Apple Laserwriter Ii Service Manual

K

Service Source

LaserWriter II

LaserWriter II SC, LaserWriter II NT,

LaserWriter II NTX, LaserWriter IIf, LaserWriter IIg

K

Service Source

Basics

LaserWriter II

Basics Product Information - 1

Product Information

The printers covered in this manual are

• LaserWriter II SC

• LaserWriter II NT

• LaserWriter II NTX

• LaserWriter IIf

• LaserWriter IIg

Compatibility:

Except for I/O boards components, all parts are compatible
among the five models. Refer to Illustrated Parts and Take
Apart chapters for more information. Refer to “Print
Engine Check” in Flowcharts for Troubleshooting
information.

Basics Startup Test Page - 2

Startup Test Page

LaserWriter II printers
generate a startup test page
approximately 2 – 3
minutes after you switch on
the printer.

Except for the IISC, the
startup test page also shows
unit-specific configuration
information. The following
pages describe each element
of the startup test page.

Basics Startup Test Page - 3

I/O Board

Type

II NT/NTX Startup Test Page

Printer
Name

Number of pages the I/O board has produced

Configuration
PostScript, Diablo 630, or Hewlett Packard
LaserJet Plus™ emulation (NTX only)

Communication Protocol
RS-232 serial or AppleTalk

Fonts in ROM

Installed RAM

Size of hard drive, if connected, and
number of fonts it contains (NTX only)

Version of ROM installed

Ê

Basics Startup Test Page - 4

IIf Startup Test Page

Printer
Name

Communication parameters and printer control

I/O Board

Type

Number of pages the I/O board has produced

language selected for an individual printer port

Version of ROM installed

Fonts in ROM

Installed RAM

FinePrint feature enabled

Basics Startup Test Page - 5

IIg Startup Test Page

Printer
Name

Communication parameters and printer control

I/O Board

Type

Number of pages the I/O board has produced

language selected for an individual printer port

Version of ROM installed

Fonts in ROM

Installed RAM

FinePrint feature enabled

Basics Startup Test Page - 6

IISC Startup Test Page

The LaserWriter IISC test
page consists only of
vertical lines. The printer
will generate a test page
only if its SCSI address has
been set to 7 prior to
powering up.

Note:

Be sure to set the SCSI
address back before you
resume printing.

Basics Service Test Page - 7

Service Test Page

The service test page is
generated by the DC
controller board and serves
to confirm print engine
operation. To generate this
test page, remove the bottom
panel cap located at the rear
of the printer. Insert a
screwdriver or similar
dowel-shaped tool through
the quarter inch diameter
opening and press the
service test page button.

Basics Preventive Maintenance - 8

Preventive Maintenance

Before performing any preventive maintenance, be sure to
do the following:

1 Check the page count on the startup test. If the I/O board

has been replaced or upgraded, check the repair log label
affixed to the bottom of the printer or consult with the
customer to determine page count.

2 Power off and unplug the printer.

3 Allow the fuser assembly rollers to cool.

4 Prepare your work area for electrostatic discharge

prevention.

5 Spread a drop cloth under the work area to protect the

floor from grease and spilled toner.

Caution:

Never use an ammonia-based cleaner on the

Basics Preventive Maintenance - 9

LaserWriter II. These cleaners can discolor the plastic.

Caution:

the printer has been off at least 5 minutes to allow the fuser
assembly to cool.

The service provider should clean the following items every
12 months or during each service call.

Service Point Tool/Solvent

Primary corona wire Cleaning brush supplied with

Transfer corona wire Cotton swab and isopropyl

Transfer guide Cloth dampened with water

Fuser rollers Fuser cleaning pad

Before servicing the fuser rollers, make sure that

printer

alcohol

Basics Preventive Maintenance - 10

Service Point Tool/Solvent

Exterior case Cloth dampened with water

Separation claws Cloth dampened with alcohol

Paper guide Cloth dampened with alcohol

Lower delivery guide Cloth dampened with alcohol

Feeder guide Cloth dampened with water

Registration rollers Cloth dampened with water

Basics Parts Replacement Schedule - 11

Parts Replacement Schedule

Perform the following tasks every 50,000 prints:

• Replace the ozone filter

• Check upper and lower fan operation.

