Samsung ML-7000P, ML-7000N Service manual

ML-7000 Series

1. Precautions

2. Reference Information

3. Product Information

4. Disassembly

5. Trouble Shooting

6. Exploded Views & Parts List

7. Block Diagrams

8. PCB Diagrams

9. Port Thru
(Network Printer Card)

ML-7000P
ML-7000N
QwikLaser 7000
QwikLaser 7000P
QwikLaser 7000N

SERVICE

Manual

Laser printer Contents

ELECTRONICS

© Samsung Electronics Co., Ltd. Sep. 1998

Printed in Korea
P/N. JC68-00034A Rev 1.00

List of Contents

1. Precautions

1-1 Safety Precautions
1-2 Laser Safety Statement

2. Reference Information

2-1 Abbreviations and Acronyms
2-2 Diagnostic Control Unit

3. Product Information

4. Disassembly

4-1 Front View
4-2 Rear View
4-3 Cabinet disassembly
4-4 Video Controller Board & Joint Board
4-5 Fuser Ass’y
4-6 Bracket Motor Ass’y & Cover Open

Switch Unit

6. Exploded Views & Parts List

6-1 Cover Ass’y
6-2 Frame Ass’y
6-3 Cassette Ass’y
6-4 MP Tray Ass’y
6-5 Pick Up Ass’y
6-6 Fuser Ass’y
6-7 Shield Ass’y
6-8 Bracket Duplex Ass’y
6-9 Bracket Motor Ass’y
6-10 Frame SCF Ass’y
6-11 Cassette SCF Ass’y
6-12 Miscellaneous Items

7. Block Diagrams

7-1 Wiring Diagrams
7-2 Engine Controller
7-3 Video Controller

4-7 Pickup Ass’y
4-8 Laser Scanner Unit
4-9 Multi Purpose Tray
4-10 Control Panel
4-11 Engine Controller Board
4-12 SMPS & Bracket Duplex Ass’y
4-13 Transfer Roller Ass’y

5. Troubleshooting

5-1 Print Quality
5-2 HVPS OUTPUT Spec
5-3 Malfunction
5-4 Connector Pin Assignment
5-5 Trouble shooting of Video Controller.

8. PCB Diagrams

8-1 Engine Controller Board & Joint Board
8-2 Cassette Sensor Board
8-3 Video Contoller Board
8-4 Panel & LCD Board
8-5 PTL (Pre Transfer Lamp) Board
8-6 SCF (Second Cassette Feeder) Board
8-7 InfraRed Adaptor Board
8-8 Flash SIMM Board
8-9 Postscript Board
8-10 Local Talk & Serial Board

9. Port Thru (Network Printer Cord) :
Option

1. Precautions

1-1 Safety precautions

Read each caution carefully

1. Do not use the pinter near water or when exposed to inclement weather.

2. Do not place this printer on an unstable cart, stand or table, the product may fall, causing
serious damage to the product.

3. Slots and openings on the cabinet are provided for ventilation. To ensure reliable operation
and to protect the printer from overheation, do not block or cover any of these openings. Do
not place the printer in an enclosure unless the enclosure providesadequate ventilation.

4. Never push any kind of objects into the printer through the cabinet ventilaition slots as they
may touch dangerous hihg voltage points, create short circuits, cause a fire, or produce an
electrical shock. Never spill any kind of liquid on the printer.

5. Do not place the printer in a lacation where someone may trip on the cord.

6. Select a work surface that is lartge enough to hold the printer.

7. Operate this printer using the power source (110V, 220V, etc) indicated on the marking label.
If you are not sure of the type of power source available, consult your dealer or local power
company.

8. If you need to use an extension power cord with this printer, make sure that is uses a three­wire grounded cord and that the total ampere ratings for all of the products using the
extension, do not exceed the extension cord ampere ration.

9. Do not allow anything to rest on th power cord or data communications cable.

10. Unplug this printer from the wall outlet before cleaning. Do not use liquid cleaners or aerosol
sprays. Use a damp cloth for cleaning.

