Oki C7400 User manual

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Oki Data CONFIDENTIAL
C7400/C7200
Color LED Page Printer
MAINTENANCE MANUAL
ODA/OEL/INT
2002-12-12 Rev.9

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Oki Data CONFIDENTIAL
1 2000-05-29 ISSUE E4 Yamazaki
2 2000-05-31 E4 Murakami
3 2000-12-04 NIP9 Yamazaki
4 2000-12-15 NIP9 Yamazaki
5 2001-05-15 CN11 Kasuya
6 2001-10-12 NP33 YAMAZAKI
7 2002-05-28 NP33 YAMAZAKI
8 2002-08-09
9 2002-12-12 NP34 Ueda
Rev.No. Date No.
Corrected items
Page Description of change Person in
charge
Document Revision History

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Oki Data CONFIDENTIAL
PREFACE
This manual describes the procedures of the maintenance of the C7400/C7200 of printers.
Thedocumentisproducedformaintenancepersonneluse. Fordetailsontheproceduresforhandlingthe
C7400/C7200 of printers, see its user documentation.
Note! • The descriptions in this manual are subject to change without prior notice.
• Inpreparingthedocument,effortshavebeenmadetoensurethattheinformationinitisaccurate.
However, errors may be crept into the document. Oki Data assumes no responsibility for any
damage resulting from, or claimed to be the results of, those repairs, adjustments or modifica-
tions to the printers which are made by users using the manual.
• The parts used for the printers are sensitive and, if handled improperly, may be damaged. It is
strongly recommended that the products are maintained by maintenance men registered with
Oki Data.

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CONTENTS
1. CONFIGURATIONS ......................................................................................... 7
1.1 System Configuration....................................................................................................... 7
1.2 Printer Configuration ........................................................................................................8
1.3 Option Configuration ........................................................................................................ 9
1.4 Specifications................................................................................................................. 10
2. PARTS REPLACEMENT................................................................................ 12
2.1 Precautions in Replacing Parts...................................................................................... 12
2.2 Parts layout .................................................................................................................... 14
2.3 Replacing Parts..............................................................................................................20
2.3.1 Top Cover......................................................................................................... 22
2.3.2 LED Assy/ LED Assy Spring............................................................................. 23
2.3.3 Top Cover Unit ................................................................................................. 24
2.3.4 Control Panel Assy/ Control Panel Bezel/ LED Control PWB/ Toner Sensors/
Stacker Full Sensor/ Control Panel/ Control Panel Tape Harness/
Eject Rollers ..................................................................................................... 25
2.3.5 Top Cover Handle/ Top Cover Latch/ Top Cover Latch Spring........................ 26
2.3.6 Eject Guide Assy .............................................................................................. 27
2.3.7 Cassette Assy/ Front Cover Assy/ Front Cover Inner Baffle ........................... 28
2.3.8 Retard Pad Assy/ Retard Pad Assy Spring ...................................................... 29
2.3.9 Feed Roller and Nudger Roller......................................................................... 30
2.3.10 Rear Cover ....................................................................................................... 31
2.3.11 Face-Up Tray.................................................................................................... 32
2.3.12 Left Side Cover................................................................................................. 33
2.3.13 Right Side Cover .............................................................................................. 34
2.3.14 Multipurpose Tray Assy/ Multipurpose Tray Cover Assy/ Links/
Multipurpose Tray Top Cover/ Multipurpose Tray Drive Gear.......................... 35
2.3.15 Drum Contact Assys......................................................................................... 36
2.3.16 Registration Roller Assy (A)/ Registration Drive Gear (A) ................................ 37
2.3.17 Registration Roller Assy (B) ............................................................................. 38
2.3.18 Registration Clutch and Registration Motor Assy............................................. 39
2.3.19 Main Cooling Fan ............................................................................................. 40
2.3.20 Color Registration Sensor Assy........................................................................ 41
2.3.21 Duplex Guide Assy........................................................................................... 42
2.3.22 Electrical Chassis Cooling Fan......................................................................... 43
2.3.23 Printer Engine Controller PWB ......................................................................... 44
2.3.24 Printer Unit Chassis.......................................................................................... 45
2.3.25 Entrance Cassette Sensor Actuator ................................................................. 46
2.3.26 Entrance Sensor PWB...................................................................................... 47
2.3.27 Entrance MT Sensor Actuator and Entrance Belt Sensor Actuator.................. 48
2.3.28 Fuser Exit Roller ............................................................................................... 49
2.3.29 Exit Sensor Assy .............................................................................................. 50
2.3.30 Fuser Latching Handle (L) ................................................................................ 51
2.3.31 Belt Motor Assy ................................................................................................ 52
2.3.32 Fuser Latching Handle (R) ............................................................................... 53
2.3.33 Main Motor Assy............................................................................................... 54

