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9 Causes Of Horizontal Lines On A TV Screen (Updated 2023)

What Causes Horizontal Lines On TV Screen

You’re probably thinking…

“This is the end of my TV.” 

But you’d be surprised to know cases like these don’t always mean you need a new TV. 

So let’s see what’s causing this.

Read on to find out: 

  • What you can do to fix your TV screen’s horizontal lines. 
  • 9 significant causes of horizontal lines on your TV screen. 
  • How to tell whether your TV needs to be repaired or replaced. 
  • And many more…

What causes horizontal lines on a TV screen?

The most common causes of horizontal lines on a TV screen are LCD panel damage or a loose cable. Another cause could be dirt buildup at the back of your TV. Other times, it’s a software or corrupted file issue. Poor antenna reception is also possible. Lastly, it may be due to a failed T-con board. 

9 causes of horizontal lines on a TV screen

#1: Dirt and debris buildup

When was the last time you had your TV cleaned? 

Because here’s what could be happening inside your TV: 

If dirt and debris reach your TV’s hardware or components, it could damage the display. 

But don’t get me wrong. 

It’s not just the dirt or debris that causes the damage. 

When these build up inside your TV, they result in overheating issues. 

And it works the same way on other electronic devices. 

Why else do you think laptops, A/Cs, electric fans, and smartphones need regular cleaning?

It’s because improper maintenance leads to poorer device performance. 

And 1 major cause of that is overheating brought out by accumulated dirt or debris. 

Now, the biggest problem here’s that most LCD panels have backlight strips.

These are components glued to the TV screen and provide backlight for your display. 

Their number 1 enemy? 

Heat. And overheating might just cause those strips to fall off. 

In effect, you get horizontal lines on your TV screen. 

#2: Loose cable 

Sometimes, the cause of your TV’s horizontal lines is a bad connection due to your cable. 

In general, some cables can last for months. While others for as long as a decade. 

For example, if the cable was poorly manufactured, don’t expect it to function for the entire year.

I’ve bought replacement HDMI cables for my Seagate hard drive in the past. 

And guess what? 

It lasted for roughly 10 months. 

But see – here’s the thing: 

Cables don’t degrade instantly. 

Most of the time, it’s gradual. 

And 1 common sign is the cable can’t lock into the port as tightly as it used to. 

The result? 

A loose connection causes video quality issues. 

One of which is the horizontal line you see on your TV screen. 

#3: Antenna or cable box issues

Cable Box Issues

Put it this way: 

If your antenna reception’s weak, it also affects your TV’s display. 

Other times, the connection between your TV and cable box could also cause issues.

In times like these, your external device may be the root cause. 

That could mean it’s a compatibility problem or a defect in your cable box’s hardware.

Check out: Will a Smart TV Work With an Antenna? 5 Device Facts

#4: Incompatible picture settings

If your video or image size doesn’t match your TV’s resolution, you get an incompatible picture. 

And as a result, horizontal lines might appear on your screen. 

How exactly? 

When the image’s too big or small, the mismatch in your TV’s resolution causes lines to appear.  

This is rare, but nevertheless possible. 

#5: Power supply issue

Power outages are enough to cause damage to your TV’s components. 

Not to mention, they might even disrupt your electrical outlet. 

With faulty wiring, there isn’t enough power supplied to your TV. 

Let’s use an example. 

Say your TV needs at least 220 volts to function smoothly. 

If your outlet’s only supplying 150 to 180 volts, several things can happen such as:

  • Your TV doesn’t turn on. 
  • You see errors on your screen. 
  • The TV still runs but it’s struggling to display an image or video. 

So, what’s the real issue here? 

For starters… if your TV struggles to display any video, you might get horizontal lines on your screen. 

In some instances, you even might end up seeing vertical lines. 

But a more common problem that can happen due to a power outage is a fried TV component. 

Some of these include:

  • Printed circuit board.
  • LED backlight components. 
  • Your TV’s main control board. 

And as you’ll find out in the later sections, damaged hardware’s also a likely cause.

#6: Corrupted software

When I say “corrupted,” this can refer to several things in your TV’s system, like:

  • Apps. 
  • Files/media.
  • Operating system (a.k.a OS). 

Should any of these carry a corrupted file, it can cause several problems to your TV. 

Overall, corrupted files are like viruses on steroids that literally punch your TV’s guts. 

#7: Loose connection between the LCD screen and printed circuit board

Sounds too complicated? 

Allow me to explain it in much simpler terms. 

A printed circuit board or PCB basically connects all your electrical components together. 

You’ll find PCBs in nearly every electronic device such as computers and smartphones. 

Think of your TV’s printed circuit board as the heart of your device. 