11. Do not touch the surface of the photo-sensitive drum as marks ro scratches may impair print
quality.

12. Do not expose the drum unit to direct light for prolonged periods.

13. Use only standard papers, OHP films and approved envelopes.

1-2 Laser Safety Statement

Caution: Never operate and service the printer with the protective cover removed from Laser Scanner

Assembly. The reflective beam, although invisible, can damage your eyes

The printer is certified in the U.S to conform to the requirement of DHHS 21CFR Subchapter J for Class I(1) laser
product, and elsewhere is certified as a class I laser product conforming to the requirement of IEC 825.

Class I laser product are not considered to be hazardous. The laser system and printer are designed so there is never
any human assess to laser radiation above a Class I level during normal operation, user maintenance, or prescribed
service condition

CAUTION - INVISIBLE LASER RADIATION WHEN THIS COVER OPEN.

DO NOT OPEN COVER

VORSICHT- UNSICHTBARE SASERSTRAHLUNG, WENN ABDECKUNG GEÖFFNET.

ATTENTION - RAYONNEMENT LASER INVISIBLE EN CAS D’OUVERTURE, EXPOSITION DANGEREUSE AU
ATTENZIONE - RADIAZIONE LASER INVISIBLE IN CASO DI APETURA, EVITARE L’ESPOSIZIONE AL FASCIO.

PRECAUCION - RADIACION LASER IVISIBLE CUANDO SE ABRE, EVITAR EXPONERSE ALRAYO.
ADVARSEL - USTNLIG LASERSTRÄLNING VED ÄBNING, NÄR SIKKERHEDSBRYDERE ER UDE AF

ADVARSEL - USYNLIG LASERSTRÄLNING NÄR DEKSEL ÄPNES, STIRR IKKE INN I STRÄLEN, UNNGÄ
VARNING -OSYNLIG LASERSTRÄLNING NÄR DENNA DELÄR ÖPPNADOCH SPÄRREN ÄR URKOPPLAD,
VARO! - AVATTAESSA JA SUOJALUKITUS OHITEETTAESSA OLET ALTTINA NÄKYMÄTTÖMÄLLE

¡÷ ¿« - ¿Ãµ§∞≥∏¶ø≠∏È∑π¿Ã¡Æ±§ø°≥Î√‚µ…ºˆ¿÷¿∏π«∑Œ¡÷¿««œΩ Ω√ø¿.

NICHT DEM STRAHL AUSSETZEN.

FAISCEAU.

FUNKTION, UNDGÄ UDSAETTELSE FOR STRÄLNING.
EKSPONERING FOR STRALEN.
BETRAKTA EJ STRÄLEN, STRÄLEN ÄR FARLIG.
LASER SÄTELYLLE ÄLÄ KATSO SÄTEESEEN.

LSU caution label is located on the LSU top side

CLASS 1 LASER PRODUCT
LASER KLASSE 1
LUOKAN 1 LASERLAITE
APPAREIL A LASER DE CLASSE 1
TO IEC 825

2. Reference Information

2-1 Abbreviations and Acronyms

Tables 2-1 and 2-2 List abbreviations and acronyms which may be found in this sevice manual.

Table 2-1. Abbreviations

Abbv Definition Abbv Definition

amps amperes lb pound(s)

lin linearity

ass’y assembly lock bus lock

badac bad assess mm millimeter(s)

neg negative

bps bits per second od open drain

clk clock OSC oscillator

cm centimeter(s) OUT output
CON connector PIC picture
GND ground pos positive or position

HLDA hold acknowledge pot potential

HLDAR hold acknowledge received psynrq page synchronizaton request

HLDR hold request pwr power

HOR horizontal qty quantity

in inch(es) or input sw switch

INTA interrupt Acknowledge sync synchronous or

synchronization

INT Interrupt tach tachometer

INTR Interrupt request Vcc collector supply valtage(dc)

I/O Input and Output vert vertical

mpx multiplex Vp-p peak-to-peak voltage

VR variable resistor

Table 2-2. Acronyms

Acronym Definition Acronym Definition

ABL Automatic Blanking Limiter IDE Intelligent Drive electronics or

Imbedded Drive Electronics

ACC Automatic Color Control IF Intermediate Frequency

ADC Analog to Digital Converter IPM Images Per Minute

ADS Address/Data Status ISA Industry Standard Architecture

ALE Address-Latch Enable KBC Keyboard Controller

ASCII American Standard Code for LAD Local Address/Data Bus

Information interchange

BIOS Basic Input/Output System LCD Liquid Crystal Display

BPF Band Pass Second LED Light Emitting Diode
BPS Bits Per Second MCA Micro Channel Architecture

