In using LED displays, you will be forced to experience issues in running the device that can frustrate you and cost you money at the same time. You might need to go to an LED screen repair shop to have your device checked.

If you want to try solving whatever issue your LED screen has, you can do so as long as you’re armed with the appropriate equipment and tools and the right knowledge. There’s nothing wrong with trying your luck in fixing your LED screen. You may come out of the experience wiser and with more knowledge about troubleshooting your display and the LED screen repairs you can do with it 

LED Screen repair of Module Issues

LED display screen module repair, IC, lamps repair outdoor, indoor P10, P8, P6, P5, P4.81, P3.9, P2

To repair LED screens with module issues, there are different ways you can approach this problem based on what you can see on your LED screen. Identifying the issues of your display is the first step in possibly repairing it. For module problems, here are some of the steps to troubleshoot your display based on what you can see on the screen. 

Module Not Displaying

If your module doesn’t display anything, here are some of the possible issues with it and the LED screen repair recommendations you can do. 

  • Problem with the signal line – Look into the signal line status of your module, including the interference. Once you notice that in the signal line, there’s the first abnormal point, replace it. 
  • Power cord issues – Look at the first module you see some issues, check the power cord connection. If that’s not the issue, consider replacing the power cord. 
  • In addition, if the entire LED module does not light up, it may be that the amplification IC (such as 74HC245) on the back of the LED module is faulty. We can check or replace it.

If nothing changes, try plugging the signal and power cord in and out several times. 

Single dead lamp by weak solder or open circuit

How to repair LED screens with dead pixels? Dead pixels refer to when pixels become defective that they don’t work anymore. While some dead pixel issues are so minute that you hardly see any sign on the display, some are so noticeable that you won’t have any choice but to work on them. 

Technically, dealing with dead pixels won’t point towards LED screen repairs. Most of the time instead of reviving the dead pixels, many recommend just replacing them with new ones. 

Whether you have an LED screen with a front or rear maintenance design, you need to follow the same steps when working on dead pixels. Open the case (front or rear) using a screwdriver, remove the LED module that needs maintenance, and then install it the same way. The difficult part is the actual maintenance where you’ll need the skills of an expert.

Lamp bead structure

A pixel lamp bead is composed of four lamp pins: red (R), green (G), blue (B), and “+”. When we test the red, green, blue, and white colors of the LED module, different lamp pin problems will show different appearances, If the LED display has a single pixel that’s darkening and dimming, check out these LED pixel repair tips. 

R,G,B Lamp
R,G,B Lamp

Phenomenon and solution

  1. The entire pixel does not light up
    1.1. The problem pixel “+” is weakly soldered or disconnected;
    1.2. The problem pixels “R”, “G” and “B” are all weakly soldered or broken.
    It is necessary to re-solder or reconnect the lamp pins that are weakly soldered or disconnected.
  2. Only a single color of red, green, or blue is missing. Only the color lamp pin corresponding to the problem pixel is soldered or disconnected. Just repair the problem part.
  3. Two colors are missing. The lamp pin of the problematic color is welded or broken. Just repair it.

Test Methods

  • Check if the LED lamp beads are operating normally. Use a multimeter and troubleshoot the beads and their performance. 
  • Identify the LED’s positive and negative poles and connect them to their corresponding probes. You can identify them with their colors, where the positive pole should always be connected to the color black while the negative pole should be linked to the red probe.
  • Check if the light beads are normally working, which is often determined once the LED light turns on. If not, replacing the new LED lamp is recommended. 

Faulty LED Lamp Beads

Some module issues can be due to faulty LED lamp beads. In such cases, follow these simple LED screen repair steps. 

  • Get a tweezer and remove the gel found on the LEDs. Make sure that the LED beads’ pins are shown.
  • Using a tool, clamp the lamp bead. Prepare a soldering iron and solder it. Make sure to do it fast to avoid damaging the lamp beads.

Multiple lamps defective

Sometimes maybe you will find that the colors displayed by multiple lamp beads on the LED module are different, which is much worse than the poor display effect of a single lamp bead.

It may be that the pin of the driver IC that controls a single color is soldered or the circuit is open, causing the color to be missing;
Solution: Repair welding or replace with a new IC

The circuit of the lamp bead that has the problem is disconnected, causing the signal transmission of the lamp bead connected to it behind to be unable to pass, so this lamp bead and the lamp beads connected in series will lose color.

Missing Color Blocks

The driver IC is one of the important components of the LED module. It is attached to the PCB board and controls the red, green, and blue lamp beads respectively. One pin of an IC usually controls 16 lamp beads (if there is a problem with a single pin, 16 lamps will not light up or be abnormal). One drive IC has 16 pins to control 16×16=256 lamp beads. If there is a problem with the IC, 16×16 lamp beads will display abnormally.

IC structure
IC structure

If there are color blocks that are missing on the display, here are the steps to follow for the LED screen repair:

  • Look at the module’s connections, specifically the power and signal lines
  • Consider the idea that the color block’s IC has short-circuited and needs replacement 
  • Get a new LED module

Column/s Not Displaying

In this case, one or several columns are not lighting up or showing on the display. Look at the LED module and find the pin responsible for the affected column. Pay attention to the IC driver’s output terminal and make sure that it is properly connected. 

