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How to Fix a TV that Keeps Flashing Red/Green Lines


TV flashing red and green lines

Why Does my TV keeps flashing?

A TV can keep flashing different colors because of a loose connection, electrical interference or a failing power supply.

Flickering of your TV screen is a common problem and can disrupt the viewing experience. This can be due to multiple reasons, both internal and external, that can often be rectified with some basic troubleshooting measures.

Some common reasons why your TV keeps flickering are given below.

  • If there is a loose connection with the cable used to connect the TV, you may see flickering. Sometimes, a defective cable can also cause this problem.
  • Dust and hair accumulation in CRT sets cause electrical arcing that in turn results in the images appear as if they are jumping or squiggling.
  • Electrical interference because of multiple appliances connected to a single circuit and drawing power from the same circuit triggers flickering on the television set.
  • A failing power supply that is not able to maintain the required voltage level causes an abrupt change in the level of brightness and dimming of the TV screen.


Troubleshooting TV screen flashing problems

Some TV screen problems can be easily identified and corrected by yourself while some may require the expertise of a qualified electrician.



  • The cable connected to your set has a loose connection. Pushing it in gently and ensuring the tightness will solve the problem. Alternatively, if you have a defective cable, going in for a replacement will get rid of the flickering.
  • Dust accumulation on the TV can also be a reason for flashing. Cleaning the set can help to get rid of the squiggling. Maintain a humidity level of 70% or above and that can help get rid of arcing.



  • The TV may blink if the problem is with the power source. Remove the power plug and connect it to another source.
  • The backlight that lights up the liquid crystals on the screen is faulty and the lighting doesn’t take place as effectively as before. To fix this issue, you’ll need a backlight array replacement.


Green lines

  • The graphics card of the television is malfunctioning. Connect a second monitor to the LCD TV and check for green lines on the second screen. If they appear, you’ll have to go in for a replacement.
  • The pixels may have got stuck on the screen. Use a soft damp cloth and wipe gently over the green lines with mild pressure to release the stuck pixels.


Red lines

  • In plasma TVs, red lines appear because of image persistence due to the burn-in of phosphorus that displays images. The red lines disappear on their own within a few minutes of viewing until another burn-in happens.
  • Often, a defective HDMI cable that needs to be replaced causes red lines to appear on the screen. Also, check for faulty connections with other devices like a DVD player connected to the plasma TV.


Why Does my TV Keep Flashing Green Lines?

The most common reason for the TV to flash green lines is because of a bad matrix driver or screen matrix.

Some ways this can be fixed are as follows.

  1. If you are using the Samsung UE46F6670, unplug all the cables connected to it other than the power cable.
  2. Check if the green lines are present without any image input. If they are, the problem is with the monitor hardware of the television because of the LED display, the electronic controller or the flat cable behind the TV that connects the circuitry and the television. If not, the problem is with the connector or cable and needs a replacement.
  3. If you have the problem with your Samsung UN46C6500 TV, you can set the Auto Motion Plus feature to Clear mode to get rid of the green lines. However, the picture may become blurred and you’ll need a firmware update.
  4. If the problem occurs on an LN52A850 TV while changing the connection from a DVD player to Direct DVR, connecting the TV to the DVD player once again and then changing it to the Direct DVR solves the problem.
  5. Your TV may have a bad IC on a logic board or a defective internal ribbon interconnect that needs a replacement.
  6. There may be a problem in how the video signal gets encoded or decoded because of a bad video cable connection. Unplug the video cable at both ends and then put it back on. If you still have the problem, turn off the TV and remove the power connection for five minutes. Turn on the power supply, turn on the television set and check to see if the green lines are showing again.


TV flashing red lines

The most common reason for the TV to flash red lines is because of the reasons given above in the Troubleshooting section. The lines may also appear due to a TAB error. Some simple fixes for this are as given below.

  1. If you experience the red line problem on a Samsung UA37D5000, remove the back of the TV and apply mild pressure on the flat ribbon cable entering the LCD panel to the main video board. Do this at the entry point.
  2. Tap the top of the TV a few times at the rear where the lines are present and the lines will disappear.
  3. If your Samsung TV is connected to an Xbox X or a PS4 Pro, you may want to remove the console. Sometimes Samsung televisions are not compatible with these.


TV keeps flashing different colored lines

  1. If you have this problem with a ViewSonic N2750w or a HiSense LED television, this could be because you’ve entered the Diagnostic Color Test mode. Keep the TV on and press the Menu and Enter buttons together on the remote control. After this, press the Power button on the TV.
  2. In case you’ve got an LG TV, pressing the Exit button on the remote control might work. However, if you have a 37LC2D model and press the Menu, Enter and Power buttons simultaneously before the green power light completes flashing, the flashing color lines will go off.
  3. If you have a JVC TV, reset the EPROM by unplugging the power connection. Press the Power button on the TV for about half a minute. Plug in the power connection once again and turn on the TV.

If the above method doesn’t solve the problem, press the up and down cursor arrow buttons on the remote control followed by unplugging the power connection and plugging it again.

