MB 716 Service manual

Service manual & parts

catalog

Colour Printer MB 716

MB CONFIDENTIAL

PREFACE

This manual describes the procedures of the maintenance of the MB 716 of printer. The document is produced for maintenance personnel use. For details on the procedures for handling the

MB 716 of printer, see its user documentation.

Note!

• The descriptions in this manual are subject to change without prior notice.

• In preparing the document, efforts have been made to ensure that the information in it is accurate. However, errors may be crept into the document. MB assumes no responsibility for any damage resulting from, or claimed to be the results of, those repairs, adjustments or modifications 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 MB.

41955801TH Rev.1 3 /

MB CONFIDENTIAL

1. CONFIGURATIONS ......................................................................................... 7

1.1 System Configuration....................................................................................................... 7

1.2 Printer Configuration ........................................................................................................8

1.3 Option Configuration ........................................................................................................ 9

1.4 Specifications................................................................................................................. 10

2. OPERATION DESCRIPTION ......................................................................... 12

2.1 Main Board (TIG PWB) .................................................................................................. 14

2.2 Engine Controller Board (K7N PWB) ............................................................................. 16

2.3 Power Units.................................................................................................................... 17

2.4 Mechanical Processes .................................................................................................. 18

2.4.1 Electrophotographic process............................................................................ 19

2.4.2 Paper running process ..................................................................................... 24

2.5 Sensor............................................................................................................................ 32

2.5.1 Paper related sensors ...................................................................................... 32

2.5.2 Other sensors................................................................................................... 33

2.6 Color Misalignment Correction....................................................................................... 34

2.7 Transfer Control Responds to Environmental Changes

(Room Temperatures and Relative Humidities)............................................................. 34

2.8 Paper Jam Detection ..................................................................................................... 35

2.9 Cover-Open ...................................................................................................................36

2.10 Toner Low Detection...................................................................................................... 37

2.11 Page Size Detection ...................................................................................................... 38

2.12 Operation at Power-on................................................................................................... 39

2.12.1 Self-diagnostic test........................................................................................... 39

2.13 Color Misalignment Detection ........................................................................................ 40

2.14 Version Read of Units Replaced Periodically ................................................................ 41

2.15 Life Count for Units Replaced Periodically..................................................................... 41

2.16 Toner Consumption Detection ...................................................................................... 41

3. PARTS REPLACEMENT................................................................................ 42

3.1 Precautions in Replacing Parts...................................................................................... 42

3.2 Parts layout .................................................................................................................... 44

3.3 Replacing Parts..............................................................................................................50

3.3.1 Top Cover......................................................................................................... 52

3.3.2 LED Head/ LED Assy Spring............................................................................ 53

3.3.3 Top Cover Unit ................................................................................................. 54

3.3.4 Control Panel Assy/ Control Panel Bezel/ LED Control PWB/

Toner Sensors Stacker Full Sensor/ Control Panel/

Control Panel Tape Harness/ Eject Rollers..................................................... 55

3.3.5 Top Cover Handle/ Top Cover Latch/ Top Cover Latch Spring........................ 56

3.3.6 Eject Guide Assy .............................................................................................. 57

3.3.7 Cassette Assy/ Front Cover Assy/ Front Cover Inner Baffle ........................... 58

3.3.8 Retard Pad Assy/ Retard Pad Assy Spring ...................................................... 59

3.3.9 Feed Roller and Nudger Roller......................................................................... 60

3.3.10 Rear Cover....................................................................................................... 61

3.3.11 Face-Up Tray.................................................................................................... 62

3.3.12 Left Side Cover................................................................................................. 63

3.3.13 Right Side Cover .............................................................................................. 64

3.3.14 Multipurpose Tray Assy/ Multipurpose Tray Cover Assy/ Links/

Multipurpose Tray Top Cover/ Multipurpose Tray Drive Gear.......................... 65

3.3.15 Drum Contact Assys......................................................................................... 66

3.3.16 Media Thickness Sensor Assy......................................................................... 67

3.3.17 Registration Roller Assy (A)/ Registration Drive Gear (A)................................ 68

3.3.18 Registration Roller Assy (B) ............................................................................. 69

3.3.19 Registration Clutch and Registration Motor Assy............................................. 70

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MB CONFIDENTIAL

3.3.20 Main Cooling Fan ............................................................................................. 71

3.3.21 Color Registration Sensor Assy........................................................................ 72

3.3.22 Duplex Guide Assy........................................................................................... 73

3.3.23 Electrical Chassis Cooling Fan......................................................................... 74

3.3.24 Printer Engine Controller PWB......................................................................... 75

3.3.25 Printer Unit Chassis.......................................................................................... 76

3.3.26 Entrance Cassette Sensor Actuator................................................................. 77

3.3.27 Entrance Sensor PWB...................................................................................... 78

3.3.28 Entrance MT Sensor Actuator / Entrance Belt Sensor Actuator /

Entrance Waste Chassis Sensor Actuator ...................................................... 79

