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
2-1-12
2-1
(2) Toner density detection by the toner sensor
The toner sensor (TNS) detects the toner density. As the developer passes by the sensor section of the toner sensor, the
toner sensor detects the ratio of toner to carrier in the developer and converts it into a voltage. When more toner is used,
the ratio of toner to carrier decreases and the toner sensor output voltage increases. When the ratio drops below the
specified value, the increase in toner sensor output voltage triggers toner replenishing. When toner is added and the ratio
of toner to carrier returns to normal, the toner sensor output voltage drops to the point where toner replenishing stops.
(3) Toner density control
Toner sensor
output voltage (V)
Toner empty
detection level
Toner feed start level
Copying
Toner being replenished message
(forced toner feed)
Toner request message
(Toner cartridge and
waste toner tank to be replaced.)
180 s
Figure 2-1-16 Toner density control
a: If the toner sensor output voltage exceeds the toner feed start level 3 s after the drive motor (DM) has turned on (end
of toner empty detection inhibit time), the toner feed motor (TFM) turns on to replenish toner.
b: As toner is replenished, the toner sensor output voltage falls until it drops below the toner feed stop level and
replenishing stops.
c: When the toner sensor output voltage exceeds the toner empty detection level after toner replenishing is carried out,
the toner being replenished message appears disabling copying and forced toner feed starts. If the toner sensor
output voltage fails to fall to the toner feed stop level within 180 s of the start of forced toner feed, the toner request
message appears.
d: When toner is replenished, the toner sensor output voltage falls until it drops below the toner feed stop level and
replenishing stops. After 60 s aging (15 s while copying) the toner being replenished message disappears and
copying is enabled.
e: After replacing the toner cartridge and the waste toner tank, the toner feed motor (TFM) turns on to replenish toner.
f: When toner is replenished, the toner sensor output voltage falls until it drops to the toner feed stop level. The toner
being replenished message disappears and replenishing stops.