Only Column Lighting Up

If only one column is working and lighting up, here are some of the go-to LED screen repair steps to consider:

  • Check for any signs of short circuits, specifically in the areas that control the affected column, including in the power supply’s positive charge 
  • Consider getting a new IC driver

Troubleshooting & LED Screen Repair Suggestions

For an LED display not working, troubleshooting remains the best first step if you want to find out what’s wrong with your LED screen. Here are some of the issues you may encounter and the LED repair suggestions you can try out to fix them.

Display Not Working with Green Flashes

When you have a display screen that’s not working along with green flashes on the sending card, here are the areas you’ll need to check out:

  • Normal power in the panel
  • Properly connected signal wiring
  • Receiving Card (Power should be 5 to 5.2 V): No power or low voltage power 
  • Possible sending card replacement 

Display Not Working without Green Flashes

For a display that’s not working and comes without green flashes, here are some of the troubleshooting steps you can consider for the LED screen repair:

  • Look at the HDMI or DVI wiring if it’s properly linked
  • The graphic control panel needs to be extended or copy mode
  • Try reinserting the sending card
  • Replacement for the sending card may be needed

No Large Screen System Prompt

If there’s a prompt shown on the screen saying that there’s no large screen system found at the startup, here are some considerations you can make:

  • Look at the serial wiring if it is not connected properly
  • Try linking the screen to another computer
  • Uninstall old software and install a new one
  • Consider the possibility of replacing the sending card or serial line

Some LED Display Not Showing

For some of the LED displays that are not showing anything, there are two possible reasons for it. The power supply may not be working properly or the power cord needs to be reconnected. 

Entire LED Display Not Showing

In case the entire LED screen is not showing anything, you will need to check out all its connections. Look into the main power and network wiring if they are properly connected. If there are no problems with that, a new collection card may be needed for the entire ensemble. 

If using a synchronized system you need to check that copy mode is used and that the video processor selects the correct video source signal.

Multiple cabinets do not light up

Check whether the network cable and power supply of the box that does not light up are working properly. This can usually be solved by replacing or unplugging the network cable, and checking and replacing the power supply of the box where the problem occurs.

A single cabinet not showing

  • It may be a problem with the receiving card of this cabinet. Just replace the receiving card.
  • It may also be that the program file is lost and the program file reappears.
  • It is also possible that the power supply is not supplying power to the receiving card. You can connect the power supply cable or replace the problem power supply.

Multiple LED modules in the cabinet do not display

Usually, the input flat cable for the module that does not display at the beginning is loose or broken. Solution: Reconnect or change the flat cable to check if the problem is solved.

Winking/Shaking Display

If the display is winking or shaking, here are some of the LED screen repair steps you can take:

  • See if the sending and receiving cards are properly operating (Look for a green light that shows there’s a signal)
  • Look at the DVI cable if it’s properly connected
  • Inspect if the signal cable and cabinets are appropriately linked. If not, re-plug it. If that still doesn’t work, replace the cable. 

The Same Content for All Displays

When all of the displays are showing the same content, you might need to reset the connection file. Check the network cable and inspect if the indicator light turns on when the computer is sending information to the display

Displays Not Synchronous

LED displays are regarded as high-end because they can be programmed to show specific images that are different from each other to paint an even bigger and grander image. If they are not synchronized according to how they are programmed, look at the DVI card setting. Make sure that it shows duplicate under the multiple display mode. 

Low Brightness & Blurry Image

When you encounter blurry images on your display and significantly low brightness levels, work on the LED screen repair in the following ways:

  • Find out your LED screen’s minimum brightness and set it at 80 levels higher
  • Restore your sending card to its default settings

Image Ghosting

Image ghosting refers to when there’s a trail of pixels that can be seen behind the moving images on the screen. It often happens with fast-paced movements shown on the display. Along with the whole picture shaking, you can deal with these issues through these solutions:

  • Look for the communication line and insert it again
  • Strengthen your DVI cable
  • Replace the sending card

Troubleshooting the receiving card indicator light for led screen repair

Indicator lightColorStatusIllustrate
Running indicator lightGreenFlashes 1 time per secondWorks fine,the receiving cards aren’t issues
Flashes every 3 secondsNetwork cable problem
Flashes 3 times in 0.5 secondsThe network cable is OK, but there is a problem with the video source.
Flashes once within 0.2 secondsLoader files failed, backup status
Flashes 8 times within 0.5 secondsNetwork port redundancy switch, backup takes effect
Power  indicator lightRedAlways onPower is OK


When you consider doing your own LED screen repairs, you can save money and learn more about managing displays in the process. The LED screen repair cost can be expensive so when you have the time and resources, you can learn about how to properly manage and maintain your LED displays. However, you can always ask the help of experts if you don’t have the time to spare in your busy schedule.

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