Samsung SCX-4521F Series - Fuser gear melts due to overheating causing Paper Jam.; Paper Empty; Paper Empty without indication

Troubleshooting
Samsung Electronics
Service Manual
6-9
6.3.3 Fuser gear melts due to overheating causing Paper Jam.
• Description
Constant Jam where paper is entering Fuser unit.
Fuser rollers do not turn
Check and Cause Solution
1. Check the Heat Lamp, thermostat and thermistor 1. Use Engine Test Mode to test the Fuser
-THERM ADC 120.
Replace Fuser unit
Replace SMPS or Main PBA as appropriate.
6.3.4 Paper Empty
• Description
Paper Empty is displayed in the LCD panel even when paper is loaded in the cassette.
Check and Cause Solution
1. Deformed paper sensor actuator or faulty sensor.
2. SMPS PBA or Main PBA is defective
3. Faulty cables or connectors.
1. Replace the defective actuator or sensor.
2. Replace the SMPS PBA or MAIN PBA as
appropriate.
6.3.5 Paper Empty without indication
• Description
The paper empty message does not appear in the LCD when the paper cassette is empty.
Check and Cause Solution
1. Deformed paper sensor actuator or faulty sensor.
2. SMPS PBA or Main PBA is defective
.
1. Replace the defective actuator.
2. Replace the SMPS PBA or MAIN PBA as
appropriate