Replace the following parts every 100,000 prints:

• Fuser assembly

• Transfer guide assembly

• Preconditioning exposure assembly

• Paper feed roller assembly

• Transfer corona assembly

The LaserWriter II refurbishment kit (P/N 652-0597)
contains one each of the parts listed above.

K

Service Source

Specifications

LaserWriter II

Specifications General - 2

General

Engine

Printing Method

Optical System

Resolution

Imaging Languages Supported

Canon SX engine

Electrophotography using single-component, dry toner

Semiconductor laser and a rotating six-faced prism scanning

mirror

300 dpi

SC: QuickDraw
NT: PostScript and a subset of the Diablo 630 printer
NTX/NTX-J: PostScript, a subset of the Diablo 630 printer, and a

subset of the Hewlett-Packard LaserJet Plus

Specifications General - 3

f/g: PostScript Level 1 and 2 and HP LaserJet IIP (HP PCL4)

Note:

NTX-J does not support emulation mode.

Specifications Intro Dates - 4

Intro Dates

SC, NT, and NTX

IIf and IIg

July 1990

October 1991

Specifications Logic Board - 5

Logic Board

CPU

DRAM

SC: Motorola 68000 microprocessor (7.45 MHz)
NT: Motorola 68000 microprocessor (11.16 MHz)
NTX/NTX-J: Motorola 68020 microprocessor (16.67 MHz)
f: Motorola 68030 microprocessor (20.0 MHz)
g: Motorola 68030 microprocessor (25.0 MHz)

SC: 1 MB
NT: 2 MB
NTX: 2 MB, expandable to 12 MB
NTX-J: 4 MB, expandable to 12 MB
f: 2 MB/5MB, expandable to 32 MB
g: 5 MB/8MB, expandable to 32 MB
Ê

Specifications Logic Board - 6

ROM

I/O

SC: 16 KB
NT: 1 MB
NTX/NTX-J: 1 MB, expandable to 8 MB on expansion board
f: 2 MB standard; ROM expansion slot provided
g: 2 MB standard; ROM expansion slot provided

SC: SCSI, Apple Desktop Bus (ADB)
NT: RS-232/422, LocalTalk, ADB
NTX/NTX-J: RS-232/422, LocalTalk, SCSI, ADB
f: RS-232/422; LocalTalk; SCSI
g: RS-232/422; LocalTalk; SCSI; Ethernet

Specifications Performance - 7

Performance

Printing Speed

Duty Cycle

Minimum Life Expectancy

Major Service Interval

8 pages per minute (all paper sizes except legal)
7 pages per minute (legal size)

Note:

Actual performance depends on the application.

No limit in pages per month

300,000 pages

100,000 copies

Ê

Specifications Performance - 8

Printable Area

All measurements are in inches:

SC
US Letter : 8.00 by 10.60
Legal: 6.72 by 12.50
A4: 8.00 by 11.27
B5: 6.67 by 9.43
#10 Envelopes: 3.84 by 9.10

NT, NTX, and NTX-J
US Letter : 8.00 by 10.78
Legal: 8.00 by 13.78
A4: 7.79 by 11.08
B5: 6.45 by 9.76
#10 Envelopes: 3.84 by 9.10

Specifications Performance - 9

IIf Ê
US Letter : 8.11 by 10.79
Legal: 8.00 by 10.78 (Maximum printable area with 2 MB of

RAM. Prints up to 8.00 x 13.78 with 5 MB of RAM. Prints up

to 8.00 x 13.78 using PhotoGrade with 8 MB of RAM.)
A4: 7.89 by 11.44
B5: 6.72 by 9.81
#10 Envelopes: 3.84 by 9.10

IIg
US Letter : 8.11 by 10.79
Legal: 8.11 by 13.79 (Legal-size documents require 8 MB of

RAM to print with PhotoGrade.)
A4: 7.89 by 11.44
B5: 6.72 by 9.81
#10 Envelopes: 3.84 by 9.10

Specifications Paper - 10

Paper

Paper W eights

Cassette Sizes

Capacity In

Cassette feed:16-24 lb., single-sheet, photocopy bond
Manual feed:16-36 lb., letterhead and colored stock, standard-

weight transparency material, envelopes, and labels

US letter standard; legal, A4, B5, and envelope cassettes optional

Cassette:200 sheets Manual: single sheets
Envelope cassette:15 envelopes

Face-down tray:100 sheets Face-up tray:20 sheets

Use manual feed for letterhead, colored stock, standard-weight
transparency material, and labels.

