LCD & LED TV Repair – No Image & Blank Black Screen Flashlight Test – How to Fix LCD & LED TVs

LCD & LED TV Repair – No Image & Blank Black Screen Flashlight Test – How to Fix LCD & LED TVs

LED & LCD TV How to Diagnose Symptom of No Image on the Screen

Tutorial for Samsung TV No Image on Screen
Tutorial for Vizio TV No Image on Screen
Tutorial for Sony TV No Image on Screen

This flashlight test will show how to identify if you have any video appearing on the screen and whether or not you have backlights. Within this test, we will show how to determine if the problem is a bad t-con board, bad main board or bad backlight inverters for LCD TVs or LED driver for LED TVs.
Most LCD TVs are made up of a main board, a t-con board, power supply board and backlight inverters. Some TVs have one backlight inverter, some TVs have two backlight inverters and some have the backlight inverter built into the power supply board.
Most LED TVs will have a t-con board, a power supply board, a main board and an LED Driver board. Some LED TVs will have the LED driver board built into the power supply board.
If you have no picture on your screen, the first thing we will want to look at is to see if we have backlights or not. You can do this in a few different ways. The first is by looking through the back of your TV and seeing if you can see white lights shinning through holes on the panel.
You can do this a few different ways. The first is by looking through the vent holes on the back cover of your TV and seeing if you can see white lights shinning through the holes on the panel. Be sure to turn off all the lights in the room. As you can see on the screen, we can see the backlight is on through the top vent on the TV.
If it is too difficult to notice if your backlights are on or not, with the back cover still on, you will need to remove the back cover of your TV and look for the light shining through the panel.
Here is what the chassis looks like with the back cover removed and the backlights working. Once you have determined if you have backlights or not, you can then move on to the next steps.
If your backlights are working, but you have no image on the screen, that means the problem is either the t-con board or the main board. Next, you will want to see if you can hear audio. If you cannot hear audio, try and remember if you had audio immediately after the TV image went away on the screen the original time. Or you can also cycle through the inputs to see if you can hear any audio on any of the inputs. For example you could connect your cable box to your TV and try to find the input for that cable box knowing that it would be sending audio to the TV.
If you do have audio and you do have backlights, I recommend starting by replacing the t-con board as that will be the fix, the majority of the time. If you definitely have no audio and you do have backlights, then the problem could either be the t-con board or the main board. You will need to replace each board individually to see which one fixes the problem.
If you do not have backlights, you will want to turn all of the lights off in the room and get a flashlight. Apply power to your TV and press the menu button on your remote to pull up the menu on the screen. You will not be able to see the menu until you shine a flashlight on the screen.
You may need to twist the flashlight and try different angles to be able to see the menu. As you can see on our screen, the menu shows up and you can even read the AV1 on the screen.
This shows that the TV has no backlights, but the image is showing up on the screen, thus our inverter and LED driver is bad and our T-con and main board are good.
You can see on our screen that I can turn the menu on and off and the image appears and then disappears. At this point you will want to replace the inverter or LED driver or the power supply if it has the inverter or LED driver on it.
So as a brief overview, if your TV does have backlights and has audio, I recommend replacing the t-con board first. If your TV does have backlights but does not have audio, then it is either a bad t-con board or main board, and each board will need to be replaced individually to see which one fixes the problem. If you don’t have backlights, but you see an image on the screen with the flashlight, that means that your main board and t-con board are good and that you will need to replace the backlight inverter or backlight inverters on your LCD TV and the LED Driver on your LED TV.

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  1. 7 January, 2022, 00:34

    Thanks for watching our TV repair video! Due to YouTube policy changes,
    we are no longer answering tech support questions in the comments
    section. We apologize for the inconvenience. If you need additional tech
    support, please visit or contact your local TV repair shop.
    Good luck and let's fix your TV today!

    Reply this comment
  2. Bernard Nicoll
    Bernard Nicoll 7 January, 2022, 00:34

    I have a sony kdl-xbr9 46inch. The screen has stopped showing a y content. i have audio and can View the remote control menu on the screen. Any vidéo feed (hdmi, av, and ota antenna) dose not show on the screen. Main board issue? Tks.