3.3.29 Fuser Exit Roller............................................................................................... 80

3.3.30 Exit Sensor Assy .............................................................................................. 81

3.3.31 Fuser Latching Handle (L)................................................................................ 82

3.3.32 Belt Motor Assy ................................................................................................ 83

3.3.33 Fuser Latching Handle (R) ............................................................................... 84

3.3.34 Main Motor Assy............................................................................................... 85

3.3.35 Main Feeder Drive Motor.................................................................................. 86

3.3.36 Contact Assy/ Left Plate Assy .......................................................................... 87

3.3.37 Low Voltage Power Supply............................................................................... 88

3.3.38 High voltage power supply ............................................................................... 89

3.3.39 Main Feed Assy................................................................................................ 90

3.3.40 Cassette/ Left Guide Assy................................................................................ 91

3.3.41 Cassette/ Right Guide Assy.............................................................................. 92

3.3.42 Fuser Unit......................................................................................................... 93

3.3.43 Belt Unit............................................................................................................ 94

3.3.44 Duplex Unit....................................................................................................... 95

3.3.45 Guide Rails (L) and (R)..................................................................................... 96

3.3.46 Duplex Transport Assembly ............................................................................. 97

3.3.47 CU Assy............................................................................................................ 99

4. Adjustment .................................................................................................. 101

4.0 System Maintenance MENU........................................................................................ 101

4.0.1 ID Check Pattern Printing ( " TEST PRINT MENU " item )............................. 102

4.1 Maintenance Mode and Functions............................................................................... 102

4.1.1 Maintenance menu......................................................................................... 102

4.1.2 Engine maintenance mode............................................................................. 104

4.1.2.1 Operator panel ................................................................................ 104

4.1.2.2 Normal self-diagnostic mode (Level 1)............................................ 104

4.1.2.2.1 Entering self-diagnostic mode (Level 1).......................... 105

4.1.2.2.2 Exiting the self-diagnostic mode ..................................... 105

4.1.2.3 Switch scan test .............................................................................. 105

4.1.2.4 Motor clutch test.............................................................................. 109

4.1.2.5 Test print ......................................................................................... 111

4.1.2.6 Initializing NVM ............................................................................... 115

4.1.2.7 Displaying the consumables counter .............................................. 116

4.1.2.8 Displaying the consumables continuation counter .......................... 116

4.1.2.9 Panel display details ....................................................................... 117

4.1.3 Various print jobs with single printer unit attached with a controller............... 122

4.2 Adjustment After Replacing Parts ................................................................................ 123

4.2.1 Precautions in replacing the engine control board ......................................... 123

4.2.2 Precautions in replacing EEPROM................................................................. 123

4.2.3 Replacing EEPROM after replacing the TIG board........................................ 124

4.2.4 Destination Setting (Checking Metod: Printing Demo Page).......................... 124

4.2.5 Recovery Flash ROM data on TIG board....................................................... 125

4.3 Adjusting the Density ................................................................................................... 125

4.4 Paper Thickness Detection Sensitivity Adjustment and Media Thickness Detection

Value Check................................................................................................................. 126

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MB CONFIDENTIAL

5. regular maintenance ................................................................................... 128

5.1 Parts Replaced Regularly ............................................................................................ 128

5.2 Cleaning....................................................................................................................... 128

5.3 Cleaning the LED Lens Array ...................................................................................... 128

5.4 Cleaning the Pick-up Roller ......................................................................................... 128

6. Troubleshooting Procedures ..................................................................... 129

6.1 Precautions before troubleshooting ............................................................................. 129

6.2 Precautions before handling an abnormal image ........................................................ 129

6.3 Precautions upon handling an abnormal image........................................................... 129

6.4 Preparing for Troubleshooting ..................................................................................... 130

6.5 Troubleshooting Procedure.......................................................................................... 130

6.5.1 LCD message list ........................................................................................... 131

6.5.2 Preparing for troubleshooting ......................................................................... 137

6.5.3 Troubleshooting for abnormal images............................................................ 148

6.6 Fuse check................................................................................................................... 163

7. CONNECTION DIAGRAM............................................................................164

7.1 Resistance Checks ...................................................................................................... 164

7.2 Program/Font ROM Layouts ........................................................................................ 168

8. Parts List......................................................................................................174

APPENDIX A INTERFACE SPECIFICATIONS ................................................. 190

APPENDIX B 2ND/3RD TRAY MAINTENANCE .............................................. 194

APPENDIX C MB 716 ERROR MESSAGES .................................................... 199

1. MB 716 (Error messages) ........................................................................................... 199

2. MB 716 (Error messages : Related to Color, Media Detect) ....................................... 206

3. MB 716 (Warning messages : Related to usage, media) ............................................ 209

4. MB 716 (Warning messages : Job Account) ............................................................... 210

5. MB 716 (Other Warning) ............................................................................................. 211

41955801TH Rev.1 6 /

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/3rd Tray

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

< advanced Sensors,>

Media Thickness Detection

Density Detection

Color Misalignment Detectin

1. CONFIGURATIONS

1.1 System Configuration

Figure 1-1 shows the system configuration of the MB 716 of printer.