Specifications Built-In Fonts - 11

Built-In Fonts

SC

NT, NTX, NTX-J

IIf, IIg

Times, Helvetica, Courier, and Symbol

Times, Helvetica, Helvetica Narrow, Courier, Symbol, Palatino,

ITC Avant Garde, ITC Bookman, New Century Schoolbook, ITC

Zapf Chancery, and ITC Zapf Dingbats

Times, Helvetica, Helvetica Narrow, Courier, Symbol, Palatino,

ITC Avant Garde, ITC Bookman, New Century Schoolbook, ITC

Zapf Chancery, ITC Zapf Dingbats, and Emulator.

Note:

Built-in fonts can be expanded using an optional font
expansion board. All LaserWriter II printers support
TrueType when using LaserWriter driver 6.1 or greater.

Specifications Environmental - 12

Environmental

Temperature

Humidity

Operating: 50–90.5°F (10–33°C)
Storage:38–95° F (3–35°C)

Operating: 20-80% relative humidity
Storage: 10-80% relative humidity

Printing: Under 60 dB(A)
Standby: Under 50 dB(A)

Specifications Electrical - 13

Electrical

Line V oltage

Power Consumption

US/Japan:100-115 V, 50-60 Hz
Europe/Australia:220-240 V, 50 Hz

Standby:
170 W (average)
Operating:
900 W maximum (115 V)
780 W maximum (220 V)
880 W maximum (240 V)

Specifications Physical - 14

Physical

Dimensions

Weight

Width: 20 in. (51 cm)
Depth: 18.9 in. (48 cm)
Height: 8.5 in. (21.6 cm)

46 lb. (21 kg)

K

Service Source

Troubleshooting

LaserWriter II

Troubleshooting IIf/IIg Diagnostic/ - 1

IIf/IIg Diagnostic

Set the rotary switch on the back of the printer to 4 and connect
the LaserWriter II Test Connector to the DB-25 serial port (or
simply jumper pins 4 and 22). Switch on the printer. Under
normal conditions, LEDs should flash during startup, and then fix
on the “diagnostic executing” configuration for about 2 minutes.
If no error is found, all LEDs flash and a page prints. If the LEDs
indicate an error, go to the appropriate topic in Flowcharts.

(Diagnostic Executing)

Fuser Assembly Error

Laser/Scanner Error

I/O Controller Board Error

Replace ROM #1

Replace ROM #2

Replace ROM #3

(No Error Found)

Replace SIMM #2

Replace SIMM #3

Replace SIMM #4

Replace SIMM #5

Replace SIMM #6

Replace SIMM #6

Replace SIMM #7

Replace ROM #4

Replace SIMM #1

After running this diagnostic, switch off the printer, remove the
Test Connector, and reset the rotary switch to its original setting.

Replace SIMM #8

Troubleshooting Capacitor Discharge - 2

Capacitor Discharge

When there is a failure of the fusing system, the DC controller
board shuts off current to the fuser roller heater and charges
capacitor C211 to prevent overheating. If there is a failure of the
fusing system, you must turn the power off for about 30 minutes
or manually discharge the capacitor before switching power back
on.

C211

DC Controller Board

Troubleshooting Capacitor Discharge - 3

Switch off and unplug the printer, and remove the bottom panel
and lower cover. Locate capacitor C211 on the DC controller
board. Carefully jumper the two wires at the base of the capacitor
using some kind of conductive tool, as shown on the next page.

Caution:

components neighboring the capacitor.

Note:

the capacitor: a flat blade screwdriver, paper clip, or aluminum
foil doubled over. The tool illustrated is a length of lead solder. It
has the advantage of being ductile and is less apt to damage the
controller board.

Take care not to damage the board tracings or the

There are many different tools that can be used to discharge

Troubleshooting Capacitor Discharge - 4

Capacitor C211

Troubleshooting Controller Board Readings - 5

Controller Board Readings

Voltage readings on the Canon SX engine controller board are
difficult to make and require accessing the underside of the
printer.

Rest the printer on the I/O board rails with the rear side facing
you and the near rail at the front edge of your work surface. If you
need to elevate the printer to get clearer access to the DC
controller board, use the bottom panel and lower cover.

Caution:

print cycle or while the clamshell is open.

