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How to Fix LG TV When Half the Screen Goes Black

Last Updated Mar 29, 2022
smart tv black screen mounted on a wall

If half of your LG TV’s screen suddenly goes black, there are several potential problems that can go from “somewhat bad” to “the whole TV has to be replaced.” No matter what kind of LG TV it is—LCD, LED, OLED, or QLED—the troubleshooting process is similar.

Below, we’ll cover the various troubleshooting steps you should take in the event you can only make out half of what’s going on on your LG TV’s screen.

LG TV Self-Diagnosis/HDMI Cable

If you happen to own an LG TV set post-2018, you may be in luck. LG began upgrading their 2018-2021 TVs with a self-diagnosis feature to help locate, define, and troubleshoot problems. It may not be the solution you’re looking for, but it’s worth a shot.

  1. Long press the #9 button on the remote or click Settings > All Settings > Support > Quick Help.
  2. Select Optimization Settings and run through the process just to determine that your video settings are optimized.
  3. Go back one screen and select Check Items.
  4. Select Check the Status of TV.
  5. Select RF/HDMI.
  6. Select Start Diagnosis.

If there’s a problem with your HDMI cable, it will show up here, and you’ll need to replace it. It’s always recommended to use quality HDMI cables:

Sure, some of them are priced pretty high. However, HDMI cables are largely a case of getting exactly what you pay for.

Move on to the T-Con Board (If Applicable)

T-con boards are found in other TVs, but they’re predominant in LCD models. If you don’t own an LG LCD model, check your TV’s model number and Google it to find out if there is a T-con board. Unless you’re adept at small circuit board repairs, this step may not be for you.

You’ll want to use a Phillips Head screwdriver with a static-grounding wrist strap. Be sure to wear thin rubber gloves as well. In this scenario, we’re accessing the LVDS cable to the T-con board only.

  1. Remove the back panel of your LG TV.
  2. As you remove the back cover, disconnect the appropriate cables, including the LVDS cable, which connects directly to the T-con board.
  3. The cable has a long, horizontal connector with many thin cables (usually red) attached.
  4. Disconnect the cable and check it over thoroughly.
  5. Use a magnifying glass to see the individual pins and ensure they aren’t warped or otherwise damaged.
  6. Check the casing/plastic connector and also check the thin wires all the way back to the removed panel.
  7. You’re also looking for dust or any foreign debris while ensuring that the connection wasn’t loose or partially disconnected.

The T-con board is responsible for translating the video signal into bars of the visual overlay on the LCD screen. It’s often the culprit when half of the screen goes black.

Check for Replacement Parts and DIY or Warranty

When it comes to LED displays (both the OLED and QLED varieties as well), the T-con board is rarely a part of the TV. With those types of LG TVs, you’re dealing with boards that are far more difficult to clean or replace without doing irreparable damage to the TV.

In other words, a DIY project should only be attempted if you know what you’re doing and have narrowed down the problem to a particular part.

The warranty coverage on your LG TV usually covers one year for labor and parts. If your LG TV experiences a black, half-screen display defect—inside the one-year warranty coverage—contact LG at 1-800-243-0000 or go to to contact customer support.

In Summary

Half of your LG screen going black is not usually going to mean good things will follow. To fix an LG TV when half the screen goes black, you start with a process of elimination. Begin with the cables and the LG TV’s self-diagnosis (if available), then the T-Con board cables, the board itself, the mainboard, and the panel last.

If it’s the panel or the mainboard, cross your fingers that it’s still under warranty because the repair is as costly or more costly than the LG TV itself. If you’re not comfortable or familiar with circuit boards, the T-Con solutions may not be right for you either. If it’s just your cables—or a matter of resetting your LG set—then you’re good to go, and this will be an easy fix.

Outside of that, you’re looking at replacing parts and at your own expense if your LG TV is outside of warranty coverage. In the case of older LG TV sets, it’s probably cost-prohibitive to try and play the part-swap game. If it comes to that, you’re better off upgrading your TV.

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