Apple Laserwriter 8500 Service Manual

K
Service Source

LaserWriter 8500

K
Service Source

Overview

LaserWriter 8500

About This Overview

This overview briefly describes the servicing issues of the LaserWriter 8500, especially those that distinguish it from earlier Apple laser printers.
360 Degree View
LaserWriter 8500 Basic Configuration
Overview General - 2

General

The LaserWriter 8500 is a 600 dpi, 20 ppm monochrome laser printer that is capable of printing onto paper up to 13 x 20 inches in size. In its basic configuration, the printer has a capacity of 650 sheets, the standard cassette holding 500 sheets (as compared to the 250 typical in earlier printers), the multipurpose tray holding 150.
There are several options available for the printer, including a duplexer unit (for two-sided printing), a 500-
LaserWriter 8500 with
Duplexer and Sheet Feeder
360 Degree View
sheet feeder, and an envelope cassette.
Overview Duplexer - 3

Duplexer

The duplexer is an inverted L-shaped feeder that mounts
Duplexer

Paper Path

Through Duplexer
onto the upper rear of the printer. Once installed, (even simplex) diverts into and exits from the duplexer.
This is unlike the LaserWriter 12/640 PS, which employs a solenoid-actuated diverter controlled through software. The operative element in the LaserWriter 8500 is the exchange chute, located in the fuser assembly. The exchange chute is actuated (i.e. locked in place) during installation of the duplexer.
After the first pass of a duplex page, the paper partially exits the duplexer delivery rollers. The rollers then reverse and the paper feeds back down through the duplexer and into the printer engine, in preparation for imaging of the second side. The paper then exits through the duplexer into the delivery tray.
all
paper
Overview Paper Path - 4
The duplexer derives its power from the printer engine but has its own motor to generate mechanical drive.

Offset Function

The duplexer has a job separation feature that allows print jobs to be stacked offset (i.e. staggered left-to-right) in the delivery tray. Job separation is set in the Apple Printer Utility.
Note
: Due to cost considerations, the offset function has been incorporated into the duplexer instead of the printer engine. Offsetting and duplex printing are otherwise unrelated to one another.
The offset motor in the duplexer generates the mechanical drive for offsetting paper.
Overview Sheet Feeder - 5

Sheet Feeder

As with the LaserWriter 16/600 PS and LaserWriter 12/ 640 PS designs, the sheet feeder fits squarely beneath the printer to form a dual front-loading cassette arrangement. Unlike those models, however, you can stack two feeders
Sheet Feeder
beneath the printer, for a total auxiliary capacity of 1000 sheets. Also unlike those models, the sheet feeder and the engine use identical cassettes in the LaserWriter 8500.
The sheet feeder derives its power and mechanical drive from the printer engine.
Overview Form Factor - 6

Form Factor

C
To achieve a reasonably compact form factor, the tail end of the cassette has been designed to extend out from the engine footprint (A). Consequently, the pickup rollers feed from
D
A
B
Printer Cross-Section
Note: Diagram shows printer with long cassette and over­size (11 x 17 inch or A3) paper installed.
the insertion end of the cassette (B), similar to the Laser­Writer II. This arrangement influences the architecture of the printer in the following ways.
1 Because pickup occurs deep within the printer, all
mechanical drive elements are arranged vertically along the rear (C), resulting in a simple C-shaped paper path. This vertical arrangement yields a compact, low­maintenance gear train, consisting at its essence of one gear assembly driven by one central motor.
2 You can stack letter-sized paper on the multipurpose
tray and shut the cover (D), thus hiding that paper from view inside a multipurpose “compartment.”
Overview Form Factor - 7
3 The design of the cassette bottom plate (A) is new.
A
C
Below the plate, three springs provide upward pressure that forces the paper against the pickup rollers. (Only two of the springs are activated when the width guides
B
C
(B) are set for narrower paper). In most printers, the bottom plate receives constant uniform pressure from the springs. As you insert the cassette, the paper snugly and passively presses against the pickup rollers.
With this printer, however, the bottom plate must stay down during insertion to avoid snagging. The springs are released, and the bottom plate elevated against the pickup rollers, only when the cassette is fully inserted.
This spring release is actuated by a latch on each side of the cassette near the leading edge (C). See “Cassette” in the Basics chapter for more information.
Overview Paper Orientation - 8
Long-Edge Feed
(LEF)
Short-Edge Feed
(SEF)
Feed
Feed

Paper Orientation

The paper path is wide enough to print letter or A4 sized paper in long-edge feed (LEF) mode. LEF mode is recom­mended as it achieves the fastest 20 ppm throughput and optimizes duplex printing.
Note
: The cassette automatically senses paper orientation. The multipurpose tray does not. Printing in short-edge feed (SEF) mode from the multipurpose tray may produce undesirable results.
Paper orientation and how best to load paper can be confusing, especially when talking with customers over the phone. It is further complicated when printing duplex jobs. Keep in mind the following tips:
• Use the LEF and SEF terms when talking about how paper
is loaded. These are the terms found in the user manual.
Overview Paper Orientation - 9
• The terms “portrait” and “landscape” are best used only when talking about how a printed page is to be formatted. Remember that LEF mode, for example, can result in either a landscape or a portrait formatted page.
• Load letterhead face-up.
• As you stand facing the printer: the top of the page is on the left for LEF portrait, and on the near side for LEF landscape.
LEF Paper Orientation
Overview Service Test Page - 10

Service Test Page

A service test page, sometimes called an engine test page, is a page whose description resides in firmware on the DC controller board. Successful printing of a service test page confirms the operation of the print engine. Of equal impor­tance, if a print quality problem appearing on a normal page
Service Test Page
also appears on the service test page, the I/O controller board is proven good and should not be swapped.
Test Page Button
There are two ways to print a service test page on the Laser­Writer 8500.
1 If the I/O board is installed, use a paper clip to press the
test page button. This button is accessible through a small unmarked hole at the top of the I/O bracket.
Note
: Use this button liberally, both in person and when
troubleshooting with customers on the phone. It is your
Overview Service Test Page - 11
Test Page Jumper
first line of defense in isolating faults between the I/O board and printer engine.
2 If the I/O board and shield have been removed from the
printer, you can print a service test page by jumpering the two pins of connector P23 on the DC controller board.
Overview RAM Memory - 12