The printer must be in an upright position during a

Troubleshooting Roller Diameters - 6

Roller Diameters

Repetitive printing defects can often be isolated by measuring the
tracking left by rollers. On the next page is a diagram that shows
all the rollers in the LaserWriter II that come into contact with
paper. The dimension given is the distance between tracks.

Troubleshooting Roller Diameters - 7

Transfer Guide Assembly
.5" (13 mm): roller to corona assy

1.5" (38 mm): upper metallic roller

1.75" (44 mm): lower black roller

Fuser Assembly

2.56" (65 mm): lower fuser roller

3.16" (80 mm): upper fuser roller

Toner Cartridge

2.0" (51 mm): developer roller

3.75" (95 mm): photosensitive drum

Troubleshooting Drum Check - 8

Drum Check

Interrupting a print cycle and inspecting the photosensitive drum
can help isolate the cause of print quality problems. If the image
on the surface of the drum exhibits the same problem as the
printed page, the fault is before the drum, probably somewhere in
the scanning system. If the image on the drum is okay, the fault is
after the drum, probably in the fuser assembly, transfer corona,
or high-voltage power supply.

Note:

Refer to “Roller Diameters” in this chapter for further

quick-check troubleshooting tips.

Troubleshooting Top-Cover Interlock - 9

Top-Cover Interlock

Defeating the top-cover interlock simulates a clamshell-shut
condition and is required in certain troubleshooting procedures.

You defeat this interlock by lodging a stiff, non-metallic insert
into the interlock switch. A plastic ball-point pen cap or folded
index card works well.

Troubleshooting Top-Cover Interlock - 10

Top-Cover Interlock

Troubleshooting Circuit Board Diagrams - 11

Circuit Board Diagrams

On the following pages are diagrams of the circuit boards and
high-voltage contacts listed below:

• LaserWriter IISC I/O board

• LaserWriter IINT I/O board

• LaserWriter IINTX I/O board

• LaserWriter IIf I/O board

• LaserWriter IIg board

• DC controller board

• Distribution board

• High-voltage contact

• Fuser board

Troubleshooting Circuit Board Diagrams - 12

LaserWriter IISC
I/O Board

ADB SCSI SCSI

Switch

SCSI

Troubleshooting Circuit Board Diagrams - 13

LaserWriter IINT
I/O Board

ROMs

ADB DIP

Switches

RS-232
RS-422

LocalTalk

Troubleshooting Circuit Board Diagrams - 14

LaserWriter IINTX
I/O Board

ROMs

ADB DIP

SCSI

Switches

RS-232
RS-422

LocalTalk

Troubleshooting Circuit Board Diagrams - 15

LaserWriter IIf
I/O Board

Pushbutton Switch

LocalTalk

RS-232
RS-422

SCSI

ROMs

SIMMs

Troubleshooting Circuit Board Diagrams - 16

LaserWriter IIg
I/O Board

Pushbutton Switch

LocalTalk

ROMs SIMMs

RS-232 SCSIEthernet
RS-422

Troubleshooting Circuit Board Diagrams - 17

DC Controller Board

J201

J203

J202

J212

J213

LED201

Cassette
Microswitches

Service Test Page Button
(see “Service Test Page” in Basics)

J210

J205

J209

Cover Interlock Switch

C211 (see “Capacitor
Discharge” in
Troubleshooting.)

J208

J207

J206

Troubleshooting Circuit Board Diagrams - 18

Distribution Board

Registration Clutch

Solenoid SL302

Drum Sensitivity Switch SW301
Drum Sensitivity Switch SW302

DC Power Supply

Paper Pickup Roller
Solenoid SL302

Paper-Out
Sensor
PS301

Manual-Feed
Paper Sensor
PS302

Distribution

BoardJ213

Troubleshooting Circuit Board Diagrams - 19

High-Voltage Contacts

Transfer Corona Contacts
(Underneath)

Primary Corona

Wire Contact

Developing Bias
Contact

Low Toner

Silver-Colored Screw

Sensor Contact

Primary Corona Grid Contact

Toner Cartridge Ground

Troubleshooting Circuit Board Diagrams - 20

Fuser Board (also known as Fuser PCA)

Delivery Sensor PS331

(opposite face)

Delivery

Sensing

Lever

To Thermistor TH1

71

J331

Preconditioning Exposure
Assembly Contacts

J333
J334

Troubleshooting Connector Locators - 21

Connector Locators

On the following pages are diagrams of the connectors listed below:

• Connector J103

• Connector J502

• Connector J601

Troubleshooting Connector Locators - 22

Connector J103 connects the fuser to the fuser safety PCA inside
the power supply block. If you measure continuity between the
two pins of J103, the fuser bulb and thermoprotector are intact.