MB CONFIDENTIAL

Figure 1-1

41955801TH Rev.1 7 /

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.

MB CONFIDENTIAL

Figure 1-2

41955801TH Rev.1 8 /

1.3 Option Configuration

The followings are available as options on the C7000 Series of printers.

(1) 2nd Tray/ 3rd Tray

(2) Duplex Unit

MB CONFIDENTIAL

Note: Don’t use one for

C9200/C9400

(3) Expansion Memory 64/128/256/512 MB

(4) Internal Hard Disk

Note: Don’t use one for

C9200/C9400

Note: Don’t use one for

C9200/C9400

Note: Don’t use one for

C9200/C9400

(5) Ethernet Board

Note: Don’t use one for

C9200/C9400

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1.4 Specifications

(1) External Dimensions Height: 430mm Width: 430mm Length: 620mm

(2) Weight 42 kg

(3) Papers Type: Ordinary paper, Transparencies (Recommended: MLOHP01)

(4) Print Speed Color: 20 pages per minute (Transparency: 8 pages per minute)

(5) Resolution 600 × 1200 dots per inch

MB CONFIDENTIAL

Size: Postal card, Legal 13" or 14", Executive, A4, A5, B5, A6 (Only

the 1st tray and the front feeder support A6 and postal-card sizes.)

Weight: 1st tray55 kg to 151 kg (64 to 176g/m2)

Front feeder 55 kg to 172 kg (64 to 203g/ m2)

Monochrome: 24 pages per minute (Transparency: 12 pages per minute) Postal Card, Label, Thick Paper: 12 pages per minute

(6) Power Input 115 - 127 V , 220 - 240 V

(7) Power Consumption Peak: 1500W Normal Operation: 500W (5% duty)

Idle: 150W Power Saving Mode: 45W or less

(8) Frequency 50Hz or 60Hz ±2Hz

(9) Noise Operation: 56 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: Equivalent of 60,000 pages (3 pages/job)

41955801TH Rev.1 10 /

MB CONFIDENTIAL

(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

41955801TH Rev.1 11 /

2. OPERATION DESCRIPTION

N71 Board

Belt

Fuse

K Fuse

Y Fuse

M Fuse

C Fuse

JODEN

14P

Paper Tray 1 Paper Empty

Paper Tray 2 Near Empty

WHITE

BLUE

OPTION

BLUE

WHITE

KPOW

K1200

YPOW

Y1200

CPOW

C1200

OPTN

MPOW

M1200

YELLOW

FAN1 (Pr)

FAN2 (Pow)

Plate Senosr

Density

red

Gray

Blue

Z7L

Z7R

22P

14P

3P3P

10P

16P

R71 board

HOP(INSNS1)

PAPIN(INSNS2)

PSWR(WRSNS)

TNRFUL

Manual Bypass Feeder (MBF)

Hopping

Motor

FF/Regist

Motor

K IDU

Motor

Y IDU

Motor

M IDU

Motor

C IDU

Motor

Belt

Motor

Heat

Motor

MBF Stage

MBF Paper Empty

Duplex Unit

DUP

V71 Board

Motor

Clutch

INSENS

FSENS

RSENS

Main

14P

Front Cover

Open

Microswitch

Upper Cover

Open Microswitch

COVOPN

TR10P

JODEN

REG

FAN8

BEL THET

FEED

FSENS

RSNS

RCL

FAN1

FAN2

PCB-K7N

POWER

FAN

FAN(LEFT)

HVOLT

PSIZE

FCOVER

DUPLEX

CUIF

FAN4

black

yellow

red

FAN7

blue

FAN5

PARTTEMP

yellow

Exit sensor

cable40

Regist

clutch

SHUTTER

DCL

HOPFF

Main Motor Assy Belt Motor Assy

WHITE YELLOW

K LED HEAD

Control Panel

X7N board

Y LED HEAD

M LED HEAD

C LED HEAD

Toner Sensor (Y73-board)

Paper Size

Sensor

PXC-Board

AC Switch

CN1 CN1

CN5

CN2

High -voltage

power supply

Low-voltage

power supply

CN3

CN2

10P

26P

16P

Exit solenoid

Cord 7

TNRK

PANEL

STUCK

POWER

4P 4P

4P 4P 4P 4P

RED WHITE

BLACK YELLOW RED BLUE

KPOW2

TNRY

YPOW2

TNRM

MPOW2

TNRC

CPOW2

OPTN

16P

3P3P3P

14P

STUCKFULL

Sns.