CCFT Cold Cathode Fluorescent Tube MDA Monochrome Display Adapter

CGA Color Graphics Adapter NC No Connection

CMOS Complementary Metal Oxide NF Noise Fiqure or Noise Factor

Semiconductor
CPU Central Processing Unit PA Power Amplifier
CRT Cathode Ray Tube PBA Printed Board Assembly
CRU Customer Replacement Unit

DMA Direct Memory Access or PBM Primary Bus master

Dynamic Memory Address

DMAC Direct Memory Access PCB Printd Circuit Board

Controller

DVM Digital Voltmeter PCMCIA Personal Computer Memory

Card International Association

EEPROM Electronically Erasable Pro- PLCC Plastic Leaded Chip Carrier

grammable read Only Memory
EGA Enhanced Graphics Adapter PMS Power Management System

EISA Extended Industry Standard POST Power On Self Test

Architecture

ESDI Enhanced Small Device PPM Pages Per Minute

Interface
FDC Floppy Disk Controller PQFP Plastic Quad Flat Package
FDD Floppy Disk Drive QFP Quad Flat Package

FL Fluorescent Light(Lamp) RAM Random Access Memory

HDD Hard Disk Drive ROM Read Only Memory

HPF High Pass Filter RTC Real-Time Clock

SCSI Small Computer Systems SBM Secondary Bus Master

Interface

SIO Serial Input/Output Controller TSTN Triple Super Twisted Nematic

SOP Small Outline Package UHF Ultrahigh Frequency

SSOP Shrink Small Outline Package VCO Voltage Controlled Oscillator

STN Super Twisted Nematic VESA Video Electronics Standard

Association

SCC Serial Communications VGA Video Graphics Array

Controller

TFT Thin Film Transistor VHF Very High Frequency

TS Tri-State XO Crystal Oscillator

TSOP Thin Small Outline Package

2-2. Diagnostic Control Unit

2-2-1. Abstract

The diagnostic Control Unit(DCU) is useful for troubleshooting the Laser beam printer ML Series engines,
and for checking printer status.
The DCU can be used in common for ML series, but each model has several different code description.
Refer to the code description for ML-7000 in next page.

< Fig 1-1. ML-80 DCU >

2-2-2. List of code description

Code Description

1. DIAGNOSTIC CODE 2.STATUS CODE

00 MAIN MOTOR OPERATING 78 SYSTEM ERROR
01 MAIN HIGH VOLT ON / OFF TEST 00 Ready to print from LEGAL paper tray
02 THV (- ) ON / OFF TEST 01 Ready to print form LETTER paper tray
03 THV (+) ON / OFF TEST 02 Ready to print form A4 paper tray
04 DEV, SUPPLY ON / OFF TEST 03 Ready to print form EXEC paper tray
05 LSU OPERATING TEST 04 Ready to print from B5 paper tray
06 PICK UP CLUTCH ON 05 Ready to print from FOLIO paper tray
07 PE, DS1, DS2 SENSOR TEST 20 PRINT START (1st CASSETTE)
08 MP, EXIT, FEED SENSOR TEST 21 PRINT START (MULTI PURPOSE)
09 TOP & REAR COVER OPEN, 22 PRINT START (2’nd CASSETTE)

OUT BIN SENSOR TEST 23 PRINT START (DUPLEX)
10 FUSER TEST 50 PAPER OUT
11 HOT BURN TEST 60 OPEN FUSER ERROR
12 DUPLEX CLUTCH TEST 62 LOW HEATER ERROR
13 MULTI PURPOSE CLUTCH TEST 68 OVER HESTER ERROR
14 THERMISTER 2 TEST 61 WARM-UP
15 PAPER SIZE SENSOR TEST 64 COVER OPEN ERROR

69 SLEEP MODE
70 NO PAPER or CASSETTE
71 PAPER JAM “0”
72 PAPER JAM “1”
73 PAPER JAM “2”
74 DUPLEX JAM “1”
75 DUPLEX JAM “2”
76 OUT BIN FULL
95 LSU NOT READY

2-2-3. The Diagnostic Control Unit (DCU) Operating Guide

¶°Display the engine status and error status code. Refer to List of Code Description.