Fuser Assembly
(Removed from Printer)

J103

J103

Troubleshooting Connector Locators - 23

Connector J502 connects the DC power supply with the power
supply block. This illustration shows the printer with the DC
power supply removed.

J502-1
J502-3

J502

Troubleshooting Connector Locators - 24

Connector J601 connects the high-voltage power supply to J211
on the DC controller board. This illustration shows the printer
with the high-voltage power supply removed.

J601-1

J601-8

J601

Troubleshooting Flowcharts - 25

Flowcharts

The flowcharts for this manual are contained in an interactive file
called “LaserWriter II Flowcharts.” This file has been derived
from the original version of Service Source but is a standalone
self-launching application. To launch this file, click the button
below..

Power Supply

Block

Noise
Filter

CB1

Upper

Fan

J152 1 2

Fuser
Safety
PCA

+24VDC

J103

1
2

Fuser Assembly

Thermo-Protector

TP1

HEATER

BULB

21TH1

Fuser PCA

J332

+24V

J334 J333

Preconditioning

TB

321

Exposure
Assy

TB

322

Toner Cartridge

J104

J502

Main

Motor

6 5 4 3 2 1

Optical

Fiber

J451

1
2

3

Laser

Diode PCA

4

J401

5
4
3

Scanning

Motor PCA

2

Laser/Scanner Assembly

1

B12

+5V

5
4

3
2

1

7
6
5

4
3
2
1

J201

J202

J203

FG
+5V

LDRV
PD

DSADJ

+24VA
GND
SCNCONT

GND(FG)
FG+
GND(FG)
FG-

B13

123

J101

AC-COLD

AC-HOT

11

33

F1

DC Power Supply

J3

GND

GND

+5V

+5V

-5V

12345678910111213

B14

B15

B16

Top Cover
Interlock

+24VDC

RESET

AA*BB*GND

REMOTE*

J212

J205

N/C

CMD*

N/C

A1

A2

A1

CPRDY*

A3A4A5A6A7A8A9

B2B3B4B5B6B7B8B9B1

I/O PCA

4

+24VB

+24VA

14

PRNT*

PCLK*

FAN (SB)

FSRD* (PK)

123

J208

SBSY*

RDY*

GND (BL)

BD*
A10

Paper

Delivery

J331

+24VA (R)

4

DC Controller PCA

CCLK*

RDY

B1

B3

B2

Connector PCA

B10

B11

A3A4A5A6A7A8A9

A2

Sensor

PS331

Precon-

ditioning

Exposure

Circuit

FSRTH(PK)

PEXP(Y)

STS*

1

2

+24V (R)

GND 24V(BL)

1

2

VSREQ*

PPRDY*

FG

76543

+5V(BR)

PDP*(SB)

GND(BL)5V

76543

J206

J205

VDO*

VSYNC*

CBSY*

B4B5B6B7B8B9B10

A10

FG

A11

PS301

PS302

Manual-

J209

FG

1

A12

Paper

Sensor

Feed Paper

Distribution PCA

+5V

Out

GND

+5V

GND

9876543

MPFS*9PEMP*8+5V7GND6+24V5CPUD4REGD3CSENS2*2CSENS1*1+24B(R)8GND(BL)7DBDC*(V)6TSENS(Y)5DBAC*(V)4HV10N(GY)

SG

2

A13

A14

+24V

tration

Regis-

Roller

SL301

Pickup

Solenoid

+24V GND

J213

+24VANCNC

DBDC*

-5V

DBAC*

GND

HV1ON*

12345678910111213141516171819

J330

A15

A16

SL302

Solenoid

Drum-

Sensitivity

2

J210

+5V

HVTON*

GND

SW302

SW301

Switches

1

+5VA

TPA*

TSTPT*

TPB*

J601

RDYINH*

TSTPTE*

J331

TB

604

TB

605

TB

Primary

Corona

Discharging

Pins

8765432

J211

LPCK*

CSNT1*

SCNON*

CSNT2*

20

RDYL*

POUT*

+5V

JAML*

Connector PCA

TEMPL*

603

J602

Transfer
Corona

Primary Corona Grid

HVRST(PK)