In case the problem persists, try repeating this with the left and right arrows. If this also doesn’t help, there is an EPROM failure and it will have to be replaced. You can also try pressing the Exit button on the remote control.


TV keeps Flickering On and Off Lines

You can try the following steps to resolve the flickering lines problem.

  1. Turn the television off and turn it on again. This will reset the TV.
  2. Disconnect the plug from the power outlet for five minutes.
  3. Check the cables going to the TV and coming out of it for proper connection.
  4. Disable the Energy Efficient feature through the TV menu.
  5. Check for connection of one or more faulty components.
  6. Change the input source to determine if the problem is with a component or the TV.


Troubleshooting a TV Flickering On and Off Lines

  1. The backlight array may have a problem and might need a replacement. Getting a replacement done might solve the problem. Replace all the LED strips at the same time as they deteriorate at the same rate. To check if this is the problem, flash a torchlight on the screen and keep the volume button pressed. In case there is a fault, the screen will display an image.
  2. The computer graphics card or cable may be at fault if you have an LG47LB5900-UV TV. The faulty part will have to be replaced to fix this problem.
  3. In a TCL TV, the flickering lines could be because of leaking or bulged capacitors or a problem with interconnected wiring. Getting the capacitors replaced or the wiring set right might resolve the problem.
  4. Changing the TV brightness and picture mode to normal can sort out the issue of flickering in a TCL TV.
  5. For a TCL 49D100BAA television with HDMI arc input, turn off the unit followed by unplugging of the power cord and HDMI cable. Press the power button and wait for at least five minutes. Plug the power cord again, turn on the TV and do a factory reset. Also, ensure that all cables are connected properly.


TV Keeps Blinking On and Off Lines

  1. If you have this problem with an LG47LB5900 TV, you may need to get the LED backlight strips replaced. The back panel will have to be removed to do this.

To ascertain that this is the problem, keep the TV in a dark room and turn the set on through the Set Up menu. Flash a bright torchlight on the screen and check if the Setup screen is visible on the unit.

  1. If your Samsung LA32R7B LCD TV power indicator keeps blinking without turning on, the capacitors in the power supply unit may have to be replaced because of bulging or drying. This can be ascertained by opening the back panel and checking for the same. Sometimes, the mainboard itself may have to be replaced with a new one.

You can also try connecting the television to another power outlet to determine if it’s a power source related problem.


How to fix a TV screen that keeps blinking lines

The following steps can help you to fix a Samsung TV screen that keeps blinking lines.

  1. Deactivate the Eco Sensor feature that is available below the Settings main menu option. This turns off the brightness adjustment for the automatic ambient light that can, in turn, be a cause for flickering.
  2. Doing this can stop the television from adjusting the brightness automatically depending on the program you’re watching.
  3. Connect the TV to another power source, if the above two steps don’t help you to arrive at a solution. The blinking could be due to a simple problem like a malfunctioning connected device, a bad connection or a faulty cable.


Samsung LED TV flashing red light lines

  1. The TV has one or more bad capacitors on the main logic board or a bad panel that may need a replacement.
  2. Try changing the batteries of the remote control. Sometimes, these weak or failing batteries can trigger this problem.
  3. Disconnect the power source that gets plugged to the TV at the back and leave it overnight. Connect it again the next day.
  4. The board opposite where the power cable is plugged in may have to be replaced.
  5. Getting the burned out or shorted LEDs in the backlight array replaced is likely to stop the red light from flashing. You may have to replace the array completely if you don’t get the LEDs separately.
  6. The power board, main motherboard or inverter may need to be replaced. Replacing the latter may be an expensive deal. Sometimes, it may be just a faulty component in any of these parts.
  7. Disconnect all devices connected to the television and turn it off and then on again.
  8. Turn off the television at the wall socket and turn it on the same way instead of using the remote control.


Samsung TV LED flashing 5 times lines

  1. In a Samsung UN60H6350AF, the mainboard is likely to be at fault and may need a replacement.
  2. You may need to get the backlight array replaced as the LEDs may have got shorted or burned out.


Samsung TV Flashing when turned off lines

  1. Remove the batteries from the remote controls of all the external devices connected to the television. Keep the TV unplugged for five minutes and then turn it on again. You can also check by removing the batteries from one device at a time.
  2. Turn off the “Auto shutdown” and “Anynet” settings. You will often find them in the Systems or Smart Hub menu.
  3. In a Samsung 55ES7100 TV, turning the Light Effect option to Always On often helps to solve the problem.


LG TV Keeps Flashing Lines

  1. To fix this problem in an LG 55IN5710 television, you may need to get the faulty graphics chip on the logic board or backlight system replaced. Sometimes, only one or a few LEDs of the backlight system may be malfunctioning.
  2. The power supply board could be at fault or have faulty relays or capacitors, which when replaced solves the problem.
  3. The motherboard has a hairline crack and has to be replaced for a permanent fix. For a temporary solution, push the power cord behind the TV in as much as possible.
  4. Ensure that the air vents are open and have good air circulation to prevent the set from getting overheated and this may resolve the issue. You may also consider unplugging the TV and cleaning the accumulated dust at the plug-point. Also, check for loose connections.
  5. Unplug the LG42LN570V for at least six hours to reset the power module so that there is no static buildup and connect the set to a wall outlet instead of an extension lead.