RAM Memory

The LaserWriter comes with 16 megabytes (MB) of RAM soldered onto the I/O controller board. There is one SIMM slot available for installing additional RAM. The following table lists the memory requirements and supported paper sizes for duplex printing and PhotoGrade.
Memory Duplex Printing PhotoGrade Use both features at once?
16 MB Letter, A4, B4, legal Letter, A4, B5 No
20 MB Letter, A3, A4, B4, Up to ledger and A3 Yes; up to letter and A4
legal, ledger
24 MB Letter, A3, A4, B4, Up to Japan Standard Yes; up to legal
legal, ledger and Japan Larger
32 MB Letter, A3, A4, B4, All supported paper Yes; up to B4
legal, ledger sizes
48 MB Letter, A3, A4, B4, All supported paper Yes; all supported paper
legal, ledger sizes sizes
Overview SIMM Sizes and Speeds - 13

SIMM Sizes and Speeds

Size Configuration Speed Connector type 4 MB SIMM 1 M X 32 bit (one 4 MB bank) 70 ns or less 72-pin 8 MB SIMM 2 M X 32 bit (two 4 MB banks) 70 ns or less 72-pin 16 MB SIMM* 4 M X 32 bit (one 16 MB bank) 70 ns or less 72-pin 32 MB SIMM* 8 M X 32 bit (two 16 MB banks) 70 ns or less 72-pin
* Must have a 2 KB row (11 bit x 11 bit) refresh rate. 16 MB SIMMs with a 4 KB row (12 bit x
10 bit) refresh rate are not compatible with the printer.
Overview Miscellaneous - 14

Miscellaneous

Full-Stack Sensor

When the delivery tray is full of paper, the printer stops accepting print jobs and the controller reports an error message to the host computer. Sensing of delivery tray capacity is done through the full-stack sensor located just above the delivery rollers.
With a duplexer installed, the duplexer full-stack sensor
Actuator for
Full-Stack Sensor
assumes this function. The parts used in the duplexer actuator and the printer actuator are
not
interchangeable.

Other Sensors and Interlocks

All other sensors and interlocks are similar to previous printers and will be familiar to the experienced technician. See “Sensing System Locator” in the Basics chapter for a
Overview Miscellaneous - 15
comprehensive diagram.
There is also a mechanical interlock that disengages the fuser assembly drive train when the top cover is open (to facilitate removal of paper jams). See “Top Housing and Xerographics” in the Basics chapter.

Point-of-Sale (POS) Button

The Ready LED is also a button that actuates a microswitch on the status panel board. If you hold this LED during printer startup, the printer will enter the special POS state (or exit from POS if POS is currently enabled). You can also make these settings through the Printer Utility.
During POS state, the ready LED flashes two shades of green
Demonstration Page
instead of the normal steady green. When you press the ready LED thereafter, a special demonstration page will print. While in POS state, the energy saving feature is
Overview Miscellaneous - 16
disabled, but in all other ways, the printer is network­aware and will perform just as it does in ready state.
Voltage-Specific Parts
Four parts in the printer are available in both 110V and 220V versions:
• Power supply
• Fuser assembly
• Transport chute assembly
• DC controller board
Note
: The DC controller board, though universal in
previous printers, is not in the LaserWriter 8500. The second version of this board satisfies European
Economic Community requirements and has made possible some localization of controller board firmware (default paper size for the multipurpose tray, for example).
Overview Miscellaneous - 17

Density Adjustment

Density Adjustment Dial
On the left side of the multipurpose tray compartment, there is a density adjustment dial. This dial changes the DC component of the development bias voltage supplied by the high-voltage power supply. The dial adjusts the threshold voltage, in effect changing the background density across the entire imageable page.
A second method of density adjustment is through the Apple Printer Utility, which adjusts the laser power output. In effect, this adjusts the density of the printed pixels.
K
Service Source

Basics

LaserWriter 8500
Basics Function of Main Components - 1

Function of Main Components

This topic describes the function of the following components of the LaserWriter 8500.
•Cassette
•Cassette Feed Components
•Manual Feed Components
•Paper Transportation
•Fusing and Paper Exit
•Frame and Drive
•Top Cover and Xerographics
•Electrical

Cassette

Paper Width Guides
The paper width guides are adjusted left-to-right to accommodate different paper widths. They contact the left and right sides of the paper stack and hold the paper stack in place in the crosswise direction.
The left and right snubbers (paper separating claws) at the leading edge of paper allow only one sheet of paper to be fed from the cassette into the printer. The snubbers move together with the paper width guides.
Pressure Plate Springs
Two pressure springs act against the bottom plate when paper width is less than 8.5 inches (216 mm). When the paper width is greater, additional forced is deemed necessary and a third pressure spring is released against the bottom plate. The mechanism that releases or contains the third spring is controlled by the paper width guides.
Bottom Plate Assembly
Left Width Guide
Size Cams
Pressure Plate Springs
Paper End Guide
Right Width Guide
Basics Function of Main Components - 2
Paper End Guide
The paper end guide can be adjusted front-to-rear to accommodate different paper lengths. It is in contact with the trailing edge of the paper stack.
When the paper end guide is adjusted, the size cams on the left side of the cassette rotate into a unique pattern of projections and gaps. When you insert the cassette, the position of the cams align with actuators that are housed in the printer’s left cassette guide assembly. The actuators correspond to four microswitches on the cassette feed board.
Cassette
Cassette Feed Board
Size Cam
Size Actuator Size Switch
Size Cam
Size Actuator Size Switch
Cassette Feed Board
Cassette Latches
On each side near the leading edge of the cassette are two cassette latches. When the cassette is outside the printer, these latches hold the bottom plate down against the force of the pressure plate springs. As the cassette is inserted, the latches release and the bottom plate elevates.
Bottom Plate Assembly
Cassette
Right Cassette
Latch
Bottom Plate Assembly
Cassette Guide
(in Printer)
Basics Function of Main Components - 3

Cassette Feed Components

Turn Clutch
Cassette Feed Solenoid
and Feed Gear
Cassette Feeder Board
The feeder board has the paper size microswitches (see previous topic) and serves as a relay board for the signals between the cassette feed and the DC controller board.
Cassette Paper-Present Sensor and Actuator
This sensor detects the presence of paper in the cassette.
Cassette Feeder Board
Cassette Paper-Present Sensor and Actuator
Cassette Feed Solenoid and Feed Gear
When the feed solenoid is actuated, the feed gear is releases and turns to engage with the feed idler gear. The feed gear then begins to rotate, causing the pickup rollers to rotate. After one revolution, the feed gear disengages from the feed idler gear and is latched by the pawl of the feed solenoid.
Turn Clutch
The turn clutch is an electromagnetic clutch that switches on and off the drive power to the lower and upper feed rollers.
Lower and Upper Feed Rollers
These rollers have an integral metal shaft/rubber roller design. Drive to the rollers is controlled by the turn clutch so that the rollers start feeding from the pickup area and stop feeding at the registration sensor.
When the engine receives a /PRFD signal from the controller, the engine stops feeding at the registration sensor and resumes when it receives a subsequent /START signal. If the / START signal is received before the paper reaches the registration position, the printer will feed the paper continuously without stopping the rotation of the feed rollers.
Pickup Rollers
Rotate and feeds one sheet of paper each time the cassette feed solenoid is actuated.
Basics Function of Main Components - 4