    Reply this comment
  3. Aklin Francis
    Aklin Francis 7 January, 2022, 00:34

    Have a samsung 40 inch UN40J5200AJ d back lights dim i have audio

    Reply this comment
  4. Deon Paywa
    Deon Paywa 7 January, 2022, 00:34

    Vizio e70u-d3, I have replaced the leds. I did the flashlight test and see an image but then the TV seems to shutdown after a few seconds. The LEDs needed replacement since I’m the past there were a blue hue in some spots on the screen. Since then the TV completely won’t show any backlighting after a few months. Could it be just the power supply?

    Reply this comment
  5. Jaleel Brown
    Jaleel Brown 7 January, 2022, 00:34

    I have a samsung tu8000 55", I came home turned the TV on and I got sound but no image. I turned the light off and tried your flashlight test and I could actually see the menu moving around. Awaiting your professional diagnosis.

    Reply this comment
  6. Morne Momos
    Morne Momos 7 January, 2022, 00:34

    Hi I had Sony klv-v40a10 e32 no blacklight's blink 7time I do what you do nothing happing

    Reply this comment
  7. isaac kabanda
    isaac kabanda 7 January, 2022, 00:34

    my tv has no pic

    Reply this comment
  8. ZeroFuxGiven
    ZeroFuxGiven 7 January, 2022, 00:34

    Apparently my internet line was hit by lightning and our Samsung un50nu6900b was affected.
    Backlight is on sound is there, I replaced the main and power boards but didn't notice a third board.
    The problem persists as of replacing said boards.
    Where would I find the third board as I don't see it?

    Reply this comment
  9. Polaski Singh
    Polaski Singh 7 January, 2022, 00:34

    Tv jvc powers on with picture and sound then it flashes then picture fades

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  10. G the Firm89
    G the Firm89 7 January, 2022, 00:34

    My hitachi goes off to a black screen randomly at any moment with sound still on and light showing tv is on. It can not happen for weeks but then comes back with a vengeance. Surely the backlight ?

    Reply this comment
  11. Elaine Andrews
    Elaine Andrews 7 January, 2022, 00:34

    Can you help me if the roku tv flash on in off in it is on a black screen in still here sound

    Reply this comment
  12. Scott Carlson
    Scott Carlson 7 January, 2022, 00:34

    Had a cheapie $100 tv/monitor used for our security cameras that went dark. Did the tests in the vid, ordered the part and for $14, saved the tv. Thank You!!!!!!!!!!!!!!

    Reply this comment
  13. GBF PANTHER vlog
    GBF PANTHER vlog 7 January, 2022, 00:34

    Invalid format

    Reply this comment
  14. Allison Clarke
    Allison Clarke 7 January, 2022, 00:34

    Hi I have elite led smart tv with blank screen what can I do

    Reply this comment
  15. Aubrey Matlhatlha
    Aubrey Matlhatlha 7 January, 2022, 00:34
  16. hudgeson William mwewa
    hudgeson William mwewa 7 January, 2022, 00:34

    MY TV is on standby light model number Tp.msb.358.pb801

    Reply this comment
  17. Daniel Solomon
    Daniel Solomon 7 January, 2022, 00:34

    Synix 43 inch smart TV,
    Model 43S732F and it's problem is when tv is is turn on, the logo appears for a few seconds and the screen went black.

    Reply this comment
  18. Onik Miha
    Onik Miha 7 January, 2022, 00:34

    My tv is sony wisdom smart tv. I tried to recover the setting and then the display got inversed and color problems. after trying for some while the display is turned black but sounds is ok. How can I solve this?

    Reply this comment
  19. Cindy Edwards
    Cindy Edwards 7 January, 2022, 00:34

    Need help with a Samsung QN75Q60TAFXZA. While watching TV a blue light flashed on a couple of time and then the TV went back to normal. Now the TV will not turn on. It keeps flashing a blue light. it goes from Black screen to a dim blue light and back again. It will not stop. The only want to stop it is to disconnect the power. Any ideas what is the problem?

    Reply this comment
  20. SCOTT DC
    SCOTT DC 7 January, 2022, 00:34

    I have an Insignia 50" led roku tv and the backlights dont work. Did the flashlight test and lcd is making an image. Tested the leds with the jeston led tester power supply and the all of the leds light. I did this while the tv was on and could see the image fine. All 3 branches of the led backlights work and are 32.5 volts. Does the system board tell the power supply to turn on or is the function only on the power supply board? Anyone come across this to find a common issue?

