Solution

Step 1: Please contact customer service staff to obtain the mandatory firmware update file(s)

Step 2: Copy the files to the outermost directory of the USB

Step 3: Turn off the power of the LED display and plug in the USB

Step 4: Press the power button to turn on the display, and immediately press the Menu button repeatedly until the update FW screen appears, which means that a force FW update is being performed. If the FW screen does not appear, press and hold the "Standby" button on the unit instead of the Menu button.

At this time, please do not hard restart or turn off the power, and wait for the system to Restart by itself.