Manual Feed Components

Manual Feed
Sensor Assembly
Toner Sensor
Manual Feed Guide Tray
Manual Feed Paper-Present Sensor
Manual Feed Guide Tray
The manual feed guide tray is the pressure plate and width guide for manual feed paper. During standby the tray is held down by the pickup roller assembly cams. When the paper is about to feed, the cams move off the tray due to the rotation of the pickup roller assembly. The manual feed guide tray is therefore pressed up by the two pressure springs and the paper is pressed against the pickup roller.
Manual Feed Paper-Present Sensor
Part of the manual feed sensor assembly, this sensor detects the presence of paper in the manual feed compartment.
Toner Sensor
Also part of the manual feed sensor assembly, this sensor detects low toner by responding to the magnetism of the toner in the cartridge.
Basics Function of Main Components - 5

Paper Transportation

Transfer Roller Assembly
Transport Chute Assembly
Transfer Roller Assembly
The transfer roller is in contact with the drum in the toner cartridge. The roller is driven by the drum gear so that the roller surface moves at the same speed as the drum surface.
The transfer roller applies a positive charge to the back side of the paper when the paper travels between the roller and the drum. The negatively charged toner image transfers from the drum surface to the front side of the paper because it is attracted by the positive charge on the back side of the paper.
Transport Chute Assembly
Transport Chute Assembly
Photosensitive Drum
Detack Saw
Transfer Roller
Toner
Cartridge
Registration Actuator
Registration Sensor
Rear Chute Assembly
Rubber Registration Roller
Metal Registration Roller
Pickup Roller
Separation Pad
Included in the transport chute assembly are the following components.
Pickup roller assembly
: Consists of two pickup rollers, three core rollers, pickup cams, and the shaft. It rotates one turn each time the manual feed pickup solenoid is actuated, and feeds one sheet of paper from the manual feed compartment.
Pickup solenoid and pickup gear
: When the pickup solenoid is actuated, the pickup gear is released and turned by the pulling force of the pickup spring to engage with the opposite gear in the main gear assembly. The pickup gear then begins to rotate, causing the pickup roller assembly to rotate. After one revolution, the pickup gear disengages from the opposite gear because of its sector-shaped cutout and is latched by the pawl of the feed
Basics Function of Main Components - 6
solenoid.
Separation pad assembly
: Prevents extra sheets of paper from being fed by the friction
between the paper and the rubber of the separation pad.
Rear chute assembly
: Guides the paper fed from the cassette between the metal and rubber
registration rollers.
Metal registration roller and rubber registration roller
: The rotation of these rollers is controlled by means of the registration clutch assembly so as to register the paper with the image on the drum.
Registration sensor
: Detects the arrival and departure of the paper at the registration
position.
T ransfer r oller bearing
: Applies the transfer voltage from the high-voltage power supply to
the transfer roller assembly.
Detack saw
: Imparts a negative charge to the back side of the paper, partially neutralizing
the positive charges, so that the paper can peel off the drum.
Duplexer
The duplexer derives its mechanical drive from the duplex motor. The offset motor generates the lateral drive for job separation (left-to-right staggering of paper in the delivery tray).
Offset Gear
Gear B
Gear A
Drive Belt
Duplex Motor
Duplexer
Gear B
Gear C
Gear D
Pulley Gear
Pulley Gear
Basics Function of Main Components - 7

Fusing and Paper Exit

Fuser Assembly
Full Stack Sensor and Actuator
Exit Sensor and Actuator
Thermostat
Temperature Sensor Assembly
Pressure Roller
Thermal Fuse
The fuser assembly houses all components of fusing (the permanent fixing of toner to paper by means of heat and pressure), as well as components for paper delivery.
Fuser Bulb
(Inside Heat Roller)
Heat Roller
The heat roller is a hollow metal tube that applies heat to the paper passing between it and the pressure roller. The heat is generated by the fuser bulb inside the heat roller. This heat melts the toner on the paper.
Pressure Roller
The pressure roller is a solid, sponge rubber-coated metal shaft that presses the paper against the heat roller. The pressure helps bond the toner to the paper.
Heater Assembly
The heater assembly consists of the fuser bulb and the wiring and connectors attached to the ends of the bulb.
Temperature Sensor Assembly
The temperature sensor assembly is a thermistor whose resistance varies sharply with a change in temperature. This sensor is held in contact with the heat roller surface and monitors the temperature thereof. The signal from this sensor is used to maintain the temperature of the heat roller surface within the specified range by switching the power to the heater bulb on and off. The signal is also used for the first-stage overheat protection.
Thermostat
The thermostat is part of the heater bulb circuit ad functions as the second-stage overheat
Basics Function of Main Components - 8
protection. If the temperature sensor assembly fails to prevent a fuser overheat, the thermostat opens and power is cut to the heater bulb.
Thermal Fuse
Also a part of the heater bulb circuit, the thermal fuse functions as the third-stage overheat protection. If both the first and second stages fail to prevent a fuser overheat, the thermal fuse opens and power is cut to the heater bulb.
Heat Roller Diode
There is a negative charge that builds up on the heater bulb. This charge can disturb the toner image on the paper during fusing. The heat roller diode grounds this charge.
Full Stack Sensor
Full Stack Actuator
Exit Sensor
Exit
Chute
Roller
Exit Actuator
Heat Roller Finger
Fuser Assembly
Heat Roller
Pressure Roller
To Duplexer
Exchange Chute
Heat Roller Fingers
These fingers work in conjunction the non-stick coating of the heat roller to peel the leading edge of the paper from the roller.
Exit Sensor
The exit sensor detects the arrival and departure of the paper on the delivery side of the heat roller.
Full Stack Sensor
The full stack sensor detects when the delivery tray is full of paper.
Exchange Chute
The installation of an optional duplexer locks the exchange chute into a position so that all paper is directed up into the duplexer.
Basics Function of Main Components - 9

Frame and Drive

Main Motor
Registration Clutch
Assembly
Main Gear Assembly
Paper-Handling Gear Assembly
Main Motor
Generates all the drive power for the printer and optional sheet feeder.
Main Gear Assembly
Distributes drive power from the main motor to the fuser assembly, toner cartridge, paper handling gear assembly, registration clutch assembly, and pickup gear.
Paper Handling Gear Assembly
Transfers the drive power from the main gear assembly to the feed idler gear and to a second gear within the main gear assembly.
Registration Clutch Assembly
An electromagnetic clutch that switches the drive power on and off to the two registration rollers at a specified time after the registration sensor has detected the arrival of the paper. This clutch actuates momentarily after the paper arrives at the registration rollers to allow the feed rollers to remove any skew induced during paper feed.
Basics Function of Main Components - 10