FAN0

Up/Down

OHP Sen.

green

HUM

TEMP

yellow

Paper

thickness

RAM

TIG board

ROM

HDD

LAN

USB

CENTRO

FAN

shutter clutch

The MB 716 of printer, tandem color electrophotographic page printers, adopt technologies such as an LED array, OPC, dry single-component non-magnetic developing, roller transfer and heat-compression fusing. A black-writing printing method by shedding light on print areas is used.

Figure 2-1-1(600dpi),2-1-2(1200dpi) provides the block diagram of the printers.

MB CONFIDENTIAL

41955801TH Rev.1 12 /

Figure 2-1-1 600dpi

N71 Board

Belt

Fuse

K Fuse

Y Fuse

M Fuse

C Fuse

JODEN

14P

Paper Tray 1 Paper Empty

Paper Tray 2 Near Empty

WHITE

BLUE

OPTION

BLUE

WHITE

YELLOW

FAN1 (Pr)

FAN2 (Pow)

Plate Senosr

Density

red

Gray

Blue

Z7L

Z7R

22P

14P

3P3P

10P

16P

R71 board

HOP(INSNS1)

PAPIN(INSNS2)

PSWR(WRSNS)

TNRFUL

Manual Bypass Feeder (MBF)

Hopping

Motor

FF/Regist

Motor

K IDU

Motor

Y IDU

Motor

M IDU

Motor

C IDU

Motor

Belt

Motor

Heat

Motor

MBF Stage

MBF Paper Empty

Duplex Unit

DUP

V71 Board

Motor

Clutch

INSENS

FSENS

RSENS

Main

14P

Front Cover

Open

Microswitch

Upper Cover

Open Microswitch

COVOPN

TR10P

JODEN

REG

FAN8

BEL THET

FEED

FSENS

RSNS

RCL

FAN1

FAN2

PCB-K7N

POWER

FAN

FAN(LEFT)

HVOLT

PSIZE

FCOVER

DUPLEX

CUIF

FAN4

black

yellow

red

FAN7

blue

FAN5

PARTTEMP

yellow

Exit sensor

cable40

Regist

clutch

SHUTTER

DCL

HOPFF

Main Motor Assy Belt Motor Assy

WHITE YELLOW

K LED HEAD

Control Panel

X7N board

Y LED HEAD

M LED HEAD

C LED HEAD

Toner Sensor (Y7X-board)

Paper Size

Sensor

PXC-Board

AC Switch

CN1 CN1

CN5

CN2

High -voltage

power supply

Low-voltage

power supply

CN3

CN2

10P

26P

16P

Exit solenoid

Cord 7

TNRK

PANEL

STUCK

POWER

4P 4P

4P 4P 4P 4P

RED WHITE

BLACK YELLOW RED BLUE

KPOW2

TNRY

YPOW2

TNRM

MPOW2

TNRC

CPOW2

HEAD

32P

3P3P

14P

STUCKFULL

Sns.

FAN0

Up/Down

OHP Sen.

green

HUM

TEMP

yellow

Paper

thickness

RAM

TIG board

ROM

HDD

LAN

USB

CENTRO

FAN

shutter clutch

34P

32P

HEAD

CPOW C1200

M1200

MPOW

YPOW Y1200

K1200

KPOW

12P

14P

34P

HEAD32 HEAD34

MB CONFIDENTIAL

41955801TH Rev.1 13 /

Figure 2-1-2 1200dpi

2.1 Main Board (TIG PWB)

PU-CU

200

C2516

EEPROM

Video Data K, Y, M, C

Video I/F From PU

PU-CU I/F To C2 LSI

to PU PU-CU Command I/F

to PU Panel I/F

A [31:0]

SUB Bus A/D [31:0], Cont

[15:0]

SPD

[2]

[1]

[0]

SUB Bus

a Line Address. Cont

b Line Address. Cont

D [63:0]

[15:0][7:0]

D [63:0]

D [63:0] D [63:0]

[15:0]

Cont

Panel I/F From C2 LSI

3.3V

Reset IC

2.5V

1.8V

12V

3.3V

2.5V

14.31818MHz

Crystal

Resonator

M62733ML

(PU3V)

PST596

(PU12V)

PST596

(+5V)

internal

CPU CLK

setting Resister

PLL702-01

3.3V Regulator

PPC

750cx

Core:1.8V

I/O:2.5V

2.5V Regulator

CA1 LSI

MHM

2030-003

(uPD856

11N7)

