Canon CLBR 460ps Service Manual page 296

CHAPTER 4
replace the upper thermistor.
2) Abnormal lower thermistor
Action: Turn the power switch OFF and remove the fixing unit. Measure the resistance
between the fixing unit connector J82-A4 (THRL) and J82-A3 (GND). If it is not
between 430kΩ to 310kΩ (room temperature 25°C), check the wire between the fix-
ing unit connector J82 and the lower thermistor connector J85. If it is normal,
replace the lower thermistor.
3) Defective power supply unit
Action: Replace the power supply unit.
4) Defective DC controller PCB
Action: Replace the DC controller PCB.
[ 6-13 ] "SERVICE CALL NOTE # D6" Fixing unit malfunction (broken heater wire)
<Possible causes>
1) Upper fixing heater wire/upper thermoswitch wire is broken
Action: Remove the fixing unit from the printer. If there is no continuity between the fixing
unit connector J82-2 (HTH) and J82-3 (HTUC), check the upper fixing heater and
the upper thermoswitch, and replace the defective parts.
2) Lower fixing heater wire/lower thermoswitch wire is broken
Action: Remove the fixing unit from the printer. If there is no continuity between the fixing
unit connector J82-2 (HTH) and J82-4 (HTLC), check the lower fixing heater and the
lower thermoswitch, and replace the defective parts.
3) Poor contact in connectors
Action: Reconnect the DC controller PCB connector J1012 and the fixing unit connector
J82, and the power supply unit connectors J1 and J2 correctly.
4) Defective power supply unit
Action: Replace the power supply unit.
5) Defective DC controller PCB
Action: Replace the DC controller PCB.
[ 6-14 ] "SERVICE CALL NOTE # E1" Developing rotary malfunction
<Possible causes>
1) Claw for releasing developing rotary break is damaged
Action: Check the claw on the cartridge door for releasing developing rotary break. Replace
the cartridge door if the claw is damaged.
2) Open the cartridge door and turn the power switch ON while holding down the developing
rotary break release lever and the door switch. If the developing rotary does not rotate, go
to step 9).
3) Damaged rotary drive unit
Action: Replace any drive gears in the rotary drive unit if damaged or worn.
4) Damaged developing rotary position sensor flag
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