Common outdoor p10 full-color LED display problems repair

1. The whole board is not bright: the board is not connected to the power supply; the input cable is reversed; the input and output are reversed; the positive and negative poles of the power supply are reversed (reverse connection will burn all the ICs on the board). (LED display)

2. The board is not bright and the transmission is normal: the protection circuit is damaged. The solution can be to short-circuit the 4th and 5th pins of the 74HC138. the

3. There is a line that is not lit every three lines: 4953 is damaged (one of them is damaged). the

4. One row lights up every other row: A signal problem, please check whether 74HC245 and 74HC138 have solder joints; you can use a multimeter to measure whether the voltage of pin 1 of 74HC138 is equal to about 2.5V, if so, replace 74HC138; carefully measure the path of the gold needle with ICA signal Happening. the

5. Two lines light up every two lines: B signal problem, please check whether 74HC245 and 74HC138 have solder joints; you can use a multimeter to measure whether the voltage of pin 2 of 74HC138 is equal to about 2.5V, if so, replace 74HC138; carefully measure the gold needle with ICA signal access situation. the

6. The upper half board is normal and the lower half board is all bright or not: if this is the case with the T08A interface, it is necessary to check whether the DR data signal of the lower 8 lines is connected. If it is normal, replace the 74HC245 first. If it is not good, replace the first one. 74HC595.

7. The STB and CLK signals of the upper half board and the lower board are common, and the data is separate (if it is T12 interface data, there is also one). For example, if checking the T08A board, the upper and lower half boards should be inspected separately.

8. If there is one lamp on the board that does not light up: check whether it is soldered or not, and replace the lamp. the

9. There are 4 vertical lights that do not light up: first check whether the 74HC595 has solder joints; second, replace the 74HC595; third, replace the lamp tube. the

10. Among the 4 vertical lights, 3 lights are off and 1 is normal: replace the normal light tube. (led display screen for shop display)

11. If the board displays abnormally from the middle or other positions backward: check the data signal path; replace the last 74HC595 that normally displays the control light; if it is not ruled out, replace the 74HC595 that is controlled by the first abnormal display light. Each 74HC595 controls 8 dots wide * 4 dots high lamp. The 74HC595 is connected in series with the DR data signal, that is, the DR signal is connected from the 14th pin of the 74HC595 to the 9th pin and then connected to the 14th pin of the next 74HC595 to the last 74HC595. For example, the DR data of this board is from the gold pin to the 74HC345 After zooming in, go to UR1 to UR2 to UR3 until UR8 and then to the output gold needle. the

12. Sometimes in the process of debugging the whole screen, the display from the front module to the rear module is abnormal. The general fault is that the cable is not plugged in or damaged; you can also use a slightly longer cable to connect the module being checked below. Plug the cable into the abnormal module above to see how it is displayed. You can also connect the output of the normal module above the abnormal part to the next row of modules to see how the display shows, to determine which module has a problem. .