Core:2.5V

I/O:3.3V

CPU I/O:2.5V

C2 LSI

MHM2031-002

DRCLK

3.3V 100MHz

RAMCLK

From 702

LVC

161284

PLL102-5

33MHz

33MHz 3.3V

USB

L60851

PCI

Slot

FPGA

for IDE

CENT

PCI

Reset

IDE

HDD

I/O 2.5V

74LVC04

to each LSI

MPUCLK

2.5V 100MHz

CA1CLK

2.5V 100MHz

48MHz

to USB

33MHz

Local

33MHz

48MHz

A,Cont

1.8V

Regulator

Flash

Mask 32bit

ROM DIMM

SDRAM DIMM

SDRAMCLK

3.3V 100MHz

PCI BUS [31:0]

Figure 2-2 provides the block diagram of the main control board (TIG PWB).

MB CONFIDENTIAL

41955801TH Rev.1 14 /

Figure 2-2

MB CONFIDENTIAL

(1) CPU

The CPU is PowerPC750CXe, a 64-bit bus RISC processor, which inputs an 100-MHz CLK (= BUS CLK), and operates at 450MHz that is 4.5 times the input.

(2) Cache

PPC750Cxe has its cache only inside of it. Speed: Same as CPU Core CLK speed Capacity: Primary Cache: 32 K bytes in D-cache capacity, 32 K bytes in I-cache capacity Secondary Cache: 256 K bytes

(3) ROM

ROM is to be inserted into the two 168 pin DIMM slots. The slot A is for program ROM and the slot B is for Japanese kanji fonts. The slot C is not assigned.

(4) RAM

RAM is to be inserted into the three 168 pin DIMM slots. The DIMMs must be fitted in descending labeled type No. order into the slots 1, 3, 2 and 4.

SDRAM DIMM Specifications:

Speed: PC133 or more Capacity: 64/128/256/512 MB Configuration: Without parity. Without ECC. SPD information is required.

(5) EEPROM

EEPROM, an 8-pin DIP package, is to be inserted into the IC socket. The EEPROM is of 16 Kbits for 3.3V power supply, and settings for controlling the controller block are stored in it.

(6) Flash ROM

A 4Mbyte flash ROM is surface-mounted on the TIG board. The flash ROM is composed of four 2048k-by-16bit chips, and fonts and macros can be stored in it.

(7) Memory Control LSI (CAI)

A 696-pin BGA package ASIC made by NEC. The chip mainly controls a CPU I/F, memory, video data compression and decompression, and a PU-video I/F.

(8) Interface Control LSI (C2)

A BGA package ASIC made by Toshiba, which controls a PU command I/F, operator panel I/F, IDE I/F, Centronics I/F, USB I/F, PCI I/F, EEPROM and a SPD (SDRAM DIMM) I/F.

(9) IDE HDD

An IDE connector is surface-mounted on the board to which an IDE HDD assembled using exclusive molds will be connected. The IDE HDD is used for storing font data, spooling edited video data and registering form data.

(10) PCI Bus Option

Two PCI I/F slots are provided for option board use. The bus, which uses an MB original connector, can accept an Ethernet board.

(11) Host Interface

Standard: Centronics two-way parallel I/F (IEEE-1284-compliant)

USB (USB1.1-compliant)

Additional Board: (connected to PCI BUS)

Ethernet Board

41955801TH Rev.1 15 /

2.2 Engine Controller Board (K7N PWB)

28MHz

MB CONFIDENTIAL

OPTION TRAY

PAPER THICKNESS SENSOR

COROR REGISTRATION SENSOR

HEAT ROLLER TEMP OHP

TEMPATURE HUMIDITY

HEAD TEMP DENSITY

COVER OPEN (UPPER, STACKER, RIGHT SIDE)

1ST TRAY SENSORS (PAPER END, PAPER NEAR END)

PAPER FEED SYSTEM SENSORS (PAPER FEED, PAPER REGISTRATION, EJECT)

MT SENSORS (STAGE POSITION, PAPER END)

DUPLEX

DISPOSAL TONER SENSOR

ANALOG

CPU

MSM66Q577

PAPER SIZE STACKER FULL

INT

CLK

RESET

FLASH

SRAM

MCON

LSI

EEPROM CONTROL

PANEL

MOTOR DRIVER

PULSE MOTOR *9

GEARED MOTOR

CLUTCH

PU FAN FUSER FAN

ID, BELT, FUSER CHECKS

HIGH VOLTAGE POWER SUPPLY SERIAL INTERFACE

32MHz

CLOCK GENERATOR

LED HEAD (K)

LED HEAD (Y)

LED HEAD (M)

LED HEAD (C)

SDRAM

DCON

LSI

Figure 2-3

The engine control block (PU) is controlled by the engine controller board (K71 PWB) which consists of a CPU (MSM66Q577), general LSI chip, flash ROM, EEPROM, pulse motor drivers and a video memory (see Figure 2-3).

