1, control card failure;
2. The line from the computer USB port to the control card is out of order;
3. There is something wrong with the LED display control software on the computer (this is relatively small and can be solved remotely).
So it is probably caused by the first two reasons. If you want to rule it out, you can do so.
1, you need a shorter control cable (make sure it is good);
2. Install LED display control software on the notebook computer;
3. Connect the short wire next to the LED screen to the laptop for testing. If the problem is eliminated, the fault may be the line;
4. If the problem still exists, the fault is probably the control card;
5. If you want to continue the test, you need to have a spare control card and change it yourself.