2) Self-Test mode.

¶°When the engine is ready, this button starts printing a streak pattern.

3) Green mode

¶°Transfer high Voltage adjustment mode

With the power off, hold down the Self-Test button and turn on the pinter. Continue holding down the button
for 5 seconds to start Green mode.

4) Diagnostic Control mode.

¶°With the power off, hold down the 3 button (up/down, shift, stop/enter) and turn on the printer

Continue holding down the button for 5 seconds to start Diagnostic Control mode on the engine.

¶°The DCU has three diagnostic control buttons.

UP : Steps the function of the other two buttons:
SHIFT : Controls the function of the other two buttons:

SHIFT+UP means step down and SHIFT+START means stop.

START : Stasrts or stops the current diagnostic test.

Code Key Operation LED Display

00 ENTER Run Main Motor Lighten ON LED

SHIFT+STOP Stop Main Motor Lighten OFF LED
UP Increment DCU Code No. (01, MHV)
SHIFT+DOWN Decrement DCU code No. (13, MP)

01 ENTER MHV ON Lighten ON LED

SHIFT+STOP MHV OFF Lighten OFF LED
UP Increment DCU Code No. (02, THV Negative)
SHIFT+DOWN Decrement DCU code No. (00, Main Motor)

02 ENTER THV Negative ON Lighten ON LED

SHIFT+STOP THV Negative OFF Lighten OFF LED
UP Increment DCU Code No. (03, THV)
SHIFT+DOWN Decrement DCU code No. (02, MHV)

03 ENTER THV ON Lighten ON LED

SHIFT+STOP THV OFF Lighten OFF LED
UP Increment DCU Code No. (04, Dev)
SHIFT+DOWN Decrement DCU code No. (02, THV Negative)

04 ENTER DEV, SUPPLY ON Lighten ON LED

SHIFT+STOP DEV, SUPPLY ON Lighten OFF LED
UP Increment DCU Code No. (05, LSU)
SHIFT+DOWN Decrement DCU code No. (03, THV)

05 ENTER LSU Motor On Lighten 3rd LED

UP LSU Leady and LD On Lighten 1, 2nd LED
SHIFT+STOP LSU Motor OFF
UP Increment DCU Code No. (06, Pickup Clutch)
SHIFT+DOWN Decrement DCU code No. (04, Dev)

The DCU has functions as follows:

1) Engine Status and Error Code Display mode

Code Key Operation LED Display

ßZ15°…1st LED ON
No Action 15°…¶ZTemperature ¶Z30°…2nd LED ON
No Action Temperature ß[30°…3nd LED ON
No Action Thermister 2 Open All LED ON
No Action Thermister 2 Short All LED OFF
UP Increment DCU code No.

(15, Cassette sensor TEST)

SHIFT + DOWN Decrement DCU Code No. (13, MP Clutch TEST)

15 No Action Cassette Sensor 1 ON/OFF 1st LED ON/OFF

No Action Cassette Sensor 2 ON/OFF 2nd LED ON/OFF
No Action Cassette Sensor 3 ON/OFF 3nd LED ON/OFF
UP Increment DCU Code No. (00, Main Motor)
SHIFT + DOWN Decrement DCU Code No. (14, Thermister 2 Test)

06 ENTER Pickup Clutch ON Lighten ON LED

SHIFT+STOP Pickup Clutch OFF Lighten OFF LED
UP Increment DCU Code No. (07, Sensor TEST)
SHIFT+DOWN Decrement DCU code No. (06, Pickup Clutch)

07 No Action Paper Empty Sensor ON/OFF 1st LED ON/OFF

No Action Duplex 1 Sensor ON/OFF 2nd LED ON/OFF
No Action Duplex 2 Sensor ON/OFF 3rd LED ON/OFF
UP Increment DCU Code No. (08, Sensor TEST)
SHIFT+DOWN Decrement DCU Code No. (06, Pickup Clutch)

