Common faults and solutions guide for LED display module

After using the LED display screen for a period of time, it is inevitable that there will be broken lights, partial black screens and other phenomena. Generally, it is due to problems with the LED module. The following are 5 common solutions to simple LED module failures.

1, LED module does not light up continuously or is abnormal

Fault phenomenon: The display screen shows a large area of black screen.

Solution steps:

(1) Check the wiring and power cord of the first abnormal module in the signal direction to ensure good contact.

(2)If the module does not have LED light, it may be a power input fault: use a multimeter to check the power part.

(3)If there are color highlights (color confusion), it may be due to abnormal signal input: check the input end of the first abnormal module cable and perform multiple plug and unplug tests; If it is ineffective, replace the cable with a new one.

2, Single module does not light up

Fault phenomenon: Single module black screen, no display.

Solution steps:

Check the power supply of the module: Check if the power socket on the module is loose.

If the module color is chaotic but there is signal input (the screen part is normal), it is mostly due to poor contact of the ribbon cable: re plug and unplug the ribbon cable, or replace the tested ribbon cable.

If the problem persists after replacing the wiring, check if the PCB board interface and pins are damaged.

3, Single light failure detection

Fault phenomenon: dead light, incomplete and blurry image display.

Testing method:

Measure the LED beads with a multimeter resistor in X1 range:

Pointer multimeter: connect the black probe to the positive terminal and the red probe to the negative terminal;

Digital multimeter: Connect the black probe to the negative terminal and the red probe to the positive terminal.

If the LED lights up, the LED beads are normal; If it does not light up and the light bulb is damaged, it needs to be replaced according to item 5.

4, Maintenance of LED bad points (out of control points)

Fault phenomenon: Single lamp inspection confirms LED damage, choose maintenance method according to requirements.

resolvent:

(1) Positive maintenance

Use the corresponding screwdriver to remove the fixing screws of the front face mask (keep the screws), and remove the lower face mask;

Replace the lamp beads according to the method in item 5, and seal the adhesive after completion;

Restore the mask and tighten the screws (be careful not to press down on the LED beads), and remove any remaining adhesive on the surface of the LED.

(2) Back maintenance

Remove the screws from the back with a screwdriver (keep the screws), unplug the signal cable (do not unplug the power cord to prevent accidents);

Carefully remove the module from the sheet metal hole and move it to the back of the box;

Refer to the front maintenance steps to replace the lamp beads or repair other components.

5, LED bead replacement process

Dismantling of damaged LED beads: Use tweezers to remove the adhesive around the damaged LED beads and expose the pins; Use tweezers to hold the light bulb in your right hand, and use a soldering iron (at a temperature of about 40 ℃ to avoid damaging the LED due to high temperature) to melt the solder in your left hand (stay for no more than 3 seconds, cool down before trying again). Use tweezers to remove the damaged light bulb.

Install new LED beads:

The long leg is the positive pole and the short leg is the negative pole, which are inserted into the "square hole" (positive pole) and "circular hole" (negative pole) of the PCB board respectively;

Dip a soldering iron into the solder, fix the direction of the lamp bead, and solder the connection.

Sealing gel: Seal the LED with the same type of gel to ensure stability.

Tip: It is recommended to wear anti-static gloves during operation to avoid damage to components caused by static electricity; After replacement, it is necessary to test the display effect of the module to ensure troubleshooting.