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Why does my Toshiba TV have blue lines?

As an owner of a Toshiba TV, I was recently frustrated to discover blue lines running across the screen. After doing some research and testing, I’m here to share how I solved the issue and other potential solutions I discovered. In this blog post, I’ll explain why my Toshiba TV had blue lines, and what steps I took to fix it.

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

Common causes of blue lines on Toshiba TVs
– Loose or blocked cable connections
– Visual screen or component damage
– Faulty t-con board
To fix the blue lines:
– Check the cables
– Look for damage
– Change or reset the video settings
– Tap the back of the TV
– Run a picture test
– Reset to factory defaults
Make sure to switch the TV input and the television input
The T-con board needs to be replaced if it’s damaged or faulty

Why does my Toshiba TV have blue lines?

Below are likely reasons why your Toshiba TV has been experiencing blue lines.

Loose cables

A common reason for blue lines is loose cables. Loose cables result in 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.

Loose cables are less likely to be the cause if there are blue lines when you are streaming content online.

Material or debris cable disruption

Another common reason is debris causing an interruption to the connection. Debris, dust, or other material can 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.


Another possibility is that the TV is actually faulty.

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 Toshiba 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 Toshiba TV

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

However, below are options you have when getting rid of them.

Check the cables

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

As mentioned earlier, 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 or resetting your Toshiba 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 might seem like an outdated gesture from the analog antenna days to get the picture to show but give the back of your Toshiba 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.

Picture test

Many modern Toshiba TVs have an integrated feature that allows you to see if your display is corrupted.

Different Toshiba models have different interfaces that display this information, but you can usually find this function in the settings menu along with a support or troubleshooting option.

Some models just have a picture test option that provides the results. This is a crucial step if you’re planning to contact technical support.

Reset to factory defaults

It would also help. to try testing the settings of your TV to their factory defaults.

Read more: How long do Toshiba TVs last?