08 No Action Multi Purpose Sensor ON/OFF 1st LED ON/OFF

No Action Exit Sensor ON/OFF 2nd LED ON/OFF
No Action Feed Sensor ON/OFF 3rd LED ON/OFF
UP Increment DCU Code No. (09, Sensor TEST)
SHIFT+DOWN Decrement DCU Code No. (07, Sensor TEST)

09 No Action Cover Open Sensor ON/OFF 1st LED ON/OFF

No Action Cover Open Sensor ON/OFF 2nd LED ON/OFF
No Action Out Bin Sensor ON/OFF 3rd LED ON/OFF
UP Increment DCU Code No. (10, Fuser TEST)
SHIFT+DOWN Decrement DCU Code No. (08, Sensor Clutch)

10 ENTER Fuser ON Lighten ON LED

SHIFT+STOP Fuser OFF Lighten OFF LED
UP Increment DCU Code No. (04, Dev)
SHIFT+DOWN Decrement DCU code No. (02, THV Negative)

12 ENTER Duplex Clutch ON Lighten ON LED

SHIFT+STOP Duplex Clutch OFF Lighten OFF LED
UP Increment DCU Code No. (13, MP Cluth)
SHIFT+DOWN Decrement DCU code No. (11, Self-Test)

13 ENTER Multi Purpose Clutch ON Lighten ON LED

SHIFT+STOP Multi Purpose Clutch OFF Lighten OFF LED
UP Increment DCU Code No. (14,Thermister 2 Test)
SHIFT+DOWN Decrement DCU code No. (12, Duplex Clutch)

14 No Action Temperature

3. Product Information

°ø442 °ø301mm

Weight Less than 16.5Kg (36.4lb) not packaged

Power Consumption 340W Avg/ 34W Sleep

Printing : °¬50dB

Noise Level Standby : °¬36dB

Sleep : Background noise Blow Fan off
Input Capacity 500 sheets Universal
Optional Input 500 sheets (40 envelopes)

Output Capacity 250 sheets Facedown No faceup mode

MP Tray 100 sheets (10 envelopes)

Envelop Feeder

supported by Multi-Purpose tray, optional cassette

Paper °§Cassette : A4, LTR, FO, LEG, EXE, ISO B5

Handling Type of Media °§MP Tray : Legal~A6, OHP, LABEL

COM-10, MON, DL, C5, C6

°§Optional Cassette : A4, LTR, FO, LEG

COM-10, MONARCH, DL, C5

Duplexing Paper : A4, LTR, FO, LEG

Paper Sensor Yes

CRU type Single cartridge Replacement
CRU Life 8,000 pages at 5% coverage

Imaging Cleaning System Mechanical Cleaning

Catridge Charging/Transfer Contact Charging & Transfer

Toner Sensor Yes

Toner saving Yes

°§8°ø2 LCD

Control Panel °§LCD Display angle adjusting

Others °§Backlighting

Paper Level Indicator Visible Mechanism

Power Switch Front & Left side, Push botton

Engine Specifiation

Item Descriptions Remarks

Speed 17 PPM Letter

Resolution 600 DPI +RET

Imaging Eletrophotography

Toning/Fusing Non-mag monocomponent/contact

WarmUp time Less than 60 secs N/N condition

FPOT Less than 13 secs standby mode

Engine Duty Cycle Maximum 50,000 pages per month

Size(WDH) 427

Controller Specification

°§Default : PCL6

°§Option : Postscript Level 2

°§4MB Standard

°§Max up to 68MB

°§Speed : 60nS

°ÿDRAM Module’s Features

°§Refresh Time : 2048 Cycles/32mS

Memory

°§Fast Page Mode with Extended data out

°§CAS-before-RAS refresh capability
°§TTL compatible inputs and outputs
°§Single +5V °æ10% power supply
°§2, 4MB Flash memory option
°§Postscript : 12MB Standart P.S Simm Module
°§IEEE 1284 B type

Option :

