Xerox Phaser 3450, Service Manual, Page: 88 / 155

7-13
TROUBLESHOOTING
Service Manual
7.3 The cause and solution of the malfunction
7.3.1 Fuser Error
• Description
A message "Open fuser/Over heat/Low heat' is displayed in a LCD panel.
Check and Cause Solution
1. Check whether a thermostat, AC wire, and heat
lamp are open or not.
2. Check whether a thermistor is open or not.
3. Heat lamp ON/OFF test
4. It could not operate due to a gear of a fuser is
melted.
1. Replace the fuser if a thermostat is open.
2. Replace the fuser if a thermistor sensor is
located deep inside of a sponge.
3. Check whether the overheat mode circuit
operates normally or not.
4. Replace the fuser.
7.3.2 LSU Error
• Description
A message "PMOTOR ERROR/HSYNC ERROR' is displayed in a LCD panel.
Check and Cause Solution
1. Check whether the LSU connector is disconnected or
not.
2. Check whether the LSU motor is rotating or not.
3. Check the HSYNC signal.
- Replace a LSU
- Replace a main board if the same error occurs again
after replacing a LSU.