symptom

After the paper tray 1 is placed, the paper tray lifts the motor action, and the SP5804-038 output checks that the lift motor rotates normally.

the reason

1. Paper size sensor is defective

2. BICU board is bad

solution

This machine detects the switch 1 of the paper size sensor as a tray. 0: Advance 1: Not advanced

SP5803-001 detects the paper detection data of 1 paper tray, and finds that the reading of switch 1 is always 1 when the paper tray is advanced, and the fault is eliminated after replacing the sensor.