1. Misregistration
Cause: Uneven gripping force of the paper feeder, worn gripper pads, radial runout of the cam roller (error exceeding 0.02mm), or misaligned screen.
Handling: Check the paper feeder pressure, adjust the tension spring compression, or replace worn gripper pads (plastic gripper pads have a lifespan of approximately six months).
Replace the cam roller and calibrate the radial runout.
2. Electrical System Fault
Symptom: Motor fails to start, speed regulation is abnormal, contactor malfunctions.
Troubleshooting: Check the coils of the intermediate relays (such as KA2 and KA3) for burnout and poor contact.
Test the speed potentiometer (WT2) and electromagnetic speed controller (such as EA2) for proper function.
3. Abnormal Paper Feed
Cause: Clutch (YA02) coil burns out, the sheet gap control motor is not touching ground, or the relay (KA01) is faulty. Handling: Replace damaged parts, reset the paper feed button (SB03), or adjust the position of the electric teeth.
4. Press/release failure
Fault: Burned-out solenoid (YA4) coil, stuck relay (KA9), or misaligned sheet detector (SQ9).
Solution: Repair or replace the solenoid and calibrate the detector position.
5. Mechanical jam or unstable movement
Possible causes: Bearing wear (clearance exceeding 0.1mm), insufficient lubrication, or loose drive belt.
Maintenance recommendations: Regularly clean the paper guide rollers, add grease, and check the parallelism of the rollers.