Top Housing and Xerographics

Guide Arm and Fuser Guide Lever
Fuser Guide
Fuser Assembly
Lever
Top Cover
Main Gear Assembly
Front
When the top cover opens, the fuser guide lever presses down on the floating idler gear at the top of the main gear assembly, thus disengaging the fuser assembly from the gear train. This makes removal of paper jams from the fuser much easier. When the top cover is closed, the floating idler gear springs upward to mate the fuser gearing to the main gear train.
Cartridge Sensor Assembly
Cartridge-Present Switch LD Switch
Cartridge Sensor Assembly
Toner
Cartridge
Front
The cartridge sensor assembly houses the two switches below.
Cartridge-present switch
: The signal from this switch stops printer operation when the
toner cartridge is absent or the top cover is open.
Basics Function of Main Components - 11
Laser-diode (LD) switch
: This switch opens the laser diode circuit when the toner cartridge is absent or the top cover is open. The LD switch protects users against exposure to the laser light.
Toner Cartridge
The toner cartridge consists of five major components.
Photosensitive drum
: An aluminum cylinder with a surface coating of photoconductive material. The photoconductive coating holds an electrical charge, and allows the charge to flow through the thickness when exposed to light.
Bias charge roller (BCR)
: Places a uniform electrical charge on the drum surface, erasing
any charging patterns remaining from the previous cycle.
Magnetic roller
: Holds a thin layer of toner on its surface and transports it to the gap between the drum and the magnet roller. Toner is supplied to the magnetic roller by two agitators inside the toner compartment.
Charging and metering (CM) blade
: Spreads a thin layer of toner on the magnetic roll and
gives toner a negative charge.
Cleaning blade
: Scrapes the toner off the drum surface that is remaining after the transfer stage.
Laser/Scanner Assembly
Laser Diode Assembly
Front
Scanner Mirror
M
L
MM
L = Lens
L
Laser/Scanner Assembly
SOS Board
Photosensitive Drum
M
M = Mirror
SOS = Start of Scan
The laser/scanner assembly scans a light beam onto the surface of the photosensitive drum. This assembly consists of three major components: the laser diode, the scanning mirror, and the start-of-scan (SOS) board.
Basics Function of Main Components - 12

Electrical

Fuser Access Cover
Actuator
Fuser Cover
Interlock Switch
Actuator
Top Cover
Top Cover
Interlock Switch
Top Cover Interlock Switch
The top cover interlock switch is a safety switch that interrupts the supply of 24 VDC from the power supply to the DC controller board whenever the top cover is open. This switch also causes the power supply to interrupt AC line voltage to the fuser assembly. The switch is located inside the left cartridge guide and is actuated by the nylon tip at the end of the laser/scanner actuator rod.
Fuser Cover Interlock Switch
A safety switch that stops operation of the main motor, the laser/scanner assembly, and the fuser whenever the fuser access cover is open. The switch is located on the right side of the fuser access cover opening.
Fan
High-Voltage Power Supply
DC Controller Board
Print Density Adjustment Knob (Service Access Side)
Power Supply
Fan
The fan exhausts the air inside the printer to prevent an excessive heat caused by the fuser assembly. There is one fan in the LaserWriter 8500.
Power Supply
The power supply produces regulated low DC voltages from AC power. The power supply also switches on and off the AC power to the fuser heater bulb. The main power switch is hard-wired to the power supply.
High-Voltage Power Supply
The high-voltage power supply produces high voltage power for the charge and magnetic roller in the toner cartridge, the transfer roller, and the detack saw.
Basics Function of Main Components - 13
DC Controller Board
The DC controller board controls all printer operations. It has the following six major functions.
1. Communicates with the I/O board.
2. Communicates with the optional duplexer.
3. Receives information from the printer sensors and switches.
4. Controls the laser/scanner, fuser, and main motor.
5. Controls the printing process.
6. Distributes DC power from the power supply to other printer components.
Print Density Adjustment Knob
This knob adjusts the print density by changing the DC component of the developing bias voltage supplied by the high-voltage power supply. Turning this knob clockwise increases the print density. Turning this knob counterclockwise decreases the print density.
Print Density Adjustment Knob (User Accessible Side)
Basics Sensing System Locator (Printer Engine) - 14

Sensing System Locator (Printer Engine)

Cartridge Sensing and Laser/Scanner Interlock
Sensor: Cartridge Sensor Assembly (P/N 922-2811) Actuator: As the top cover closes, a tab on the toner cartridge presses an actuator in the cartridge sensor assembly.
A
(Fuser Assembly)
Full Stack Sensing (A)
B
Sensor: Part of Fuser Assembly Actuator: P/N 076-0653
Exit Sensing (B)
Sensor/Actuator: Part of Fuser
C
D
Assembly
(Transport Chute Assembly)
Registration Sensing (C)
Sensor/Actuator: P/N 076-0652
E
(Manual Feed Sensor Assembly)
Toner Sensing (D)
Toner Sensor Assembly (P/N 922-2799)
Manual Feed Paper-Present Sensing (E)
Sensor: P/N 922-2774 Acutator: P/N 922-2798
Fuser Cover Interlock
Actuator: As the fuser access cover (P/N 922-2757) closes, a tab on the cover presses the switch. Switch: P/N 922-2813
Top Cover Interlock
Actuator: As the top cover closes, the nylon tip of the laser/scanner actuator rod presses the switch. Switch: P/N 922-2812
Paper Size Sensing
Actuators: As cassette is inserted, size cams on cassette meet four size actuators on left cassette guide assembly (P/N 922-2773). Switches: Size actuators press microswitches on the cassette feeder board (P/N 922-2770).
Cassette Paper-Present Sensing
Actuator: P/N 922-2776 Sensor: P/N 922-2774
Basics Sensing System Locator (Duplexer) - 15

Sensing System Locator (Duplexer)

Full Stack Sensor
Full Stack Actuator (P/N 922-3038)
Duplex Paper-Pass Sensor (P/N 922-3037)
Duplexer Full
Stack Actuator
Duplexer Full
Stack Sensor
Upper Cover Interlock Switch
Duplexer Upper Cover
Duplexer Lower Cover
Paper-Pass
Sensor
Lower Cover Interlock Switch
Basics Wiring Diagram - 16