(1) CPU

This, a 16-bit CPU with an AD converter (MSM66Q577), controls the entire system.

(2) General LSI

This LSI (UPD65454GD-241-LML, UPD65946GD-137-LML), which is contained in the printer engine control block, incorporates 4 megabits of video memory and has functions such as engine-controller interfacing, LED interfacing, motor control, sensor input, video memory control, main scan color misalignment correction, skew correction and high-voltage power supply control.

41955801TH Rev.1 16 /

MB CONFIDENTIAL

(3) MCON LSI

This LSI is used for inport of SENSORs and the cntrols of Pulse Motors,Cluches,FANs and High Voltage Power Suply.

(4) Flash ROM

The flash ROM (29F800-70) is of 8-Mbits, and PU programs are stored in it.

(5) EEPROM

The EEPROM (NM93C66N-NW) is of 4-Kbits, and mounted on the board with an IC socket. Correction values are stored in it.

(6) Pulse Motor Driver

The pulse motor driver (A2919SLBTR, A3955SLBTR,MTD2005) drives the eight pulse motors to revolve the ID and transport media.

(7) SRAM

This SRAM (628100LG-55L) is used as working memory of the CPU.

(8) SDRAM

This SRAM (56V16160T) is used as data memory of the DCON LSI.

2.3 Power Units

There are a low voltage power unit consists of an AC filter circuit, low voltage power circuit and heater driver circuit, and a high voltage power unit organizes a high voltage power circuit.

(1) Low Voltage Power Unit

This circuit generates the following voltages:

Output Voltage Use for

+5 V LED head +5 V Logic circuit power supply, PU CPU +34 V Motor, drive voltage and power supply voltage for high voltage power supply +12 V High voltage power supply, Media Thickness Sensor power supply

(2) High Voltage Power Unit

This circuit generates the following voltages of not less than +34V, which are required for electrophotographic process, according to control sequences from the controller board.

Output Voltage Use for Remark

CH -1000V to 1.4KV+/-50V Voltage to charging roller DB -50 to -300V/ +300V Voltage to developing roller SB -300V to -450V/ 0V Voltage to toner supplying roller TR C: 0KV to 7KV Voltage to transfer roller Variable

K,Y,M: 0KV to 6KV

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2.4 Mechanical Processes

Paper Eject Roller

Pape

ejection

(Face down)

Power Supply

Charging Roller

Cleaning Blade

Heat Roller

Paper

Eject

Roller

Fusing

Backup Roller

Control Signals

LED Head

Developing Roller

Power Supply

Toner Cartridge

Transfer Roller

Paper

registration

Registration

Roller 1

Paper loading

Hopping Roller

Power

Supply

Registration

Roller 2

Paper ejection Fusing Cleaning Transfer

Paper transport Paper advance

Transfer

Development

Paper Eject

Sensor

Paper Feed

Sensor 1

Paper Feed

Sensor 2

Paper Cassette

Paper

registration

(FF, 1ST, 2ND)

Write Sensor

YMC

Duplex printing

Paper path

selection

Paper path

selection

Paper traveling

OPC drum revolution

Charging

Exposure

Cleaning

Paper

ejection

(Face up)

Multipurpose Tray

Figure 2-4 shows the mechanical processes of the MB 716 of printer.

MB CONFIDENTIAL

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Figure 2-4

2.4.1 Electrophotographic process

(1) Electrophotographic process

The following is the outline of electrophotographic process:

1 Charging

DC voltage is applied to the charging roller and the surface of the OPC drum is negatively and evenly charged.

2 Exposure

The LED head, under image signals, emits light to the negatively charged surface of the OPC drum. The radiated portions of the drum surface attenuate in negative charge according to the intensity of the light and, based on the surface potentials, a latent electrostatic image is formed on the drum surface.

3 Development

Negatively charged toner contacts the OPC drum and by electrostatic force adheres to the latent electrostatic image to form a clear image on the drum surface.

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4 Transfer

Placed on the surface of the OPC drum, paper is positively, or opposite to the polarity of the toner, charged by the transfer roller on its back to transfer the toner image to the paper.

5 Cleaning

The cleaning blade removes residual toner from the OPC drum after the transfer.

6 Fusing

The toner image on the paper is fused into place through the application of heat and pressure to it.

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MB CONFIDENTIAL

(2) Charging

Negative DC voltage is applied to the charging roller contacting the surface of the OPC drum.

