Service manual
Table Of Contents
- COVER
- CAUTION
- Safety precautions
- CONTENTS
- 1-1 Specifications
- 1-2 Handling Precautions
- 1-3 Installation
- 1-4 Maintenance mode
- 1-5 Trouble Shooting
- 1-5-1 Paper misfeed detection
- 1-5-2 Self-diagnosis
- 1-5-3 Image formation problems
- (1) No image appears (entirely white).
- (2) No image appears (entirely black).
- (3) Image is too light.
- (4) Background is visible.
- (5) A white line appears longitudinally.
- (6) A black line appears longitudinally.
- (7) A black line appears laterally.
- (8) One side of the copy image is darker than the other.
- (9) Black dots appear on the image.
- (10)Image is blurred.
- (11)The leading edge of the image is consistently misaligned with the original.
- (12)The leading edge of the image is sporadically misaligned with the original.
- (13)Paper creases.
- (14)Offset occurs.
- (15)Image is partly missing.
- (16)Fixing is poor.
- (17)Image is out of focus.
- (18)Image center does not align with the original center.
- (19)Image is not square.
- (20)Image contrast is low (carrier scattering).
- 1-5-4 Electrical problems
- (1) The machine does not operate when the main switch is turned on
- (2) The drive motor does not operate when (C200)
- (3) The scanner motor does not operate.
- (4) The toner feed motor does not operate
- (5) Cooling fan motor 1 does not operate
- (6) Cooling fan motor 2 does not operate
- (7) Cooling fan motor 3 does not operate
- (8) The drawer motor does not operate
- (9) The registration clutch does not operate
- (10) The upper paper feed clutch does not operate
- (11) The lower paper clutch does not operate
- (12) Paper feed clutch (ST) 1 does not operate
- (13) Paper feed clutch (ST) 2 does not operate
- (14) The bypass paper feed clutch does not operate
- (15) The cleaning lamp does not turn on
- (16) The exposure lamp does not turn on
- (17) The exposure lamp does not turn off
- (18) The fixing heater does not turn on (C610)
- (19) The fixing heater does not turn off
- (20) Main charging is not performed
- (21) Transfer charging is not performed
- (22) No developing bias is output
- (23) The original size is not detected
- (24) The original size is not detected correctly
- (25) The message requesting papaer to be loaded is shown when paper is present
- (26) The message requesting papaer to be loaded is shown when paper is present in the upper drawer
- (27) The message requesting papaer to be loaded is shown when paper is present in the lower drawer
- (28) The size of paper in the upper drawer is not displayed correctly
- (28) The size of paper in the upper drawer is not displayed correctly
- (29) The size of paper in the lower drawer is not displayed correctly
- (30) The printing width of the paper on the bypass is not detected correctly
- (31) A paper jam in the paper feed, paper conveying or fixing section is indicated when the main switch is turned on
- (32) The message requesting covers to be closed is displayed when the front cover, paper conveying unit and lower drawer left
- (33) Others
- 1-5-5 Mechanical problems
- 1-6 Assembly and disassembly
- 1-6-1 Precautions for assembly and disassembly
- 1-6-2 Paper feed section
- (1) Detaching and refitting the upper and lower paper feed pulleys
- (2) Detaching and refitting the bypass paper feed pulley
- (3) Detaching and refitting the left registration cleaner assembly
- (4) Detaching and refitting the right registration cleaner assembly
- (5) Detaching and refitting the bypass paper width switch
- (6) Adjustment after roller and clutch replacement
- 1-6-3 Optical section
- (1) Detaching and refitting the exposure lamp
- (2) Detaching and refitting the scanner wires
- (3) Detaching and refitting the laser scanner unit
- (4) Adjusting the skew and vertical shifting of the laser scanner unit
- (5) Detaching and refitting the ISU (reference)
- (6) Adjusting the position of the ISU (reference)
- (7) Adjusting the longitudinal squareness (reference)
- (8) Adjusting magnification of the scanner in the main scanning direction
- (9) Adjusting magnification of the scanner in the auxiliary scanning direction
- (10) Adjusting the scanner leading edge registration
- (11)Adjusting the scanner center line
- (12) Adjusting the margins for scanning an original on the contact glass
- 1-6-4 Main charging section
- 1-6-5 Drum section
- 1-6-6 Developing section
- 1-6-7 Transfer section
- 1-6-8 Cleaning section
- 1-6-9 Fixing section
- 1-7 Requirements on PCB Replacement
- 2-1 Electrical Parts Layout
- 2-2 Electrical parts layout
- 2-3 Operation of the PCBs
- 2-4 Appendixes

2AV/X
1-5-15
Code Contents
Remarks
Causes Check procedures/corrective measures
1-5
C620
C630
C710
C730
Abnormally low fixing unit
thermistor temperature
• The fixing temperature remains below
100˚C/212˚F for 10 s during copying.
Abnormally high fixing unit
thermistor temperature
• The fixing temperature exceeds
240˚C/464˚F for 10 s.
Toner sensor problem
• The sensor output voltage is outside
the range of 0.5 to 4.5 V during toner
control.
• The toner sensor control voltage
cannot be set within the setting range
when maintenance item U130 is run.
Broken external temperature
thermistor wire
• The input voltage is above 4.5 V.
Fixing heater
installed
incorrectly.
Broken fixing
heater wire.
Poor contact in
the fixing unit
thermistor
connector
terminals.
Broken fixing unit
thermistor wire.
Fixing unit
thermistor
installed
incorrectly.
Fixing unit
thermostat
triggered.
Shorted fixing unit
thermistor.
Broken fixing
heater control
circuit on the
power source
PCB.
Defective toner
sensor.
Poor contact of
the toner sensor
connector
terminals.
Developer
problem.
Poor contact of
the humidity
sensor PCB
connector
terminals.
Defective external
temperature
thermistor.
Check and reinstall if necessary.
Check for continuity. If none, replace fixing
heater.
Check the connection of connector CN12
on the main PCB and the continuity across
the connector terminals. Remedy or
replace if necessary.
Measure the resistance. If it is ∞ Ω, replace
the fixing unit thermistor.
Check and reinstall if necessary.
Check for continuity. If none, replace the
fixing unit thermostat. Check the operation
of the cooling fan and repair if necessary.
Measure the resistance. If it is 0 Ω, replace
the fixing unit thermistor.
Replace the power source PCB.
Replace the toner sensor.
Reinsert the connector. Also check for
continuity within the connector cable. If
none, repair or replace the cable.
Replace the developer.
Reinsert the connector. Also check for
continuity within the connector cable. If
none, repair or replace the cable.
Replace the humidity sensor PCB.