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2.3.34 Main Feeder Drive Motor.................................................................................. 55
2.3.35 Contact Assy/ Left Plate Assy .......................................................................... 56
2.3.36 Low Voltage Power Supply............................................................................... 57
2.3.37 High voltage power supply ............................................................................... 58
2.3.38 Main Feed Assy................................................................................................ 59
2.3.39 Cassette/ Left Guide Assy ................................................................................ 60
2.3.40 Cassette/ Right Guide Assy.............................................................................. 61
2.3.41 Fuser Unit ......................................................................................................... 62
2.3.42 Belt Unit ............................................................................................................ 63
2.3.43 Duplex Unit ....................................................................................................... 64
2.3.44 Guide Rails (L) and (R)..................................................................................... 65
2.3.45 Duplex Transport Assembly ............................................................................. 66
2.3.46 CU Assy............................................................................................................ 68
3. ADJUSTMENTS .............................................................................................70
3.1 Maintenance Modes and Their Functions...................................................................... 70
3.1.1 Maintenance menu........................................................................................... 70
3.1.2 Engine maintenance mode............................................................................... 71
3.1.2.1 Operator panel .................................................................................. 71
3.1.2.2 General self-diagnosis mode (level 1)............................................... 71
3.1.2.2.1 Entering self-diagnosis mode (level 1) .............................. 71
3.1.2.2.2 Exiting self-diagnosis mode .............................................. 71
3.1.2.3 Switch scan test ................................................................................ 72
3.1.2.4 Motor and clutch test......................................................................... 75
3.1.2.5 Test printing ...................................................................................... 77
3.1.2.6 NVM initialization.............................................................................. 81
3.1.2.7 Consumable counter display............................................................. 82
3.1.2.8 Consumable counter display - continuous ........................................ 82
3.1.2.9 Error Messages and their Details...................................................... 83
3.1.3 SWA board adjustments................................................................................... 87
3.1.3.1 Short plug settings ............................................................................ 88
3.1.3.2 Printings singly using controller-equipped printer ............................. 88
3.2 Adjustments after Parts Replacement ........................................................................... 89
3.2.1 Precautions in replacing engine controller board ............................................. 89
3.2.2 Precautions in replacing EEPROM................................................................... 89
3.2.3 EEPROM replacement after SWA board replacement..................................... 90
3.3 Color Balance Adjustment ............................................................................................. 91
4. PERIODIC MAINTENANCE ........................................................................... 93
4.1 Parts Replaced Periodically ........................................................................................... 93
4.2 Cleaning......................................................................................................................... 93
4.3 Cleaning LED Lens Array .............................................................................................. 93
4.4 Cleaning Pickup Roller................................................................................................... 93
5. TROUBLESHOOTING PROCEDURES ......................................................... 94
5.1 Before Troubleshooting.................................................................................................. 94
5.2 Checking before Troubleshooting Image Problems....................................................... 94
5.3 Precautions in Troubleshooting Image Problems .......................................................... 94

