VI. MALFUNCTION STATUS TROUBLESHOOTING
If the factor of the malfunction is identified as “malfunction status troubleshooting” by the mal-
function diagnosis flowchart (Figure 4-1-1), execute the followings and mend the malfunction.
VI-1. "10.1 ERROR FUSER CALL FOR SERVICE"
Fixing unit failure (abnormal low temperature)
"10.2 ERROR FUSER CALL FOR SERVICE"
Fixing unit failure (abnormal Warm-up)
<Possible causes>
1. The rated voltage of the fixing unit installed in the printer differs from the line voltage.
Action: Replace the fixing unit.
2. The thermistor is dirty.
Action: If the thermistor contact area of the upper fixing roller is dirty, clean it.
3. The thermistor is not installed correctly.
Action: If the thermistor is not evenly contacting the upper fixing roller, re-install the ther-
mistor correctly.
4. The thermistor wire is broken.
Action: Turn the power OFF and remove the fixing unit. Measure the resistance between
the fixing unit connector J50B-5 (FSRTH) and J50B-4 (GNDTH). If the resistance
is not between about 190kand 290k(room temperature of 25°C), check the
wiring from connector J222 on the DC controller PCB to the thermistor. If it is nor-
mal, replace the thermistor.
5. The main heater wire is broken.
Action: Remove the fixing unit. If there is no continuity between the fixing unit connector
J50-3 (FSRN1: the upper right terminal of the left connector) and J51-5 (FSRN2: the
upper right terminal of the right connector), replace the main heater.
6. The sub heater wire is broken.
Action: Remove the fixing unit. If there is no continuity between the fixing unit connector
J50-4 (FSRL1: the lower right terminal of the left connector) and J51-6 (FSRL2: the
lower right terminal of the right connector), replace the sub heater.
7. The thermoswitch is open.
Action: Remove the fixing unit and wiring cover. If there is no continuity between ther-
moswitch terminals, replace the thermoswitch.
8. The fixing unit drive circuit is defective.
Action: Replace the power supply unit.
9. The DC controller PCB is defective.
Action: Replace the DC controller PCB.
4 - 21
CHAPTER 4