Interface Serial RS 232C

Controller InfraRed Adaptor connector

Local Talk,
Internal Network

AIS/AES Y/Y

Font 35 Intellifont, 10 True Type, 1Bit Map

°§Ethernet TCP/IP, SPX/IPX

Port Thru

°§10 base T Apple Talk,

(Network Printer Card)

°§SNMP in MIB NetBEUI/NetBios
°§TCP/IP
°§Netware, Windows, OS/2, Unix, Mac

Device Driver PCL : Windows 3.1/95/NT, DOS

Item Descriptions Remarks

CPU Power PC, 100MHZ

Emulation

4. Disassembly

°‹

°‹

°‹

°‹

°‹

°‹

°‹

°‹

°‹

Controller

Cassette

Power Inlet

4-1 Front View

Control Panel

Cover Open

Power Switch

Cover Tray

Cover Front

Paper Level Indicator

4-2 Rear View

Cover Rear

4-3 Cabinet Disassembly

°‹

°‹

Screw

Cover Rear

Cover Right

Screw

Hook

4-3-1. Cover Right

Remove the screws and open the
Cover Rear.

In order to remove the Cover Right.
Please see the hook which locks
the cabinet to the frame, right hand
should first grab the hook and pull it
out for releasing the hook from the
frame.

The left hand should slide the
Cover Right to the backward.

4-3-2. Cover Left

Hook

Hook

Screw

Remove screw and open the Cover
Rear.

Please see the hook of the Cover
Left. Pull the Hook and release it
from the frame.

Pull

Slide the Cover Left to the
backward with pulling the hook out.

The Cover Left can be easily
removed.

4-3-3. Cover Front

Please see the MP tray disassembly. (4-9)

4-3-4. Cover Main

Cover Open

Open the Cover Open.
Remove two screws.

Cover Top

Screw

Cover Main

Up

Screw

See the hooks.
Push the hooks up and pull them
upward.

With holding Cover Main, remove
the panel wire.

4-3-5. Cover Rear

®Ë

®Á

Cover Rear

Stripe

Open the Cover Rear.
Detach the stripe by pushing the
stripe.
There is a hook holding the stripe.

Hinge

After detaching the stripe from the
Cover Rear,
Release the Cover Rear from the
hinge.

4-4 Video Controller board & Joint board

°‹

After removing external cabinet,
see the 5 screws and you should
remove them.
The Shield ICU is important for EMI
and protection for Controller.

Shield ICU

Joint Board

Screw

After removing Shield ICU, you can
see the assembled controller.
Unplug the panel cable and engine
I/F cable with care and remove the
screws from the frame.

Panel Cable

Controller

Board

RAM Simm Socket

Engins I/F cable

Flash SIMM or

Postscript SiMM

Socket

Frame ICU

Screw
Parallel

I/F
reserved for

Network
reserved for

Serial
Screw

Remove the screws which hold the
Bracket ICU to the frame and deta­ch controller from the frame.
You can see the Frame ICU.

Video Controller Board

ASIC(QP1700)

ASIC

(Powerbridge)
Connector for

Network

ASIC

(Hype chip)

Power PC processor

4-5 Fuser Ass’y

Open the Cover Rear and see the
screws and unscrew and remove
the Cover pcb.

Screw

Cover pcb

for engine B’d

After removing the Cover pcb,
unplug the Thermistor connetor
from the Engine Board.

Thermistor

connector

See the 4 screws which hold the
fuser assy to the frame. You should
unscrew and pull the fuser out and
it will be removed.
The AC connector for fuser is des­igned to be directly connected to
the AC socket which is positioned
in the frame.

Screw
Screw

< Fuser Ass’y >

exit sensor

actuator

When Jam happens, you can easily

®Á

®Ë

remove it by pulling the Guide Rear
out like figure. In order to remove
Guide Rear, opening the Guide
Rear out like figure and pull out
hinge of Guide Rear.

Guide Rear

4-6 Bracket Motor Ass’y & Cover Open Switch Unit

Bracket Motor ass’y is located in
the right-upper side. Remove 7
black screws and detach the ass’y
from the frame and unplug the
motor connector from the motor.

Motor

Bracket Motor Ass’y

You can see the Bracket Motor ass’y.
Motor and several gears are ass­embled in one gear bracket.