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5.4 Preparation for Troubleshooting .................................................................................... 94
5.5 Troubleshooting ............................................................................................................. 94
5.5.1 LCD messages list............................................................................................ 95
5.5.2 Preparation for troubleshooting ...................................................................... 100
5.5.3 Troubleshooting image problems ................................................................... 111
6. CONNECTION DIAGRAM............................................................................ 125
6.1 Resistance Checks ...................................................................................................... 125
6.2 Program/Font ROM Layouts ........................................................................................ 129
7. Parts List ...................................................................................................... 133
APPENDIX A CENTRONICS PARALLEL INTERFACE................................... 149
APPENDIX B 2ND/3RD TRAY MAINTENANCE .............................................. 153
1. Parts Replacement ...................................................................................................... 153
1.1 Cover Idle Roller Assy .................................................................................... 153
1.2 PCB ................................................................................................................ 154
1.3 Feeder Drive Assy .......................................................................................... 155
2. C7400/C7200 2nd/3rd Tray PARTS LIST.................................................................... 156

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MMMMMMMM
LED Head
Centronics I/F
USB I/F
2 × Option Slots
Junction Board
Pulse Motor
Engine Control
Low Voltage
Power Unit
Fuser
Unit
High Voltage
Power Unit 2nd/3rdTray
Duplex
Unit
Belt
Unit
<Sensors, Switches and Thermistors>
Paper size sensor (4 bits)
Paper empty sensor
Paper near empty sensor
MT paper empty sensor
FF home switch
Loading sensor 1
Loading sensor 2
C-ID
Unit
M-ID
Unit
Y-ID
Unit K-ID
Unit
C ID M ID Y ID K IDBelt Heat MT/
Registration Hopping
Operator Panel
3 × ROM
DIMMs
4 × RAM
DIMM
IDE
I/F(HDD)
DC Fan
Note
Note Option Slot:
LAN Card made by JCI
1. CONFIGURATIONS
1.1 System Configuration
Figure 1-1 shows the system configuration of the C7400/C7200 of printers.
Figure 1-1

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1.2 Printer Configuration
The inside of the printers is composed of the followings:
• Electrophotographic Processor
• Paper Paths
• Controller Block (CU and PU)
• Operator Panel
• Power Units (High Voltage Unit and Low Voltage Unit)
Figure 1-2 shows the printer configuration.
Figure 1-2
A
B
A
B
B
A
A
B

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Oki Data CONFIDENTIAL
1.3 Option Configuration
The followings are available as options on the C7400/C7200 of printers.
(1) 2nd Tray/ 3rd Tray
(2) Duplex Unit
(3) Expansion Memory 64/128/256 MB
(4) Internal Hard Disk
(5) Ethernet Board

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1.4 Specifications
(1) External Dimensions Height: 430mm Width: 430mm Length: 620mm
(2) Weight 42 kg
(3) Papers Type: Ordinarypaper,Transparencies(Recommended:MLOHP01)
Size: Postalcard,Legal13"or14",Executive,A4,A5,B5,A6(Only
the 1st tray and the front feeder support A6 and postal-card
sizes.)
Weight: 1st tray55 kg to 90 kg (64 to 105g/m2)
Front feeder 55 kg to 140 kg (64 to 163g/ m2)
(4) Print Speed Color: 12 pages per minute (Transparency: 5 pages per minute)
Monochrome: 20pagesperminute(Transparency: 12pagesperminute)
Postal Card, Label, Thick Paper: 8 pages per minute
(5) Resolution 600 ×600 dots per inch
(6) Power Input 100VAC ±10%
(7) Power Consumption Peak: 1300W Normal Operation: 400W (5% duty)
Idle: 110W Power Saving Mode: 45W or less
(8) Frequency 50Hz or 60Hz ±2%
(9) Noise Operation: 54 dB (Without second tray)
Standby: 45 dB
Power Saving: 43 dB
(10) Consumable Life Toner Cartridge: 5,000 pages (5% duty) (each of Y, M, C and K)
Large-Capacity Toner Cartridge: 10,000 pages (5% duty)
(each of Y, M, C and K)
Image Drum: 30,000 pages (5% duty, Continuous printing)
(each of Y, M, C and K)
(11) Parts Replaced Periodically Fuser Unit Assy: Every 60,000 pages
Belt Cassette Assy: Equivalentof60,000pages(3pages/job)

