Normal malfuntion and obviation of LED Display

A. Black screen

1. Check the power is on.

2. Check the UTP is well connected. (Synchronize)

3. Synchronize screen, the glitter.

4. Display screen is well protected, or display is black or blue.

B. The whole PCB is black

1. Several PCB is not lightened in the horizontal, check the connection between normal and abnormal. Or the IC245 is working regularly.

2. Several PCB is not lightened in the vertical, check the power supply is working regular.

C. The last line of PCB is not lightened

1. Check the pin 4953 is well connected.

2. Check the 138 works in order.

3. Check if the 4953 is hot or burned.

4. Check the 4953 is high level.

5. Check if the control pin of 138 and 4953 is connected.

D. PCB is not lightened

1. Check if 595 is working in order.

2. Check concerned pin of the upper and nether module connect well.

3. Check pin of output and module connect well.

E. PCB lacks of color

1. Check if the normal output pin of595 and abnormal is well connected.