HVTON(SB)

3

2

J207

+24VA

GND

3

Ready/Wait LED

Paper-Out LED

2

1

Paper-Jam LED

5

Status Panel

Low-Toner LED

4

1

1

1

2

1

J603

Developer
Bias
(AC&DC)

Lower

J603

High
Voltage
Power
Supply

Fan

TB

601

TB

2

602

Sensor

Low T oner

LaserWriter II

Wiring Diagram 110V

K

Service Source

T ak e Apart

LaserWriter II

Take Apart I/O Board - 1

I/O Board

No preliminary steps are
required before you begin
this procedure.

Note:

The I/O board may
require configuration prior
to installation in the the
printer. For more
information, refer to “I/O
Board Installation” in
Additional Procedures.

Note:

If the I/O board is
removed from the printer,

I/O Board

the LEDs no longer function.

Take Apart I/O Board - 2

1 Loosen the two screws

that secure the I/O board
to the chassis.

2

Caution:

Handle the
board by the metal
bracket only.

I/O Board

Carefully slide the I/O
board out of the printer.

Take Apart Base Unit - 3

Base Unit

Lower Fan

I/O Board Shield Plate

Lower Cover

Bottom Panel

Before you begin, remove
the I/O board.

Note:

This procedure covers
the take apart of the bottom
panel, I/O board shield
plate, lower cover, and the
lower fan.

Caution:

to remove the toner
cartridge prior to turning
the printer over.

Ê

Always remember

Take Apart Base Unit - 4

1 Place the printer on its

back on a padded work
surface.

2 Remove the seven screws

that secure the bottom

Bottom Panel

panel to the metallic
lower cover.

3 Remove the bottom

panel.

Take Apart Base Unit - 5

4 Remove the two screws

that secure the I/O board
shield plate to the lower
cover. Remove the
shield plate.

I/O Board

Shield Plate

Take Apart Base Unit - 6

5 Remove the nine screws

that secure the lower
cover to the printer
chassis.

6 Lift the lower cover and

slide it free at the I/O

Lower Cover

board guide rails.

Take Apart Base Unit - 7

Lower Fan

Lower Fan

Note:

If you need to remove
the lower fan, perform the
following procedure.

1 Disconnect the fan cable

from DC controller
board connector J207.

2 Remove the four screws

that secure the fan to the
chassis.

3 Remove the fan and the

fan bracket.

Take Apart Controller Boards - 8

Controller Boards

Connector Board

DC Controller Board

Before you begin, remove
the following:

• I/O board

• Base unit

Note:

This topic covers the
take apart of the DC
controller board and the
connector board. You may
perform these procedures in
any order. Neither
procedure requires that the
other be done first.

Take Apart Controller Boards - 9

DC Controller Board

1 Remove the two screws

that secure the I/O board
guide rail to the chassis

DC Controller Board

I/O Board
Guide Rail

and move the guide rail
away from the DC
controller board.

Take Apart Controller Boards - 10

Note:

Cover Interlock
Switch Actuator

Cabling is not shown
for clarity.

2 Remove the two screws

that secure the DC power

DC Power Supply
Connector J212

supply and distribution
board connectors.

3 Loosen the screw that

secures the lower-

Distribution Board
Connector J213

cover interlock switch
actuator to the chassis
and lift off the metal
actuator.

Take Apart Controller Boards - 11

4 Disconnect the following

cables:

• Fuser assembly board
cable from J206

• Lower fan cable from
J207

• Power supply block
cable from J208

• High-voltage power
supply cable from
J211

• Scanning motor
assembly cable from
J203

• Laser diode assembly
cable from J202

• Optical fiber cable
from J201

Take Apart Controller Boards - 12

5 Remove the two screws

that secure the power
lugs to the connector
board.

6 Remove the four screws

that secure the DC
controller board to the
chassis.

Power Lugs

Take Apart Controller Boards - 13

7

Note:

The two DC power
supply connectors offer
some resistance when
you are removing the DC
controller board. If you
want to alleviate this
problem, remove the
four screws that secure
the connector to the
board, remove the cables
from the connector, and
then proceed with
removing the board. Be
sure that you screw the
connector back in before
returning the controller
board to Apple.