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(12) Temperatures and Relative Humidities
Temperature
Temperature Condition
Temperature (˚F) Temperature (˚C) Remark
Operation 50 to 89.6 10 to 32 17 to 27˚C
(Temperatures to assure full
color print quality)
Non-Operation 32 to 109.4 0 to 43 Power-off
Storage (Max. One Year) -14 to 109.4 -10 to 43 With drum and toner
Transport (Max. One Month) -20 to 122 -29 to 50 With drum and without toner
Transport (Max. One Month) -20 to 122 -29 to 50 With drum and toner
Humidity
Humidity Condition
Relative Humidity Max. Wet-Bulb Remark
(%) Temperature(˚C)
Operation 20 to 80 25 50 to 70% (Humidities to assure full
color print quality)
Non-Operation 10 to 90 26.8 Power-off
Storage 10 to 90 35
Transport 10 to 90 40
(13) Printer Life 600,000 pages (on a A4-size basis) or five years

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Oki Data CONFIDENTIAL
(2) Do not disassemble the printer so long as it operates properly.
(3) Minimize the disassembly. Do not detach parts other than those shown in the replacing procedure.
(4) For maintenance, use designated tools.
(5) Followtheorderinstructedtodisassembletheprinter. Incorrectordermaydamagetheparts.
(6) Small parts such as screws and collars tend to get lost, so temporarily place and fix them in
their original positions.
(7) WhenhandlingICsandcircuitboardssuchasmicroprocessors,ROMsandRAMs,donotuse
gloves that likely to have static.
(8) Do not place the printed circuit boards directly on the printer or the floor.
2. PARTS REPLACEMENT
Thissectiondescribestheprocedureforreplacingtheparts,assembliesandunitsinthefield. The
replacing procedure is given for detachment. To attach, use the reverse procedure.
2.1 Precautions in Replacing Parts
(1) Before replacing the parts, be sure to remove the AC cable and the interface cable.
(a) To remove the AC cable, always use the following procedure.
i) Flip the power switch of the printer off (to “O”).
ii) Pull the AC inlet plug of the AC cable out of the AC receptable.
iii) Remove the AC cable and the interface cable from the printer.
(b) To connect the printer again, always use the following procedure.
i) Connect the AC cable and the interface cable to the printer.
ii) Insert the AC inlet plug into the AC receptacle.
iii) Flip the power switch of the printer on (to “I”).
Disconnect
Connect

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Oki Data CONFIDENTIAL
[Maintenance Tools]
Table 2-1 lists tools necessary to replace the printed circuit boards and the units.
Table 2-1 Maintenance Tools
No.
No. 1-100 Philips
screwdriver
Q' ty Use for RemarkMaintenance Tools
1
2
3
4
5
6
8
No. 2-200 Philips
magnetic screwdriver
No. 3-100 screwdriver
No. 5-200 screwdriver
Digital multimeter
Pliers
Handy cleaner
LED Head cleaner
P/N 4PB4083-2248P001
1
1
1
1
1
1
1
Screws of 2 to 2.5mm
Screws of 3 to 5mm
LED head cleaning
9High-voltage probe 1
7 1

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2.2 Parts layout
Figure 2-1
A
B
A
B
B
A
A
B

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[Top Cover Assy]
Figure 2-2

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[Printer Unit-1/2]
Figure 2-3
A
A

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[Printer Unit-2/2]
Figure 2-4
45

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[Cassette Guide Assy (L),(R)]
Figure 2-5
A
B
B
ACC’
CC’

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[Duplex Unit]
A
B
DC
A
B
C
D
E
E
F
G
G
F
Figure 2-6