Power

unit

Charging roller

OPC drum

(3) Exposure

The negatively charged surface of the OPC drum is radiated with light from the LED head. The negative charge of the radiated portions of the drum surface attenuates in response to the intensity of the light and a latent electrostatic image responsive to the potentials of the surface is formed on the drum surface.

LED head

Power

unit

Charging roller

OPC drum

Paper

LED head

OPC drum

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MB CONFIDENTIAL

(4) Development

By the adhesion of toner to the latent electrostatic image on the drum surface, the image is changed to an image of its toner. The development is processed at the contact portion between the OPC drum and the developing roller.

1 The sponge roller causes toner to adhere to the developing roller. The toner becomes

negatively charged.

Developing blade

Charging roller

Sponge roller

OPC drum

Developing roller

2 The developing blade removes excess toner from the developing roller and a thin layer

of toner remains and forms on the developing roller.

3 The toner is drawn by the latent electrostatic image at the contact portion between the

OPC drum and the developing roller. The latent electrostatic image on the drum surface is made visible with the toner.

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MB CONFIDENTIAL

(5) Transfer

The transfer roller, which is made of conductive sponge, presses paper against the surface of the OPC drum and brings the paper into intimate contact with the drum surface. The paper is placed on the drum surface, and positively (opposite to the charge of the toner) charged by the transfer roller on its back. Applying positive high voltage from the power supply to the transfer roller moves the positive charge induced by the transfer roller to the paper surface at the contact portion between the transfer roller and the paper, the paper surface drawing the negatively charged toner from the drum surface.

OPC drum

Paper

Transport belt

Transfer roller

Power unit

(6) Fusing

When passing through between the heat roller and the backup roller, the toner image transferred to the paper is fused into place by the application of heat and pressure to it. The built-in upper and lower halogen lamps of 700 watts and 500 watts heat the Teflon coated heat roller. The fusing temperature is controlled by the sum of the temperature detected by the thermistor moving over the heat roller surface and the temperature detected by the thermistor moving over the backup roller surface. For safety, a thermostat is provided and, when the heat roller temperature rises by a fixed degree or more, becomes open to cut off voltage supply to the heater. The backup roller is being pressed against the heater by the pressure springs on both sides.

Thermostat

Thermistor

Heat roller

Paper

Thermostat

Backup roller

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Thermistor

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(7) Cleaning

Non-fused, residual toner on the OPC drum is scraped with the cleaning blade and collected in the waste toner area of the toner cartridge.

flexible Waste toner area

( This area will be expanded by waste toner. )

(8) Cleaning

Residual toner on the transfer belt is scraped with the cleaning blade and collected in the waste toner box of the transfer belt unit.

Cleaning blade

Waste toner box

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2.4.2 Paper running process

Figure 2-5 shows the traveling of paper in the MB 716 of printer.

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Registration roller Assy (B)

Hopping roller

Multipurpose tray

Registration roller Assy (A)

Cleaning blade

Transfer roller ×4

Feed roller

Unit × 4

Head × 4

High voltage power supply

Face-down stacker

MYK

Belt unit

Heat roller

Backup roller

Cassette 1

Cassette 2

Fuser

Eject roller

Low voltage

power supply

Figure 2-5 Paper Paths

Cassette 3

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(1) Paper Feed from Tray

1. The running of the feed motor in the arrow direction (a) drives the feed roller and the nudger roller. This operation feeds paper from the tray.

2. After the beginning of the paper turns the entrance cassette sensor on, the paper is advanced a fixed length. When the paper beginning reaches the registration roller Assy (A), the feed motor stops.

3. The running of the registration motor in the arrow direction (b), which synchronizes with the above paper advance operation, drives the registration roller Assy (B) and the electromagnetic clutch. The registration roller Assy (A) moves with the operation of the electromagnetic gear when the paper beginning touches the registration roller Assy (A), where the feed motor does not run. The feed roller idles via the built-in one-way clutch and the nudger roller idles because the planet gear is disengaged.

4. The registration motor transports the paper until the paper end passes through the entrance belt sensor.

Registration motor

Electromagnetic clutch

Registration roller Assy (A)

Entrance cassette sensor

Entrance belt sensor

Registration roller

Assy (B)

Feed motor

Feed roller (One-way clutch gear)

Paper gear

Nudger roller

Paper

Figure 2-6

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MB CONFIDENTIAL

(2) Paper Feed from Multipurpose Tray (MT)

1. The release lever usually pushes down the hopping plate to a position that turns microswitch on (Figure 2-7-a).

2. The running of the motor in the (a) direction drives the MT feed roller and turns the cam. The cam pushes the release lever and the hopping plate picks up paper sent out by the MT feed roller (Figure 2-7-b), where the registration roller Assy (B) does not move because its one-way clutch gear (1) idles.