Wiring Diagram

Full Stack
Sensor
Offset Motor
P/J 192
P/J 196
P183
Fuser Cover
Interlock Switch
Exit
Sensor
Full
Stack
Sensor
Temp. Sensor
Heater Bulb
Thermostat
Thermal Fuse
Fuser Assembly
Paper-Pass Sensor
Duplex Motor
Interlock
Switches
P/J
P/J
193
198 P/J
197
195
P/J187P/J184P/J186
Duplexer Board
Duplexer
Main Motor
Cartridge-Present Sensor
Manual Feed
Sensor Assembly
Toner Sensor
Manual Feed Paper-
Present Sensor
Registration Sensor
Registration Clutch
Manual Feed Solenoid
P182
P/J
P/J
190
180
Power Inlet
Duplex Interface Board
P/J
942
P/J
142
Power Switch
P/J
Fan
Toner
Cartridge
DB CR DTS TR
HVPS
M
P/J221
P/J
134
P/J937
P/J
132
P/J135
P/J 122
P/J
124
Laser/Scanner
LD SOS MOT
P/J
112
P/J
P/J
15
151
P/J
16
P/J
P/J
171
17
P/J
22
P/J222
P/J922
P/J137
P/J 13
P/J131
P/J935
P/J
18
P/J
14
P/J11
P/J127 P/J121
Power Supply
P/J
113
P/J12
DC
Controller
Board
P/J21
P/J
114
P/J
20
P/J
23
P/J
19
P/J 31
Interlock Switch
Layout of sheet feeder is identical to cassette feeder board.
Sheet Feeder
P207
P202
Turn Clutch
P/J206P/J205
Cassette
Feeder
Board
P201
Actual
Board
Layout
Test Print
I/O Board
Top Cover
P/J
123
P/J 126
P/J 203
P12P17P14P18
P21 P11 P20
P/J412
Cassette Feed Paper-Present Sensor
P/J904
P/J204
Cassette Feed
Solenoid
P31
P23
DC
Controller
Board P16
P/J
P/J
411
421
P13 P22 P19 P15
Status
Panel
K
Service Source
Specifications
LaserWriter 8500
Specifications Engine - 1

Engine

Marking engine

Laser

Fuji Xerox P880 laser-xerographic
Type: Semiconductor laser diode Wavelength: 780 nanometers (nm) Output power: 5 milliwatts (mW) maximum
Specifications Controller - 2

Controller

Microprocessor

ROM
RAM

I/O processor

EEPROM

AMD Am29040 30/60-MHz RISC microprocessor
8 megabytes (MB) of ROM (including 136 fonts)
16 MB of RAM (expandable to 48 MB). See “RAM Memory” in the
Overview chapter for more information.
80C186 I/O processor
8 kilobytes (KB) parameter EEPROM
Specifications Ports - 3

Ports

General

LocalTalk port Parallel port
AAUI Ethernet port with three protocols: EtherTalk Novell NetWare IPX (PSERVER or RPRINTER) TCP/IP (lpd)
External Ethernet transceivers available for
thin coaxial (10BASE-2) thick coaxial (10BASE-5)
Ethernet twisted-pair cable (10BASE-T) can connect directly to
a hub Two-position communication switch All ports and protocols simultaneously active (but only one
Ethernet connector)
Specifications Imaging - 4

Imaging

Resolution

Grayscale imaging

PostScript

600 dots per inch (dpi) resolution 600 dpi FinePrint (edge enhancement for text and line art)
Enhanced 600 dpi grayscale imaging: Standard
85 lines/inch dithered halftone, 101 gray levels
106 lines/inch dithered halftone, 129 gray levels
141 lines/inch dithered halftone, 73 gray levels PhotoGrade (additional RAM may be required)
106 lines/inch halftone, 201 gray levels
141 lines/inch halftone, 257 gray levels
150 lines/inch halftone, 145 gray levels
PostScript Level 3
Specifications Imaging - 5

Printer fonts

Speed

One hundred thirty-six PostScript fonts are provided with the printer, including such fonts as Albertus, Antique Olive, Apple Chancery, Arial, ITC Avant Garde ®, Bondoni, ITC Bookman ®, Carta, Chicago, Clarendon, CooperBlack, Copperplate, Coronet, Courier, Eurostile, Geneva, GillSans, Goudy, Helvetica, Helvetica Black, Helvetica Compressed, Helvetica Narrow, Hoefler Text, Joanna, LetterGothic, Lubalin Graph, Marigold, Monaco, MonaLisa, New Century Schoolbook, New York, Optima, Oxford, Palatino ®, StempelGaramond, Symbol, Tekton, Times, Univers, Univers Condensed, WingDings, ITC Zapf Chancery ®, and ITC Zapf Dingbats ®.
Note
: Actual speed depends on the images printed.
One-sided: 20 pages per minute maximum using long-edge feed
(LEF) U.S. letter or A4-size paper. Duplex: 13 pages per minute maximum using long-edge feed U.S.
letter or A4-size paper. Envelopes—9.7 envelopes per minute maximum.
Specifications Life Expectancy - 6

Life Expectancy

Printer reliability (MTBF)

Toner cartridge life expectancy

Average number of impressions between failure is 180,000 pages. (In duplex mode, a single sheet is considered to be two impressions.)
Life expectancy is up to 14,000 pages when printing text documents with average page coverage (5% black). An example of a 5% black page coverage is a page consisting of double-spaced 14-point Courier type. Printing images and other graphics may shorten toner cartridge life expectancy.
Specifications Printing Materials - 7