If it’s damaged or worn down, any electrical component connected to it fails to work too. 

And if there’s no connection between your PCB and LCD screen, you get a broken display. 

In other words, this inevitably leads to horizontal lines on your TV. 

Over time, you may not even see any signal on your screen anymore. 

#8: LCD screen has physical damage

Did you know positioning your TV near a heat source causes physical damage to your screen? 

But how exactly? 

Through the heat, my friend. 

After all, TVs are fragile. 

Even overheating is enough to make your TV shut down on its own. 

Now, if the heat made its way to your TV’s internal components, well… guess what. 

You might just be looking at a device meltdown. 

And that’s not all. 

Powerful electrical shocks are also enough to fry your TV’s components. 

In effect, it can also cause physical damage to your screen. 

And here’s why that matters: 

Because more often than not, horizontal lines typically mean a damaged LCD screen. 

#9: Failed T-con board

Worst-case scenario, your TV’s T-con board is broken. 

What it does is it drives your LCD display. 

Your TV requires a functioning T-con board to show images and videos on your screen smoothly. 

Without it, several issues can crop up, such as: 

  • Double images.
  • A white or no display. 
  • Horizontal or vertical lines. 
  • Black and white vertical bars on your screen. 

With that, what’s the next best thing you can do? 

Keep reading as you’ll find out a list of solutions below. 

How to fix horizontal lines on a TV screen?

With all the possible causes for your TV screen’s horizontal lines, you might be thinking…

“Where do I even start?”

And I hear you. 

So, let’s take this one step at a time, starting with…

#1: Test different cables and external devices

If the horizontal lines on your TV screen are because of loose or damaged cables, do this first: 

Grab a new HDMI or coaxial cable and plug it into your TV’s port. 

At the same time, try using another external device. 

If you have a spare Fire Stick, Roku, or hard drive, test this on your TV ports as well. 

Now, why do this? 

Because if the root cause’s a damaged cable, this should easily clear the horizontal lines. 

#2: Switch between different TV inputs

All smart TVs nowadays have several ports at their back or side panels. 

And as a result, each port also corresponds to a specific TV input. 

For example. 

You might have the following TV inputs: 

  • AV. 
  • PC. 
  • Video 1. 
  • HDMI 1/2/3. 

Now, say the problem is with your TV’s AV input. 

Then, it could mean that all your other inputs (HDMI, PC, and Video 1) are working fine. 

And overall, it could either be a problem with your AV port…

  • Cable.
  • Hardware. 
  • Connection. 

But if you see the same horizontal lines on all of your TV’s inputs, let’s try…

#3: Doing a picture test

“What’s the point of this test?”

Put simply, the TV runs a series of tests to diagnose and troubleshoot software issues. 

In most cases, it should help clear your current issue. 

Provided, of course, that the problem lies with your TV’s software. 

Accessing your “Picture Test” settings varies per TV. 

For example. 

On LG TVs, you’d have to…

  1. Tap the settings button on your remote. 
  2. Select “All Settings” from the drop-down menu.
  3. Click on “Picture.”
  4. Tap “Picture Test.”

For most TVs, you’ll find “Picture Test” in your “Support” menu followed by “Device Care.”

On a Sony TV, you can locate it on the “Status & Diagnostics” menu. 

Finally, check out this video of how to perform a picture test on a Samsung TV: 

#4: Reset your TV to its default settings

If a picture test didn’t remove the horizontal lines on your screen, it’s time for a hard reset. 

No – that doesn’t mean whacking your TV. 

It’s a setting all TVs have that’s meant to…

  • Clear any software problems on your TV. 
  • Resolve corrupted files, errors, or glitches in the system. 
  • Wipe all your TV’s data and restore it to its default settings. 

But there’s also 1 crucial reason why this solution’s necessary: 

And it’s to find out whether the horizontal lines on your screen are caused by your TV…

  • Software or system. 
  • Hardware or faulty components. 

Now, you can find the hard reset setting on your TV’s “General” menu. 

From there, simply click “Reset to Initial Settings.”

Note: Sometimes, the setting will be labeled as “Reset.”

Similar read: 9 Reasons Your TV Screen Is Black + How To Fix It

#5: Contact a professional or technician

When a hard reset fails, the solution and problem are clear: 

Your TV has a damaged hardware component and needs a professional diagnosis. 

This means calling the service technician of your TV’s brand and requesting a repair. 

From here, a proper diagnosis should present you with 2 options: 

  • Repair the faulty component. 
  • Replace the damaged hardware. 

Of course, it’s best to let a professional handle any repairs or replacements.

But if both options are too costly, your last resort is to buy a new TV.