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Why does my Samsung TV have blue lines?

As an owner of a Samsung TV, I was incredibly frustrated to find that my beloved television had suddenly developed blue lines running across the screen. I wanted to find out what was causing this issue and how I could fix it, so I did some research and testing.

Through my journey, I found solutions that worked for me and I wanted to share my experience and other solutions I discovered in case anyone else is running into the same problem.

The most common causes of the blue lines issue are loose or blocked cable connections, visual screen or component damage, or a faulty t-con board. 

Quick Tips
Loose cables or cable disruption could cause blue lines on TV.
Check the cables to ensure they are properly connected.
If cables are fine, try changing the TV’s video settings.
Tap the back of the TV or do a software update to fix the issue.
Soft reset or hard reset the TV as a last resort.
If the issue persists, consider replacing the T-con board.

Why does my Samsung TV have blue lines?

There could be many causes of blue lines on your television, with the most common being:

Loose cables

Loose cables indicate there’s a poor connection to the television from another device. If you’ve shifted around your TV, this could be the reason you’re experiencing blue lines.

Material or debris cable disruption

Debris, dust, or other material could interrupt the connection, so it’s also important to clean out the connector piece before reconnecting the cable and television. Don’t forget to check the other end of the cable as well.


Damage to the screen or unit due to impact from an object or the floor is one of the leading causes of anomalies.

The backlighting component inside your set provides the screen with light, so if it gets damaged or blocked, the light will only shine through on certain lines.

Another part that could be damaged is the screen. If it absorbs some sort of impact, it can cause a variety of line colors to appear, including blue.

Faulty t-con board

A Samsung T-con board generates the vertical and horizontal timing panel signals while enabling signals and providing panel boas.

This component looks like a computer motherboard and controls the logic gate signal and serves as the source for propelling the thin-film transistor (TFT) LCD.

Since this component directly controls the vertical and horizontal signals, it could cause blue lines to appear.

How to fix the blue lines on a Samsung TV

The blue lines could be a simple or complicated fix, depending on if there’s damage to any part of the television.

Check the cables

The first step you must take is to check both ends of all video cables.

As mentioned, the connections could be loose, especially if you recently shifted around the television, or could have material blocking the connection between the cable and the TV input or set-top box output and cable.


Next, conduct a visual search for any damage that could be present. If the TV has recently fallen on the ground or sustained some form of impact, then you want to

Television settings

If the root cause isn’t damage or loose cables, try changing your TV’s video settings.

Start by switching the TV input to a different HDMI port since the one you’re using could be defective or damaged.

This can also help rule out different ports. Remember to switch the input on the television as well so you don’t receive a “no signal” error.

T-con board

While this may seem like an outdated gesture from the analog antenna days to get the picture to show but give the back of your TV a tap.

This sometimes causes the internal componentry to reconnect if loose. If it briefly works but lines reappear, then you may have problems with your T-Con board.

Once the T-con board is damaged, faulty, or has an issue, it will need to be replaced to ensure a properly functioning television.

Try a software update

There is a possibility that there is a software bug causing the issue. You can turn on automatic software updates by going ”settings” then ”support” then “software update” and ensure ”Auto Update” is turned on. Alternatively, you can manually update over the internet by clicking ”Update now”.

Try doing a soft reset

Often, a soft reset is all that is needed to solve issues on a Samsung TV. A soft reset does not erase any data. To soft reset a Samsung TV, you simply need to turn the TV off, then remove the plug from the wall outlet and wait for 60 seconds, then put the plug back in and turn the TV on again.

Try a hard reset

A hard reset involves completely reseting the TV to its factory defaults and your data will be erased.

To do this, do the following:

  1. Turn on the TV and press the “Home” button on the remote
  2. Go to “settings”
  3. Then click “general”
  4. Then click “reset”
  5. You must then enter a 4 digit pin number which is 0 0 0 0 by default
  6. Then click ”Yes” to reset the TV
  7. The TV will then turn off once it has finished resetting
  8. You can now turn the TV back on and set it up again

Do a Picture Test

A picture test is a self-diagnostic process that allows the TV to identify the problem and find a suitable solution. 

To do this, do the following:

  1. Press the “settings button”
  2. Go to “Support”
  3. Go to “Device Care”
  4. Go to “Self diagnosis”
  5. Then click “Picture Test”

Ensure that the cables are connected correctly

It could be the case that the blue lines are being caused by a problem with the cables connected to the TV especially the HDMI cables. It would help to make sure that they are connected properly. If you happen to have another HDMI try using that as instead and see if it solves the issue.

Read more: Hard reset Samsung TV without a remote