Printing Materials

Paper types

Paper sizes and capacity

16- to 28-pound laser-quality bond (60 to 105 g/m 2 ); up to 36-pound (135 g/m 2 ) stock when fed manually through the multipurpose tray. Accepts most textured and colored stock. Accepts medium-weight photocopier transparencies and labels. Envelopes can be printed from the multipurpose tray or from the optional envelope feeder.
The paper used should not scorch, melt, transfer material, or release hazardous emissions when heated to 200° C (400° F) for
0.1 seconds.
The paper cassette holds 500 sheets of 20-pound (75 g/m 2 ) paper. The multipurpose tray can hold up to 150 sheets of standard U.S. letter paper, and other paper sizes from postcard up to U.S. legal. An optional 500-sheet feeder and cassette is
Specifications Printing Materials - 8
available. An envelope feeder that can automatically feed up to 50 envelopes is also available.
Standard 500-sheet cassette
Multipurpose tray
Paper Type Size U.S. Letter (LEF) 8.5" x 11" (215.9 mm x 279.4 mm) U.S. Letter Small (LEF) 8.5" x 11" (215.9 mm x 279.4 mm) Statement (LEF) 8.48" x 5.48" (215.9 mm x 139.7 mm) Executive (LEF) 10.5" x 7.25" (266.7 mm x 184.2 mm) A4 (LEF) 8.27" x 11.69" (210 mm x 297 mm) A4 Small (LEF) 8.27" x 11.69" (210 mm x 297 mm) A5 (LEF) 5.84" x 8.26" (148 mm x 210 mm) B5 (LEF) 7.17" x 10.12" (182 mm x 257 mm)
Paper Type Size U.S. Letter (LEF) 8.5" x 11" (215.9 mm x 279.4 mm) U.S. Letter Small (LEF) 8.5" x 11" (215.9 mm x 279.4 mm) A4 (LEF) 8.27" x 11.69" (210 mm x 297 mm) A4 Small (LEF) 8.27" x 11.69" (210 mm x 297 mm) A5 (LEF) 5.84" x 8.26" (148 mm x 210 mm) Executive (LEF) 10.5" x 7.25" (266.7 mm x 184.2 mm)
Specifications Printing Materials - 9
B5 (LEF) 7.17" x 10.12" (182 mm x 257 mm) Statement (LEF) 8.48" x 5.48" (215.9 mm x 139.7 mm) U.S. Legal (SEF) 8.5" x 14" (215.9 mm x 355.6 mm) U.S. Legal Small (SEF) 8.5" x 14" (215.9 mm x 355.6 mm) Tabloid (SEF) 11" x 17" (279.4 mm x 431.8 mm) A3 (SEF) 11.69" x 16.54" (297 mm x 420.2 mm) Large (SEF) 13" x 18" (330 mm x 457.2 mm) Large (SEF) 13" x 18.5" (330 mm x 470 mm) Large (SEF) 13" x 20" (330 mm x 508 mm) COM10 (SEF) 4.125" x 9.5" (104.8 mm x 241.3 mm) Monarch (SEF) 3.875" x 7.5" (98.4 mm x 190.5 mm) DL (SEF) 4.33" x 8.66" (110 mm x 220 mm) C5 (SEF) 6.38" x 9.02" (162 mm x 229 mm) Hagaki Postcard (SEF) 3.94" x 5.83" (100 mm x 148 mm)
Optional 500-sheet A3 cassette
Paper Type Size U.S. Letter (LEF) 8-1/2" x 11" (215.9 mm x 279.4 mm) U.S. Letter Small (LEF) 8-1/2" x 11" (215.9 mm x 279.4 mm) Statement (LEF) 8.48" x 5.48" (215.9 mm x 139.7 mm) Executive (LEF) 10.5" x 7.25" (266.7 mm x 184.2 mm)
Specifications Printing Materials - 10
A4 (LEF) 8.27" x 11.69" (210 mm x 297 mm) A4 Small (LEF) 8.27" x 11.69" (210 mm x 297 mm) A5 (LEF) 5.84" x 8.26" (148 mm x 210 mm) B5 (LEF) 7.17" x 10.12" (182 mm x 257 mm) U.S. Legal (SEF) 8.5" x 14" (215.9 mm x 355.6 mm) Tabloid (SEF) 11" x 17" (279.4 mm x 431.8 mm) A3 (SEF) 11.69" x 16.54" (297 mm x 420.2 mm) Large (SEF) 13" x 18" (330 mm x 457.2 mm) Large (SEF) 13" x 18.5" (330 mm x 470 mm)
Optional envelope sizes and weights
Optional duplex printing unit
Envelope Weight Size COM10 (SEF) 24 lb 4.125" x 9.5" (104.8 mm x 241.3 mm) Monarch (SEF) 24 lb 3.875" x 7.5" (98.4 mm x 190.5 mm) DL (SEF) 80 g/m 2 110 mm x 220 mm C5 (SEF) 90 g/m2 162 mm x 229 mm
Paper Type Size U.S. Letter (LEF) 8.5" x 11" (215.9 mm x 279.4 mm) U.S. Letter Small (LEF) 8.5" x 11" (215.9 mm x 279.4 mm) U.S. Legal (SEF) 8.5" x 14" (215.9 mm x 355.6 mm)
Specifications Printing Materials - 11
U.S. Legal Small (SEF) 8.5" x 14" (215.9 mm x 355.6 mm) A4 (LEF) 8.27" x 11.69" (210 mm x 297 mm) A4 Small (LEF) 8.27" x 11.69" (210 mm x 297 mm) B5 (LEF) 7.17" x 10.12" (182 mm x 257 mm) Ledger (SEF) 11" x 17" (279.4 mm x 431.8 mm) A3 (SEF) 11.69" x 16.54" (297 mm x 420.2 mm)
Specifications Dimensions - 12

Dimensions

Basic configuration (printer with A4 cassette)
Height: 16.2 in. (41.1 cm) Width: 23.2 in. (58.9 cm) Depth: 17.9 in. (45.5 cm)
Additional dimension when adding the duplexer Height: 2.9 in. (7.4 cm) Depth: 3.0 in. (7.6 cm)
Additional dimension when adding the sheet feeder and A3 universal cassette Height: 5.2 in. (13.2 cm) Depth: 5.9 in. (15.0 cm)
Additional dimension when adding the sheet feeder and letter/A4 universal cassette Height: 5.2 in. (13.2 cm)
Specifications Dimensions - 13

Space requirements

Weight

About 6 in.
or 15 cm
Exhaust Vent
About 7 in. or 18 cm
About 1 in. or 2.5 cm
About 17 in.
or 43 cm
Approximately 30 lb. (14 kg)
Note: Vertical clearance is about 14 in. or 36 cm
Specifications Environmental - 14

Environmental

Operating

Storage (toner cartridge)

Storage (printer)

Temperature: 41° to 95° F (5° to 35° C) Humidity: 15 to 85 percent relative humidity noncondensing Altitude: 0 to 8200 feet (0 to 2500 meters)
Note
: There is a varistor VR53 is in the upper left corner of the high-voltage power supply. Counter-clockwise adjustment of this varistor lowers the toner threshold and increases the maximum operating altitude.
Temperature: 32° to 95° F (0° to 35° C) Humidity: 15 to 80 percent relative humidity noncondensing
Temperature: 32° to 95° F (0° to 35° C) Humidity: 15 to 80 percent relative humidity noncondensing
About 13 in. or 32 cm
Specifications Environmental - 15