3. After the paper beginning turns the entrance sensor on, the paper is forwarded a fixed length. The paper stops when its beginning reaches the registration roller Assy (B).

4. At the same time, the cam pushes down the hopping plate. The release lever that has been placed in its original position by the spring locks the hopping plate (Figure 2-7-c).

5. After the completion of the paper feed operation, the registration motor runs in the arrow direction (b) to drive the registration roller Assy (B), where the one-way clutch gear (2) does not allow the MT feed roller to move.

Paper

Registration motor

One-way clutch gear (2)

MT feed roller

Entrance sensor

Entrance belt sensor

Registration roller Assy (B)

One-way clutch gear (1)

Figure 2-7

Spring

Release lever

Hopper plate

Feed roller

Microswitch

Figure 2-7-a Figure2-7-b Figure 2-7-c

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MB CONFIDENTIAL

(3) Transport Belt

1. The running of the transport belt motor in the arrow direction (a) drives the transport belt. The belt unit sits with one transport roller immediately below each color’s drum, and the transport belt between them. By the application of a fixed voltage, the transport belt and the transport roller feed paper on the transport belt into the fuser unit, transferring a toner image on each color’s drum.

Drum

Transport belt

KYMC

Transport (transfer) roller

Figure 2-8

Transport (transfer) belt motor

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MB CONFIDENTIAL

(4) Driving and Up-and-Down Movements of I/D Unit

1. The I/D unit driving and up-and-down movements are effected by a single-pulse motor. The running of the main motor in the arrow direction (a) turns the lever 1 to the left. Then, the lever 2 that was lifted by the lever 1 lowers to move down the I/D unit. After the up/ down sensor is turned off (Figure 2-9-d), specified downward pulsing places the I/D unit in its lowest position, or equivalently, printing position (Figures 2-9-a and 2-9-c). The drum gear engages with the driving gear and starts revolving to transfer an image on the drum to running paper, where the one-way gear idles upon placement of the lever in its lowest position.

2. With the running of the main motor in the arrow direction (b), the lever 1 pushes up the I/D unit via the lever 2. After the up/down sensor is activated (Figure 2-9-d), the lever 1 lifts the I/D unit to a specified level and stops to keep space to an extent between the drum and the transport belt (Figures 2-9-c and 2-9-e). The drum gear is not engaged with the driving gear and does not revolve.

3. When the two pins of the up/down sensor are pushed up by the I/D unit, and touches and electrically connected to the plate above the pins, the sensor recognizes the on state. When the two pins are pushed down by the I/D unit, and separated and insulated from the plate, the sensor recognizes the off state. The installation of the I/D unit can also be verified by recognizing the off state of the up/ down sensor.

Lever 2

Driving gear

I/D unit

Drum

One-way gear

Lever 1

Figure 2-9-a Figure 2-9-b

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Plate

Pin Spring

Board

MB CONFIDENTIAL

Up/down sensor

Figure 2-9-c

Figure 2-9-d

Figure 2-9-e

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MB CONFIDENTIAL

(5) Fuser Unit and Paper Ejection

1. A single-pulse motor drives the fuser unit and the eject rollers. In response to the running of the heat motor in the arrow direction (a), the heat roller turns. This roller fuses a toner image to paper by heat and pressure.

2. At the same time, the four eject rollers move to eject the paper.

3. The ejection path is switched back and forth between the route to the face-up stacker and the route to the face-down stacker as follows. When the face-up stacker opens, the paper separator inclines in the direction that guides the paper to the face-up stacker. When the face-up stacker closes, the paper separator inclines in the direction that sends the paper to the face-up stacker.

Eject rollers

Fuser unit

Heater motor

Heat rollers

Figure 2-10

Paper separator

Face-up stacker

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MB CONFIDENTIAL

(6) Duplex Unit

1. When the duplex unit receives an instruction from the printer to print on both sides of a sheet of paper, the solenoid opens the separator after the completion of one side printing of a sheet of paper sent from the tray. The path is switched to that to the duplex unit. At this time, as the roller (1) turns in the direction of the arrow “a,” the paper is retracted on the rear of the cassette.

2. When fixed time has elapsed after the paper beginning passes through the duplex-in sensor, the rollers reverse and the roller (1) turns in the direction of the arrow “b” to feed the paper into the duplex unit. After that, the paper passes through the rollers (2), (3) and (4), and ejected with the other side printed, and fed again into the printer.

Figure 2-11

Separator Solenoid Duplex-in sensor

Motor

Roller(2)Roller(3)Roller(4)

Roller(1)

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+ 181 hidden pages

MB 716 Service manual

Specifications and Main Features

Frequently Asked Questions

User Manual

PREFACE

CONTENTS

1. CONFIGURATIONS