    Reply this comment
  21. PR Wijeratne
    PR Wijeratne 7 January, 2022, 00:34

    Thank you for all the great information.

    Reply this comment
  22. xSnough
    xSnough 7 January, 2022, 00:34

    My tc has audio but no backlight, what do I need to fix this?

    Reply this comment
  23. cheryl rounds
    cheryl rounds 7 January, 2022, 00:34

    Hello, I have a JVC Smart TV model LT- 40C890 my TV would not turn on so I did some steps like unplugging the power cord which did work after a few trys but now it finally came on but has a black screen but with sound. I can't even get to the menu to do a factory reset on the TV as can't see anything? Can anyone help please.

    Reply this comment
  24. diego
    diego 7 January, 2022, 00:34

    technika and faded black screen

    Reply this comment
  25. Roger Kuj
    Roger Kuj 7 January, 2022, 00:34

    I have a model Sharp TV LC-58Q7330U. I have no back lights, no picture, no sound when turned on. I do notice when powering on the power led flashes twice. Any ideas.

    Reply this comment
  26. PhillyRich
    PhillyRich 7 January, 2022, 00:34

    Vizio XVT 373. Will no longer play back a dvd video imgae– audio only. Regular tv signal plays audio and video okay.

    Reply this comment
  27. Greg Lewis
    Greg Lewis 7 January, 2022, 00:34

    My 65 inch Vizio LED tv picture goes off when the sunlight shines on it, but the sound stays on. It works perfect without the sun shining on it. Any recommendations? Thanks for your help.

    Reply this comment
  28. Valu Quest
    Valu Quest 7 January, 2022, 00:34

    I have a Tecnomaster 40 inch LED TV model# LED4002A5W with black screen, but working audio? Do you carry an LED repair kit for this TV? Is the LED driver board integrated into the power board? If so, do you carry this board?

    Reply this comment
  29. adam g
    adam g 7 January, 2022, 00:34

    Hi my tv model is LG 50LN5310. After watching your video i can see an image when i use your flash light test. So like you suggested i want to replace the LED driver. i just need some determining where my LED driver would be on my tv. any and all help is greatly appreciated. thank you

    Reply this comment
  30. Rob Arroyo
    Rob Arroyo 7 January, 2022, 00:34

    I did the flashlight test and deemed it to be an inverter issue. I replaced the inverter a few days ago and the backlight came on. Today the backlight is out again. What else could be the issue?

    Reply this comment
  31. james berry
    james berry 7 January, 2022, 00:34

    what about sound but no back light or screenn when shineing a flashlight

    Reply this comment
  32. HappyRiday
    HappyRiday 7 January, 2022, 00:34

    They forgot to cover when you have no backlights and no menu using the flashlight test. If this happens to you then the backlights are probably broken. I had this on Hisense 50H5C and Hisense 58R6E. I tested the voltage from the power supply board going to the LED lights and saw it was 300V. Voltage going to the LEDs but they aren't working is a no brainer, but you can buy a LED tester to find the specific strip that is bad. LEDs are wired in series like the cheapo xmas tree lights so when one goes out then none of them work. Hope this helps anyone else reading.

    Reply this comment
  33. Don Eugraf
    Don Eugraf 7 January, 2022, 00:34

    Hi, any idea what two slow blinks means on LC-60LE636E? Seems like i have all voltages except backlight

    Reply this comment
  34. Zeedo Shariff
    Zeedo Shariff 7 January, 2022, 00:34

    I have a led tv i have video and audio.but the screen is too dark to she the video. What can be the problem?

    Reply this comment
  35. Juan Pablo Pérez
    Juan Pablo Pérez 7 January, 2022, 00:34

    I have a blaupunkt tv b32a133tchd and the problem is that backlight does not work. Could you help me?

    Reply this comment
  36. Marijuano Pothead
    Marijuano Pothead 7 January, 2022, 00:34

    Does my Vizio E550I-A0 main board have a t-con board and led driver built into it?

    Reply this comment

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