Take Apart Controller Boards - 14

Jumper

Carefully grasp the DC
controller board by the
edges and pull the board
firmly up and away from
the connector board.

8 Remove the jumper at

J209, if one is present.

Take Apart Controller Boards - 15

Connector Board

1 Disconnect the status

Power Lugs

Connector

Board

panel cable from
connector J331.

2 Remove the two screws

that secure the power
lugs to the connector
board.

3 Remove the three screws

that secure the connector
board to the chassis.

Take Apart Controller Boards - 16

4 Remove the screw at the

corner of the DC
controller board nearest

Screw

the power lugs.

5 Lift the corner of the DC

controller board slightly
and slide out the
connector board.

Connector

Board

Take Apart Cover Set - 17

Cover Set

Cover Set

No preliminary steps are
required before you begin
this procedure.

Note:

This procedure covers
the take apart of the cover
set, including the release
button and LED status panel

Take Apart Cover Set - 18

1 Remove the four screws

that secure the cover set
to the printer.

Take Apart Cover Set - 19

2 Depress the release

button and open the top
cover.

3 Remove the three

interior screws along

Release
Button

the rim of the cover set.

Take Apart Cover Set - 20

4 Remove the two interior

screws that secure the
cover set bracket to the
chassis.

Take Apart Cover Set - 21

5

Note:

If you need to
monitor status panel
lights when the cover is

LED Status Panel

off, don’t disconnect the
connector. Simply
remove the two screws
and lift the whole status
panel off the cover.

Lift up the cover set and
remove it far enough to
disconnect the connector
from the LED status
panel.

Take Apart Cover Set - 22

6 Set aside the cover set.

Note:

The cover set is made
up of front, rear, upper
right, and lower right
panels. Each panel can be
taken apart by removing the
appropriate screws.

Release Button

1 To remove the release

button, squeeze the

Release Button

arms of the button and
remove it from the
upper right panel.

Take Apart Clamshell Detachment - 23

Clamshell

Clamshell

Detachment

Before you begin, remove
the following:

• Cover set

• Fuser assembly

Note:

The clamshell is what
hinges upward when you
open the printer. It is not
available from Apple as an
assembly, but you may need
to remove it in the course of
removing other assemblies.

Take Apart Clamshell Detachment - 24

1 Remove the four screws

that secure the left and
right hinge assemblies
to the chassis and lift off
the upper clamshell
(right hinge assembly
not shown).

Left Hinge
Assembly

Replacement Note:

Cradle
the clamshell in an upright
position and secure the right
hinge assembly to the
printer chassis. Then
secure the left hinge
assembly. Make sure the
screws are tight.

Take Apart Laser/Scanner Assembly - 25

Laser/Scanner Assembly

Laser/Scanner Assembly

Before you begin, remove
the cover set.

Note:

The LaserWriter II
laser/scanner assembly is
available only as an integral
assembly. No subcomponent
is available from Apple and
no adjustments to laser
power circuitry can be
made. See “Laser Power
Output Check” under
Additional Procedures for
measurement procedures.

Take Apart Laser/Scanner Assembly - 26

1 Disconnect the cable

from laser diode board
connector J451.

Take Apart Laser/Scanner Assembly - 27

2 Open the cover that

accesses the scanning
motor board and
disconnect the scanning
motor cable.

Cover

Scanning Motor Cable

Take Apart Laser/Scanner Assembly - 28

3 Remove the screw on the

Optical Fiber Cable

optical fiber cover and
open the cover.

Cover

4 Carefully lift the optical

fiber cable up and out of
its slot in the laser/
scanner assembly.

Replacement Note:

Make
sure that the collar on
the optical fiber seats
properly in the slot
before closing the cover.

Take Apart Laser/Scanner Assembly - 29

5 Remove the four long

screws that secure the
laser/scanner assembly
to the main body block.

6 Remove the laser/

scanner assembly.

Note:

Make sure that the
optical fiber and laser
harness cables are removed
when you return a defective
laser/scanner assembly to
Apple.

Take Apart Fuser Assembly - 30

Fuser Assembly

No preliminary steps are

Fuser Assembly

required before you begin
this procedure.

Note:

The fuser assembly
consists of several orderable
components and sub­assemblies (see Illustrated
Parts).