< Bracket Motor Ass’y >

Cover Open Switch unit

After removing the Bracket Motor
ass’y, you can see the Cover Open
Switch Unit.
Remove the SMPS.
Refer to SMPS & Bracket
Duplex Ass’y disassembly (4-12)
Detach two Connectors form the
SMPS.
Remove 2 screws and detach the
unit from the frame.

4-7 Pickup Ass’y

After running about more than
100,000 pages, the pickup ass’y
may be needed to be replaced
depending on feeding quality.
Remove the screw of Bracket
Support and tension spring.

Pickup Ass’y

Tension Spring

Screw

Lift Guide Front Duplex and
remove the 3 mounting screws of
Pickup Ass’y.

Guide Front Duplex

Screws

4-8 Laser Scanner Unit

Cover Top

Cap-wire LSU

Laser Scanner Unit is located in the upper frame.
In order for LSU disassembling, disassemble the Cover Main, you should take off the left and
right cover.
There is wiring protection cover(Cap Wire LSU)for LSU wires.
Remove Cap wire LSU.

There are two wires for LSU. One is LSU motor and the other is Laser beam control. The wires
are wire to wire types. You can easily disconnect the wires. After disconnection, unscrew and

remove LSU.

4-9 Multi Purpose Tray

Remove the Cover main.

Hook

See the Links which hold the MP tray
in the both side.
Hold the Links and pull it to the arrow
direction.

Hold the MP tray and pull it to the
arrow direction.

Screw

Hook

Cover Front

After detaching the Tray MP, see the screws and remove them.

Remove the hook and release the Cover Front by releasing the hook.

Screw

Screw

Screw

Screw

After removing Cover Front, detach
the MP ass’y by unscrewing 4
screws.

< MP Assy >

Before detaching MP Ass’y, unplug
the MP solenoid and MP sensor
connector from the Joint Board.

4-10 Control Panel

LCD Ass’y

Cover Open

First lift up Cover Main and see the panel wire and disconnect the wire from the panel board. And
next step is to remove the panel board which is located in the Cover Top.
Control panel consists of LCD ass’y and Key&LED ass’y.
Remove Key&LED ass’y and remove LCD ass’y.

Cover Top

LCD Ass’y
Hook

Cover Top
Hinge

After removing Key&LED ass’y, release the hook of LCD assy from Cover Top and see the hinge
for LCD ass’y in the cabinet and release them.
You should spread the hinge of LCD ass’y.
But be careful not to damage the hinge.

4-11 Engine Controller Board

Screw

Paper

wire

In order for disassembling PCU, the
printer should be turned upside down.
When turned over, toner may contamin­ate LSU window. Open the Cover Top
and you should insert one paper into
the inner like above figure.

Open the Cover Rear and remove the
Cover PCB.

After removing Cover Rear, disconnect
all wires from the PCU. and then
remove the screw of Ground Shield
SMPS, Turn over the printer.

Bar Cross Bottom

CST Sensor

After turning over, remove Bar cross Bottom by unscrewing them 8 screws.
Next remove the CST Sensor and remove the screws in the PCU which are black colored
screws.

After unscrewing, lift the PCU like above figure. And you can see the connector which are LSU’s
and ‘Video I/F’s’. Unplug them with care. Be careful not to be hurt to your hands when you

disconnect the wires because the connection is tight and you may pull the connectors strongly.

PCU room

< PCU Ass’y >

Above is to show the disassembled PCU and Frame. PCU Assy has some sensor, some
actuator, solenoid and Shield plate and HVPS circuit. Service man could ask the Assy or repair
parts.

Screw
Screw
Screw
Screw

In order to remove SMPS, first remove Cover Left.
Use your left hand to release hook from the frame and slide the Cover Left to backward by use of
right hand. After removing Cover Left, you can see the SMPS. Unplug the power connector and
release the wire from the wire guide of the SMPS.
Remove four screws and separate SMPS from the frame.
You can see the fuser AC connector and +5V, +24V connector which are connected to the
microswitches. Detach the wires from the SMPS.