Voltage requirements

Power consumption

U.S.
90 to 132 VAC, 47 to 63 Hz 100 to 120 nominal voltage, 50 to 60 nominal Hz
Europe and Australia
198 to 264 VAC, 47 to 63 Hz 220 to 240 nominal voltage, 50 to 60 nominal Hz
Important
specific: the power supply, the fuser assembly, the transport chute assembly, and the DC controller board. Refer to the Parts chapter for more information.
Energy-saving mode
26 watts (W)
Standby average
100/120 volts (V), approximately 125 W 220/240 V, approximately 120 W
: There are four parts in the printer that are voltage-
Specifications Environmental - 16
Operating average
110/120 V, approximately 390 W 220/240 V, approximately 370 W
Maximum power consumption
120 V, approximately 840 W, 6.3 amperes (A) 240 V, approximately 860 W, 3.2 A
K
Service Source

T ak e Apart

LaserWriter 8500
Take Apart General - 1
General
Before you begin, perform the following procedures:
• Switch off power and unplug the printer
• Remove duplexer and/or sheet feeder (if applicable)
• Remove cassette
• Remove toner cartridge
Before working on any printed circuit board, ground yourself and your equipment to an earth or building ground. Use a grounded conductive workbench mat and grounding wriststrap, and ground your equipment to the mat.
Take Apart Fuser Access Cover - 2
Fuser Access

Fuser Access Cover

Cover
No preliminary steps are required before you begin this procedure.
Take Apart Fuser Access Cover - 3
1 Open the fuser access
cover and shift it left­ward to release its right hinge.
Fuser Cap
2 Free the left hinge and
remove the fuser access cover from the printer.
Note
: The fuser cap is the part that you remove before installing a duplexer. The cap is a part of the fuser
Fuser Access
Cover
access cover (P/N 922-
2757).
Take Apart Left Top Cover - 4
= Location of Detent

Left Top Cover

Left Top Cover
Before you begin, remove the fuser access cover.
Note
: The left top cover is held to the printer by two screws, a detent (on the cover’s bottom edge, near where the three covers abut one another), and the status panel cable.
Take Apart Left Top Cover - 5
Detent
Status
Panel
Cable
Left Top Cover
Screw
Screw
Top Cover
Status Panel
Left Top Cover
(On Its Side)
1 Open the manual feed
tray and the top cover.
2 Remove the two screws
securing the left top cover to the printer frame (one along the rear and one inside the manual feed compart­ment).
3 Pull out slightly on the
left top cover to release the detent and rest the cover on its side atop the chassis.
4 Disconnect the status
panel cable and remove the cover.
Take Apart Left Top Cover - 6
Note
: The status panel is not part of the left top cover, but is
available separately as P/N 922-2767.
Temporary Support
For Top Cover
Caution
: With the left or right top covers removed, fingers are no longer fully protected from the closure of the top cover. Whenever possible, keep the top cover closed.
If you must work with the top cover open, however, first make sure that it is all the way up in the latched position. In addition, place a temporary support (a piece of folded cardboard, cloth, newspaper, etc.) in the space beneath the side flange of the top cover.
Take Apart Left Cover Assembly - 7

Left Cover Assembly

Left Cover
Assembly
No preliminary steps are required before you begin this procedure.
Take Apart Left Cover Assembly - 8
1 Loosen the two knurled
captive screws securing the left cover assembly.
2 Slide the cover to the left
to free its front edge and
Left Cover
Assembly
Screw
remove the cover from the printer.
Take Apart Front Left Cover - 9

Front Left Cover

Before you begin, remove the following:
• Left top cover
• Left cover assembly
Front Left Cover
Take Apart Front Left Cover - 10
1 Release the two tabs at
the top of the front left cover and remove the cover from the printer frame.
Front Left Cover
Take Apart Left Lower Cover - 11

Left Lower Cover

Before you begin, remove the left cover assembly.
Left Lower Cover
Take Apart Left Lower Cover - 12
1 Remove the two screws
securing the left lower cover and remove the cover from the printer frame.
Left Lower Cover
Take Apart Right Top Cover - 13

Right Top Cover

Before you begin, remove
Right Top Cover
the fuser access cover.
Take Apart Right Top Cover - 14
1 Open the manual feed
Right Top Cover
tray and the top cover.
2 Remove the two screws
securing the right top cover to the printer frame (one along the rear and one inside the manual feed compart­ment).
3 Lift the cover straight
up and off the printer.
Take Apart Right Top Cover - 15
Temporary Support
For Top Cover
Caution
: With the left or right top covers removed, fingers are no longer fully protected from the closure of the top cover. Whenever possible, keep the top cover closed.
If you must work with the top cover open, however, first make sure that it is all the way up in the latched position. In addition, place a temporary support (a piece of folded cardboard, cloth, newspaper, etc.) in the space beneath the side flange of the top cover.
Take Apart Right Cover - 16

Right Cover

Before you begin, remove the following:
• Fuser access cover
• Right top cover
Right Cover
Take Apart Right Cover - 17
1 Remove the five screws
that secure the right cover to the printer (two at the bottom, two along the rear edge, and one at the top).
2 Release the detent edge of
Detent Edge
the cover (where the cover wraps around to meet the cassette guide) and remove the right cover from the printer.
Right Cover
Take Apart Exit Cover - 18

Exit Cover

Exit Cover
Before you begin, remove the following:
• Fuser access cover
• Left top cover
• Right top cover
Take Apart Exit Cover - 19
1 Close the top cover.
Exit Cover
2 Remove the two screws
securing the exit cover (one low at the right and one angled at the left).
Full Stack Actuator
Caution
: In the following step, make sure to hold the full-stack actuator clear while you remove the cover. The actuator is exposed and very susceptible to damage.
3 Tilt the exit cover
forward to clear the actuator and lift the cover from the printer.
Take Apart Top Cover - 20

Top Cover

Top Cover
Before you begin, remove the following:
• Fuser access cover
• Left top cover
• Right top cover
• Exit cover
1 Open the top cover
housing.
Caution
placed a temporary support underneath the top cover as described in the left top cover and right top cover topics.
: Make sure you have
Take Apart Top Cover - 21
2 Remove the two screws
Top Cover
securing the top cover to the housing (one on the left and one on the right outer face of the cover).
3 Remove the temporary
support and close the top cover.
4 Slide cover slightly
forward and remove the cover from the frame.
Take Apart Front Cover - 22

Front Cover

Before you begin, remove the following:
• Fuser access cover
• Left top cover
• Left cover assembly
• Front left cover
• Right top cover
• Right cover
Note
: The manual feed cover assembly and the front cover come off together.
Front CoverManual Feed
Cover Assembly
Take Apart Front Cover - 23
1 Remove the two screws
securing the front cover to the chassis.
2 Lift out the manual feed
cover assembly together with the front cover.
Note
: Perform step 3 only if you are replacing a damaged front cover or manual feed cover.
3 Flex one arm of the front
cover to release the hinge and separate the front cover from the manual feed cover.
Front Cover
Manual Feed Cover Assembly
Take Apart Turn-In Chute - 24

