How to Maintenance Small Pixel Pitch LED Display? (Part 3)

5. the whole led screen does not shine, dark light. Inspection:

(1) Visual test power supply cable, 16P cable between the unit board and the power module indicator is normal.

(2) with a multimeter to measure the cell board with or without normal voltage, and then measure the power module voltage output is normal, if not, then determine the power module is bad.

(3) Measure the power module voltage is low, adjust the fine-tuning (power module near the indicator at the fine-tuning) so that the voltage reaches the standard.

6. the cell plate appears cell (cell plate is divided into upper and lower district) no red or no green. check Maintenance:

(1) visual fault corresponding to the integrated circuit, 16P cable with or without solder joint, open circuit and 5V power supply is normal (can be directly used good 16P cable replacement).

(2) 16P cable between the unit board (16P cable 9,11 feet for the red signal, 10,12 feet for the green signal) and the front of the cell board output (Judgment: take a long 16P cable cross-exchange connection appears normal, then determine the back of the problem; the other hand, in front of a problem) is normal.

7. the cell plate area (cell plate up and down two cells) in the middle of the upper and lower two modules are short of red, lack of green or from a normal start to the last are missing red, Lack of green. Inspection and maintenance:

(1) visual test unit on the board corresponding to the failure of integrated circuits such as driver IC MBI5124 whether Weld, short circuit, open circuit; If so, the pin welding.

(2) detection of 5V power supply is normal.

8. there is no regular phenomenon of led module, inspection and maintenance:

(1) visual unit board connection line, 16P cable and some other circuits are normal. (16P is divided into 13 groups, of which 16 feet for the clock, 7 feet OE side, 14 feet for the latch clock).

(2) the input is normal, and if so, then the clock signal, 5124 latch clock, 138EN end of the signal In front of the output of the unit board has a problem, if not, then check the signal sent to the HC245 after the drive, if not, then determine the HC245 bad, with the same model HC245 replaced.

(3) Detection HC595 11 feet, 12 feet, the input and HC138 4 feet, 5 feet input with or without short circuit, open circuit, Weld, whether their respective voltage is normal, if not, then determine the corresponding MBI5124 / SC16016, HC138 bad, with the same type of integrated circuit replaced.

9. a whole screen does not shine (black screen) synchronization screen, inspection and maintenance:

(1) detecting whether the power supply is energized.

(2) check whether the communication line connected, first check the sending card, the green light is flashing, such as no flicker, check whether the card is plugged in.

(3) If there is no blinking green light, please check whether the network cable is loose, if not, whether the crystal head is pressed well, such as good, may be the cable quality problems.

(4) computer monitors are protected, or the led display shows the field is black or pure blue.