Frequent failures of vehicle-mounted LED advertising screens include black screens, screen flickering, and advertising failures. Therefore, it is necessary for maintenance personnel to understand what causes such phenomena to facilitate troubleshooting.
1. The car LED advertising screen is black
1. The power supply is abnormal, and the normal working voltage of the screen is DC 9-40V
2. When the power supply is normal, the screen will be blank, disassemble the display screen, and observe whether the indicator light of the control system is on. If the indicator light does not occur, please check the input and output voltage of the power supply with a multimeter. Normally, the output voltage of the power supply is 4.5V. To 5.5V.
3. If the output voltage of the power supply is normal and the indicator light of the control system is off, it means the system is faulty. If only the system power indicator light is always on, the status indicator light is off (normally the system has the power indicator light always on, and the working indicator light flashes. ).
4. If the power indicator light is always on and the system indicator is flashing normally, it means that the control system hardware is normal. In this case, use the test software to check whether the system is set to "On time calibration" (if the system is set to light on calibration You need to reset the system) or re-upgrade the control card, and check whether the power supply of the unit board is normal (check whether the power supply of the unit board has a false welding).
Second, the car LED advertising screen is garbled or displayed abnormally
1. Fuzzy display of the vehicle-mounted LED screen indicates a hardware failure of the unit board. Common failures include chip management false welding (one column does not light up, a small piece does not light up), chip burnout (the second half does not light up), and lamp bead burnout (one row often does not light up). Bright or one can't wait)
2. If one column is not bright, please repair the corresponding chip management, a small part is not bright and need to replace the corresponding chip (column control chip 5020 or 74H595, row control chip 4953)
3. The on-board LED advertising screen displays normally, but the advertisement fails to be sent
1. First check the communication line, whether the plug of the communication machine is off or unplugged, if so, please connect it back. (There are two connectors between the GPS and the display screen, one is connected to the GPS, and the other is the external communication line of the LED display. There is a joint at the centimeter)
3. If the connectors are all connected, try to unplug the communication connector at the display screen, check whether the copper plate of the connector is in poor contact or the copper plate has been inserted incorrectly, and then try to correct it. (In this case, the advertisement has been displayed, but the platform shows that it is sending, indicating that the LED feedback line (TXD) is faulty. Please check whether the connector is properly connected).
4. If the connector at the display has been connected and it is judged that the display communication is normal, please check whether the connector at the GPS is disconnected or whether the communication line between the display and the GPS is short-circuited, etc.
5. If it is judged that the display is a problem, disassemble the display and check whether the communication line of the system has fallen off (the display is relatively rare). If the communication line is connected normally, it is judged that the communication line chip (232) of the system is faulty. The communication chip needs to be replaced.