Turn-In Chute

No preliminary steps are required before you begin this procedure.
Turn-In Chute
Turn Chute Cover
1 Hold open the turn chute
cover.
2 Flex the left side arm of
the turn-in chute and remove its hinge hole from the boss on the left cassette guide assembly.
3 Remove the turn-in
chute from the cassette guide.
Boss
Take Apart Turn Chute Cover - 25

Turn Chute Cover

Before you begin, remove the turn-in chute.
1 Hold the turn chute
cover half open.
2 Using needle-nosed
pliers, remove the two turn chute springs that are installed between the turn chute cover and the left and right cassette
Turn Chute Cover
guide assemblies.
3 Hold the turn chute
cover completely open and slide to the left.
Take Apart Turn Chute Cover - 26
4 Lift the rear of the
printer and pull down the right side of the turn chute cover.
5 Slide the turn chute
cover to the right and remove it from the printer.
Turn Chute Cover
Take Apart Fuser Assembly - 27

Fuser Assembly

Screw
Screw
Fuser Assembly
Screw
Screw
Before you begin, remove the fuser access cover.
Caution
assembly cool before performing this procedure.
1 Loosen the four captive
: Let the fuser
screws securing the fuser assembly to the printer.
Take Apart Fuser Assembly - 28
2 Grip the fuser assembly
Handle
Handle
by the two small handles at each end and lift the fuser from the printer.
Take Apart I/O Board - 29

I/O Board

Before you begin, remove the following:
• Fuser access cover
• Left top cover
• Left cover assembly
• Front left cover
1 Make a note of the
position of the reset button on the I/O bracket.
2 Disconnect the two
cables at the right side the board.
Reset
Button
Cables
I/O Board
I/O Board with Shield
Take Apart I/O Board - 30
7654
3 Remove the eleven
silver-colored screws that secure the I/O
11
2
3
8
shield to the chassis (1­2 on the left, 3 below the fan, 4-7 at the top, 8, 9, and 11 on the right, and 10 at the bottom.)
4 Pull the controller board
with the intact shield from the printer.
Note
: There may be some
1
9
resistance from the receptacle connector on the blind side of the board (near the top, just
10
left of center).
Take Apart I/O Board - 31
Note
: Peform the following steps only if you are replac-
I/O Bracket
I/O Board Screw
(Step 5)
ing a defective I/O board.
5 Remove the screw at the
bottom left corner of the I/O board.
6 Remove the two screws
and the six small I/O connector screws that secure the I/O bracket to the shield.
7 Remove the I/O bracket.
Screw
Connector
Screws
Screw
8 Remove the four
remaining screws (step five removed the fifth) that secure the I/O board
Take Apart I/O Board - 32
to the shield
Receptacle Connector
Backside of I/O Shield
Metal Tabs
9 Remove the board, being
careful to elevate the receptacle on the rear to clear the plate.
Replacement Notes
:
• When replacing the I/O
bracket, make sure that the three metal tabs slide in the cutouts in the shield.
• Check the position of the
reset button on the I/O bracket, and restore the setting if you have accidently changed it during this procedure.
Take Apart Cassette Feeder Board - 33

Cassette Feeder Board

Before you begin, remove the following:
• Left top cover
• Left cover assembly
• Front left cover
• Left lower cover
• I/O board
Cassette Feeder Board
Take Apart Cassette Feeder Board - 34
Cassette Feeder Board
Screw
Cable
Screw
Screw
Screw
1 Disconnect the cable
going into the left side of the board.
2 Remove the four screws
securing the cassette feeder board.
Note
: To loosen the bottom left screw, insert the screwdriver through the opening in the printer frame.
Take Apart Cassette Feeder Board - 35
3 Lift the board away
Disconnect Cables
from the printer and disconnect the two remaining cables.
4 Remove the cassette
feeder board from the printer.
Take Apart Duplex Interface Board - 36

Duplex Interface Board

Before you begin, remove the following:
• Fuser access cover
• Left top cover
• Left cover assembly
• Front left cover
• I/O board
Duplex Interface Board
Take Apart Duplex Interface Board - 37
Screws
Cable
Duplex Interface Board
1 Disconnect the cable on
the rear face of the board.
2 Remove the two screws
that secure the connector end of the board to the chassis frame.
Take Apart Duplex Interface Board - 38
3 Pull out on the right end
of the board to free the receptacle connector on the opposite side.
4 Slide the board to the
right and remove it from the printer.
Take Apart DC Controller Board - 39

DC Controller Board

DC Controller Board
Before you begin, remove the following:
• Fuser access cover
• Left top cover
• Left cover assembly
• Front left cover
• I/O board
• Duplex interface board
Take Apart DC Controller Board - 40
ScrewScrew
Screw Screw
Screw Location for Board-Only Removal
1 Disconnect all the cables
going into the board.
Note
: If you are replacing the DC controller board, perform step 2 and you are done. If all you need is access to a deeper part, go to step 3.
2 Remove the four screws
that secure the control­ler board to the chassis (one at each corner of the board) and remove the board from the printer.
Take Apart DC Controller Board - 41
Note
ScrewScrew
: The following steps remove the DC controller board holder along with the board.
3 Remove the cables from
the cable clamps.
4 Remove the four screws
that secure the control­ler board holder to the chassis (two along the top flange, one to the right of the density dial, and one below the left corner of the board).
Screw Screw
Screw Location for Board and Holder Removal
Take Apart DC Controller Board - 42
5 Remove the controller
board and holder from the printer.
Removing Board and Holder
Take Apart Fan - 43
Fan
Fan
Before you begin, remove the following:
• Fuser access cover
• Left top cover
• Left cover assembly
• Front left cover
• I/O board
1 Remove the two lower
screws that secure the fan to the chassis.
Take Apart Fan - 44
Ferrite Core
2 Disconnect the fan cable
from P/J122 on the power supply.
3 Open the cable clamp
(near the density dial) and the ferrite core (near the fan), pull the fan cable free, and remove the fan from the printer.
P/J122Cable Clamp
Take Apart Power Supply - 45

Power Supply

Before you begin, remove the following:
• Fuser access cover
• Left top cover
• Left cover assembly
• Front left cover
• Left lower cover
• I/O board
Note
: The main power receptacle and switch (also known as the power inlet) is hard-wired to the power supply.
Power Supply Power Inlet
Take Apart Power Supply - 46
1 Remove the screw
securing the grounding wire to the chassis.
2 Remove the three screws
securing the power inlet holder and lift the holder up from the chassis.
3 Remove the power cable
from the two clamps.
Grounding Screw
Power Inlet Holder
Screws
Screw
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