Vizio TV Keeps Flashing Lines

  1. In a VW42LHDTV10A model, you can try replacing the worn-out capacitors on the circuit boards after removing the stand and back panel of the TV. Remember to put them back after the replacement.
  2. Check all the cable connections to your TV including the coaxial cable that comes from the cable outlet. Tighten the loose cables and replace damaged ones.
  3. Check for the Advanced Video Settings and disable all the options under it. Power off the TV and check for flickering.
  4. Unplug the TV from the power supply to discharge it and keep the power button pressed for half a minute. Connect the set once again and turn it on. You can also unplug the devices connected to the discharged TV and connect them after the discharge.


Sony TV keeps flashing lines

  1. Turn the TV off for a minute and turn it back on using the remote control or power button. If this doesn’t work, unplug the set and connect it again after a minute.
  2. Clean all the slots and vents so that there is sufficient air circulation.
  3. Turn off the TV and remove all the connected devices. Turn on the set again and check for the blinking. If there is no blinking, the problem is with a connected device.
  4. The power supply board, inverter board or main logic board may need a replacement. In some cases, there may be a backlight issue. If so, the backlight array must be replaced.
  5. To solve the red light blinking five times issue, unplug the Sony Bravia TV for 48 hours. Plug it again and at the same time keep the volume and power buttons on the TV pressed for five seconds.


Hisense TV keeps flashing lines

  1. For a Hisense 50K360G, unplug the power connection from the outlet for an hour. Keep the power button on the set pressed for a minute. Plug in the power connection once again while you continue to keep the power button pressed. Ensure that you reconnect directly to the wall outlet.
  2. In a Hisense 5020DUS, a fix to the problem may be the replacement of bad LEDs in the backlight array or a bad power board.


Insignia TV blinking on and off lines

  1. In an Insignia INC3218 flat panel TV, this may be because the boards get warmed up. Resetting the hardware by keeping the television unplugged for an entire day may be a solution.
  2. The problem could be due to loose or faulty cables. Make sure that there is a good connection with the coaxial and all HDMI cables.


Panasonic TV flashing red light lines

  1. For an LCD TV, remove the power connection from the wall outlet. Press the power button of the set for half a second and release it. Connect the power cord to the outlet once again and turn on the TV.
  2. The capacitors or other components in the power supply board may need a replacement because of overheat. Sometimes, the power board could itself be at fault.
  3. If the red light flashes 6 times, the main buffer board may have to be replaced or repaired.


TV keeps flickering when playing Xbox lines

  1. Try unchecking the Allow YCC 4:2:2 option under the Display & Sound/Advanced video settings and set the color depth to 10 bit. If you’re using a Vizio UHD TV, uncheck the 24Hz and 50Hz options. You may also want to set the resolution to 1080p.
  2. Use only the HDMI 1.4 gold plated cable provided instead of a third-party cable. Alternatively, if you’re using an HDMI splitter, connect it directly to the TV.
  3. Try using a different HDMI as well as connecting the console to another TV if possible.
  4. If you’re using an Xbox One, keep the power button pressed for about 10 seconds till it’s powered off. Unplug the HDMI cable and the power cord. Plug-in the HDMI cable and power cord once again after five minutes. Turn on the console and check if the problem recurs.


TV keeps flickering when connected to PS4 lines

  1. Turn off the Deep Color Output option. This can be found under ‘Video Output Settings’ that is under the ‘Sound and Screen’ submenu of the Settings menu.
  2. Turn off the PS4 and keep the Power button pressed for 10 seconds to start the console in safe mode. Choose the Change Resolution option and select the Automatic option for video output resolution.
  3. Unplug the TV as well as the HDMI cable at both ends. This may cause the connection to reset and solve the problem.
  4. The HDMI port on the TV or console could be damaged. Try using another HDMI port. You can also check if the HDMI cable is loose and if so, tighten it. If it’s damaged, change the cable.


TV keeps flickering when connected to PC lines

  1. Use HDMI cables with high-quality shielding and materials to avoid damage and bending or stiffening over time.
  2. Check that the refresh rate setting matches the HDMI supported by the TV. If not, do the required settings.
  3. There may be a faulty graphics driver that when replaced will stop flickering on the TV.
  4. Replace the cable connecting the PC and the TV with a cable of shorter length than the present cable or try if a wireless connection is possible. Also, ensure that the HDMI UHD color setting is off.

Read more: How to Fix horizontal lines on a TV

Ernie Lo

Ernie Lo is a qualified web designer and web developer. He works as an IT support technician and website manager at Benleigh Vending, and he also fixes vending machines.

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