Take Apart Fuser Assembly - 31

Note:

This procedure covers
only the removal of the
fuser assembly from the
printer. The topics that
follow this one address
further disassembly of the
fuser assembly:

• Fuser Delivery Assembly

• Fuser Heater Bulb

• Delivery-Sensing Lever

1 Depress the release

button and open the top
cover.

Take Apart Fuser Assembly - 32

2 Remove the four screws

Fuser

Assembly

that secure the fuser
assembly to the chassis.

3 Lift the fuser straight up

out of the printer.

Fuser

Board

Replacement Note:

Make
sure that the 7-pin
connector on the fuser
board mates properly
with the receptacle.

Note:

Before returning the
fuser assembly to Apple,
remove the cleaning felt and
replace it with the roller
separators that come with
the exchange unit.

Take Apart Fuser Delivery Assembly - 33

Fuser Delivery Assembly

Before you begin, remove

Fuser

Delivery

Assy

the fuser assembly.

Note:

The fuser delivery
assembly is an orderable
subassembly of the fuser
assembly. Its function is to
separate the page as it exits
the fuser rollers and to feed
it toward the delivery tray.

Take Apart Fuser Delivery Assembly - 34

1 Open the fuser delivery

assembly.

Fuser Delivery

Assembly

Tension Spring

2 Unhook the two tension

springs that connect the
fuser delivery assembly
to the fuser assembly.

3 Remove the two screws

that secure the fuser
delivery assembly to the
fuser assembly.

4 Remove the fuser

delivery assembly.

Take Apart Fuser Delivery Assembly - 35

Delivery Rollers

Note:

The delivery rollers
are the white serrated
rollers within the fuser
delivery assembly.

C-Rings

C-Ring

1 If you need to replace a

delivery roller, remove
the three C-rings that
secure the delivery
roller shaft to the fuser
delivery assembly.

Take Apart Fuser Delivery Assembly - 36

2 Push the bushings

toward the center of the
delivery roller shaft.

Bushing Bushing

Delivery Roller Shaft

Take Apart Fuser Delivery Assembly - 37

3

Note:

Be careful not to
lose the tiny delivery
roller gear pin that
falls out when you
remove the gear in the
following step.

Slide the delivery roller
shaft away from the
gear arm and rotate the
gear arm off the shaft.

Delivery Roller Shaft

Take Apart Fuser Delivery Assembly - 38

4 Remove the delivery

roller gear from the
delivery roller shaft.

Delivery Roller Gear

Take Apart Fuser Delivery Assembly - 39

5

Note:

The delivery
rollers rest loosely
within slots in the fuser
delivery assembly and
may fall out when you
remove the roller shaft.

Remove the delivery
roller shaft and lift out
the delivery roller.

Delivery

Rollers

Take Apart Fuser Heater Bulb - 40

Fuser Heater Bulb

Before you begin, remove

Fuser Heater Bulb

the fuser assembly.

Note: The fuser heater bulb
is an orderable sub­component of the fuser
assembly. It provides the
heat necessary to fuse toner
to paper.

Take Apart Fuser Heater Bulb - 41

1 Open the fuser delivery

assembly.

2 Loosen the screw (1)

that secures the fuser
cover to the fuser
assembly.

3 Lift the fuser cover and

the fuser cleaning felt.

4 Remove the screw (2)

that secures the left
contact cap to the fuser
assembly. Lift off the

Fuser Cover

cap.

Left Contact Cap

Cleaning Felt

(Inside)

Take Apart Fuser Heater Bulb - 42

5 Remove the two screws

that secure the fuser
board to the fuser
assembly.

6 Note: The fuser board

will hang loosely from
the fuser assembly after
the following step. Be
careful when handling
either part.

Detach the fuser board
from the fuser assembly.

Take Apart Fuser Heater Bulb - 43

7 Remove the three screws

that secure the left
terminal mount to the
fuser assembly.

8 Remove the terminal

mount.

Left Terminal Mount

Take Apart Fuser Heater Bulb - 44

9 Remove the screw that

secures the left heater
support to the fuser
assembly. Remove the
support.

Left Heater Support

Take Apart Fuser Heater Bulb - 45

10 Remove the screw that

secures the right
contact cap to the fuser
assembly. Remove the
cap.

Replacement Note:
Before replacing the
contact cap, make sure
that the heater bulb
grounding lead wraps
around the positioning
posts on top of the

Right Contact Cap

terminal mount.