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Oki Data CONFIDENTIAL
2.3 Replacing Parts
Thissectiondescribeshowtoreplacethepartsandassembliesshowninthefollowingdisassembling
system diagram.
C7400/
C7200 41256204 Print Engine Controller PWB (2.3.23)
X 4
LED Assy (2.3.2)
40737401
LowVoltage Power Supply (2.3.36)
40737601
High Voltage Power Supply (2.3.37)
Cassette Guide
Printer Unit
4112801PP
Insurator
PB4076-5290P001
Main Cooling Fan Assy (2.3.19)
2381018P0001
HV Tape Harness
40841101
Printer Chassis (2.3.16)
40844301
Regist Roller Assy (A) (2.3.16)
40844303
Regist Roller Assy (B) (2.3.17)
40845801
Registration Motor Assy (2.3.18)
41187101
Registration Clutch (2.3.18)
40859201
Duplex Guide Assy (2.3.21)
40847301
Main Motor Assy (2.3.33)
40846001
Main Feeder Motor (2.3.34)
40848801
Transport (Transfer) Belt Motor Assy (2.3.35)
40850201
Contact Assy (2.3.35)
41303601
Left Plate Assy (2.3.35)
40866301PA
Multipurpose Tray Cover Assy (2.3.14)
40864301
Rear Cover (2.3.10)
40864401
Left Side Cover (2.3.12)
40864501
Right Side Cover (2.3.13)
40864601
Front Cover Assy (2.3.7)
41042501
Front Cover Inner Baffle (2.3.7)
1PA4128-1074G001
Face Up Tray (2.3.11)
40864901PA
Frame Assy - Release
40841401
Fuser Latching Handle (R) (2.3.32)
40841501
Fuser Latching Handle Spring (2.3.32)
40848501
Main Feeder Drive Gear A (2.3.34)
40846601
Main Feeder Drive Gear B (2.3.34)
40839001
Left Cassette Guide Assy (2.3.39)
40839401
Right Cassette Guide Assy (2.3.40)
40839801
Main Feed Assy (2.3.38)
4PP4122-1217P001
Plastic Slide (2.3.39)
40349102
Cassette Guide Pivot (R) (2.3.39)
40349701
Plastic Roller (2.3.39)
40928101
Cassette Spring (2.3.39)
4PP4076-5359P001
Cassette Lock (2.3.39)
4PP4043-4526P001
Cassette Lock Spring (2.3.39)
4PB4016-1960P002
× 2
Foot (2.3.39)
40841301
Fuser Latching Handle (L) (2.3.30)
40841501
Fuser Latching Handle Spring (2.3.30)
40841601
Entrance Sensor Actuator #1 (2.3.25)
40841701
Entrance Sensor Actuator #2 (2.3.27)
40841801
Entrance Senspr Actuator #3 (2.3.27)
40842201
Waste Toner Sensor Actuator (2.3.27)
41253601
Duplex Gate solenoid Assy (2.3.28)
41253701
Registration Shutter Solenoid Assy
41275201
Registration Shutter
41275301
Registration Shutter Spring
41067201
Fuser Drive Gear-C (2.3.28)
40323901
Fuser Exit Roller (2.3.28)
40316301
Fuser Drive Gear-B (2.3.28)
4PP4076-3949P001
Fuser Exit Roller Bushing (L) (2.3.28)
4PP4043-4489P001
Fuser Exit Roller Bushing (R) (2.3.28)
41189701
× 4
Drum Contact Assy (2.3.15)
41258301
Entrance Sensor PWB (2.3.26)
41312801
Left Top Cover Spring Assy (2.3.24)
41312901
Right Top Cover Spring Assy (2.3.24)
40346801
Color Registration Sensor Assy (2.3.20)
41073601
Exit Sensor Assy (2.3.29)
40371301
Feed Roller (2.3.9)
40325401
Main Feeder Drive Gear (2.3.38)
40313201
Nudger Roller (2.3.9)
4PP4122-1217P001
Plastic Slide (2.3.40)
40349101
Cassette Guide Pivot (L) (2.3.40)
40349701
Plastic Roller (2.3.40)
40928101
Cassette Spring (2.3.40)
4PP4076-5359P001
Cassette Lock (2.3.40)
4PP4043-4526P001
Cassette Lock Spring (2.3.40)
4PB4016-1960P002
× 2
Foot (2.3.40)
40368304
Paper Size Sensing PWB PXC (2.3.40)
4PP4076-5360P001
Paper Size Actuator (2.3.40)
41143701
Duplex Assy Ground contact (2.3.40)
41309301
2nd Tray Connector (2.3.40)
41285701PA
Plate Assy-SW(Front) (2.3.40) 41275801PA
Microswitch-Assy (2.3.40)
41275901PA
Microswitch-Assy (2.3.40)
A