opening the back panel using the instructions in the next step, and applying tape to keep pressure on the ribbon cable should fix it.
If the issue isn’t fixed, then either the gate driver itself is faulty and needs to be replaced, which most probably requires a new panel, or there is a possibility of an issue with the T-Con board.
8. Remove Back Panel and Re-Seat the T-Con Cable
The Timing Control (T-Con) board is a small PCB board that drives your TV’s panel, translating the signal into a picture on your screen.
It’s hidden away under the back panel, behind the screen, and is a regular source of horizontal lines in TV images because it connects to the LCD / OLED panel with ribbon connectors which can come loose.
To access the T-Con board, you need to remove the back panel. If you’re not confident doing this, then now is the time to get an expert in. Otherwise:
- Unplug your TV, hold down the power button and wait for at least 30 minutes. There are large capacitors in the power board for the backlight and these can hold charge for an extended period of time.
- Place your TV face down on a large table or workbench. Make sure there is nothing that can scratch the screen on your work surface.
- Ground yourself.
- Open your TV by unscrewing the screws in the backpanel. It should come apart in two pieces: front and back.
- Put the back panel somewhere out of the way and take a look at the circuit boards that have been revealed.
- You will see a T-Con panel for translating the signal into a TV picture, a power board and a motherboard board.
Or take a look at the video below for how to remove the back panel.
The position of the boards will vary by model, but the T-Con board can be identified by the ribbon cables connecting it to the TV’s panel. Identify the main three boards you will see in the images below.
Start by giving everything a good clean, preferably with compressed air. It’s possible that dust in the connector can block the signal.
Then, you should be able to remove the cables by pushing the locking cover down and they will then easily come away from the board. Don’t try to force them out without unlocking them first.
After removing the ribbon cable, take a look at the individual connectors on the ends of the cables, and the connectors in the socket. You are looking for any signs of corrosion, damage or dust.
The contacts should be a shiny gold or silver color. If they are dull and appear to have a rough, copper-like layer over them, this would indicate oxidation and therefore a new cable is recommended.
Give the cable and socket a good clean with compressed air, then put the cable back in, put the back panel back on your TV and fire it up.
If there are still horizontal lines, there’s a good chance that there is a fault somewhere on the T-Con board itself. These can be replaced for around $30 from eBay.
To get the correct board, note the T-Con model number written on the label on the board, and put this into eBay.
T-Con connection issues are generally implicated in vertical lines in TV screens, rather than horizontal lines, but this is worth a try if none of the other steps have worked for you.
9. Use Tape to Block the T-Con Signal
This might seem like a bit of a hacky approach, but it is possible to use small pieces of non-conductive tape to block the individual contacts on the T-Con cable.
This blocks the “bad” signal getting sent through that contact, and can actually clear up the image.
This works because the T-Con cable sends a clock signal through a handful of the pins (usually 8 pins per cable) and any one of these clocks failing results in an improperly sent signal and horizontal lines on screen.
And with two cables, one for each side of the TV, you can use the signal from the working side of the T-Con board to fill in for the faulty clock signals on the other side.
It can take some trial and error to get this right, so I recommend you check out the video below for a good demonstration of how to follow this approach.
LG TV Support and Warranty
You can check your warranty information direct with LG.
Unfortunately, warranties typically only last a year unless you have already paid to extend it.
Although you are unlikely to see horizontal lines on an LG TV under one year old, this can happen. If so, return your TV under warranty and get it fixed.
You can use the LG support site to help diagnose your problem, but if you are at this stage, then you are better off calling them direct on:
- 850-999-4934 or 843-243-0000 (Mon. – Sun., 8am – 9pm EST)
You can also email them directly, or even email the president of LG customer care!
Even if LG won’t fix your TV, they might still offer you a discount off a future model if you pester them hard enough! This is always worth a try in my experience.
So, How Do You Fix Horizontal Lines on an LG TV Screen?
To fix LG TV horizontal lines on screen:
- Try to reseat the HDMI and other external cables.
- Power cycle your TV to clear the flash memory.
- Check your power supply for consistent voltage.
- Try a manual pixel refresh for LG OLED TVs.
- Update your LG TV’s firmware if using an older model.
- Factory reset your TV.
- Return under warranty or take to a TV repair shop if you don’t want to open it up.
- Check the gate driver contacts and potentially tape them to your panel.
- Re-seat the T-Con cable and potentially replace the T-Con board.
If you haven’t been able to fix your problem using the steps above, then your next port of call should be to LG customer support, who can advise you if they are able to fix it.
If not, then you can try a local TV repair technician, but if they are unable to help, then unfortunately you are most probably looking at having to get a new TV.
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