[LG TV Screen] The TV colors become distorted, appear reddish, or turn grayscale when the TV is connected to the set-top box.

If you notice that the entire screen appears reddish when the TV is connected to the set-top box, it may be due to a poor HDMI cable connection.

Causes and Symptoms

• The connection to your set-top box is bad.

Try this

Have you checked the HDMI cable?

➔ Try reconnecting the HDMI cable to the set-top box.

Reconnecting the HDMI cable to the set-top box

Turn off the power of the TV and the set-top box, disconnect the HDMI cable on the back of the TV, and reconnect it.

Also, remove the HDMI cable from the set-top box and reconnect it, if feasible.
Make sure that you use an HDMI cable version 2.0 or later.

Have you checked the HDMI cable using [Quick Help]?

➔ Try using [HDMI Check] in [Quick Help] in the TV Settings to diagnose the condition of the HDMI cable.

The [Quick Help] feature allows you to check if the HDMI cable is faulty or not. (Only applies to products released in 2019 and later)

Running [Quick Help] in the Settings menu

Press and hold the [9] button on the TV remote for more than 1 second and select → [Check TV Status] → [Check RF/HDMI] → [Start Diagnosis] → [Learn More]

① Check Items

② Check TV Status

③ Check RF/HDMI

④ Start Diagnosis

⑤ Learn More

About HDMI cables (faulty cables)

If there are any abnormalities discovered from the test, replace the HDMI cable with a genuine cable.
If the problem does not occur in the picture test, please contact the set-top service provider. (e.g., cable TV, Skylife, IPTV)

Does the screen appear black and white even after checking the HDMI

➔ Go to [Settings] and start [Picture Test] to check if the picture works normally.

Running [Picture Test] in the Settings menu

webOS 5.0

[2020 WebOS 5.0] Press the button on the TV remote and select [All Settings] → [Support] → [Additional Settings] → [Picture Test].

Turn on the TV and press the [Settings] button on your TV remote.
Select [All Settings] in the [Settings] menu.

① Select [Support] and then ② [Additional Settings].

Select [Additional Settings] and then ③ [Picture Test] menu.

Perform [Picture Test] to check the screen condition.

[Prior to 2019] WebOS

[2019 WebOS or before] Press the button on the TV remote and select [All Settings] → [Picture] → [Picture Test].

Turn on the TV and press the [Settings] button on your TV remote.
Select [All Settings] in the [Settings] menu.

① Select [Picture] and then ② [Picture Test].

Perform [Picture Test] to check the screen condition.

If the image on the test screen appears okay, it indicates that the issue lies with the broadcast signal and not the TV itself.
If the problem does not occur in the picture test, please contact the set-top service provider. (e.g., cable TV, Skylife, IPTV)
If the problem persists in the picture test, please contact LG Electronics Service Center.

Note

[Products released in 2020 or later] WebOS 5.0 or later

There is an [Accessibility] function in your TV that can enable black and white display during TV operation.
If the [Grayscale] option is enabled in [Accessibility] in the TV Settings, disable it.

Press the button on the TV remote and select [Accessibility] → [Grayscale] → [Off].

This guide was created for all models, so the images or content may be different from your product.