The brightness of the LED fill light is dim or it fails to turn on.
1. The LED light is burned out or the cable is damaged, and the LED fill light needs to be replaced;
2. The AP mainboard is burned out and needs to be replaced;
3. The MC-AP connection is disrupted. Depending on the location of the problem, the MC-AP connecting cable or related boards may need to be replaced.
When disassembling the connection cable on the printer, the printer should not be connected to power.
If the fault occurs after the user modifies or replaces the fill light, then the control circuit of the fill light on the AP board may be damaged. The figures below are a detailed view of the connector of the LED fill light on the AP board.
(1) If a lamp with a working voltage of 5V and a working current greater than 0.3A is installed, the 0R resistor and/or the magnetic bead may be damaged. The general fault cause is an open circuit or an increase in resistance, which causes the current path to be interrupted and the lamp cannot be switched on or off.
(2) If a voltage above 5V is injected into the connector, the ESD may have been overheated and damaged. The issue is likely a short circuit, and there will be a burnt mark on the ESD surface.
(1) Before dismantling the printer for inspection, you can do a simple pre-inspection: Power on the printer, turn on the LED light, then remove the fixing tape of the AP-MC connecting cable, shake the entire cable, and check whether the LED light will return to normal or not. If it can return to normal, it means that there is poor contact and cable contacts need to be checked.
(2) Refer to the relevant steps of the MC-AP cable, find the connectors of the cable on the AP board and MC board, mainly to confirm the connector and connecting cable between MC and AP; see whether there is any disconnection, falling off, or other poor contact problems; and confirm that the plugs and seats are normal and without damage.
(3) Users who have testing conditions can keep the MC-AP connected after loosening the AP main board and starting the printer to test the output voltage of the 5V pin on the AP board to confirm whether the voltage is normal.
If the printer functions well except for the LED fill light turn on failure, you can try exchanging the LED fill light if there are more than one P1P printers at home.
If there are no multiple printers, directly purchase or apply for a new the LED fill light for for replacement.
If the printer is accompanied by other faults besides the abnormal LED fill light, please solve the problem in conjunction with the troubleshooting guidelines for other faults.