There are 4 connectors to the SMPS. The power connector is +5V and +24V output from SMPS.
AC for fuser is AC output from SMPS to the fuser. And there are microswitches whice are
attached to the upper frame and which are attached to the upper frame and which are shorted
when Top cover is closed, namely interlock Switches for +24V for HVPS, motor and for +5V for
Laser beam.

The Bracket Duplex Ass’y is located in the left upper side. Remove the screws and detach the
ass’y from the Frame.
In order to remove the connector of Solenoid, first remove Engine Controller Board.
Refer to Engine Controller Board disassembly (4-11)

+24V

AC Connector +5V

Bracket Duplex Ass’y

4-13 Transfer Roller Ass’y

Open the Cover Top, you can see colored levers at each side of Transfer Roller, push the levers

which is attached in the Holder transfer Roller to release the Ass’y.

Holder Transfer Roller

5. Troubleshooting

5-1 Print Quality

Error status Check Solution

1. Check HVPS output voltage 1. Refer to HVPS output spec

Dark Image

Light Image 2. Check HVPS output voltage 2. Refor to HVPS output spec.

Horizontal Density with present one
Band. 2. Contamination of Transfer 2. Replace transfer roller

Print Contamination

Toner on Backside - Refer to “4-5”
of printer page 2. Contamination of transfer Roller 2. Replace Transfer Roller

Back Ground

Vertical Black Streak 1. OPC Drum scar 1. Clean OPC Drum
and band 2. OPC Drum damage 2. Replace image cartridge

Vertical White Streak

Partial Black Image If not improved,
(periodic) replace image cartridge.

Partial White Image 1. OPC Drum scar or particle 1. Clean OPC Drum
(not periodic) 2. Check the cartridge life 2. Replace image cartridge

2. Check terminal contact for - Replace the engine board
HVPS. - Refer to “4 - 11”

2. Fix the terminal to contact well.

1. Check the toner quantity. 1. Replace image cartridge.

3. Check the terminal contact for -Replace the engine board.
HVPS. 3. Fix the terminal to contact well.

1. Compare new image cartridge 1. Replace image cartridge

Roller

1. Contamination of Fuser Unit 1. Clean Fuser Unit or change

If not improved, replace it.

2. Contamination of Heat roller 2. Clean Heat Roller

- Refer to “4-5”

3. Contamination of OPC Drum 3. Clean OPC Drum.

If not improved, replace image
cartridge.

1. Contamination of Fuser Unit 1. Clean Fuser Unit.

If not improved, replace it.

3. Contamination fo paper path 3. Remove the contamination on

paper path.

1. Check HVPS output voltage 1. Refer to HVPS output spec

2. OPC Drum contamination or - Replace the engine board
image cartridge life 2. Replace the image cartridge

3. Check the contamination of 3. Clean the lens with a soft
PTL lens dry cloth

4. Check the terminal contact for 4. Fix the terminal to contact well.
HVPS.

5. Check the contamination fo transfer 5. Relpace Transfer Roller
roller.

1. Contamination of LSU window 1. Clean LSU window

2. If not improved,
replace image cartridge

1. OPC Drum scar or particle 1. Clean OPC Drum & roller

2. Heat roller scar or particle 2. Cleaning heat roller

3. Develope roller scar or particle 3. Clean the develope roller.

4. Charge roller scar or particle 4. Clean the charge roller.
If not improved,
replace image cartridge.

Error status Check Solution

1. Check HVPS voltage 1. Refer to HVPS output spec.

- Replace the engine board

2. Check the GND OPC contact. 2. Fix contact points to fit well.

- Contact among GND OPC
contact points.

- Image cartridge.

- GND OPC terminal on frame

- GND OPC terminal on the

No image (all white) engine board

- Confirm the voltage between
GND-OPC and GND-Frame.
: -130V approx

3. Check LSU operation. 3. Replace the LSU.

- Refer to DCU control “05” -Refer to “4-8”

4. Compare new video board 4. Replace the video board.
with present one.

5. Toner empty 5. Replace the image cartridge.

1. Check the charger voltage 1. Refer to HVPS output spec

All Black Image 2. Check the terminal contact - Replace the engine board

3. Compare new video board with 2. Replace terminal
present one 3. Replace video board

5-2 HVPS Output Spec

¶°- 130 V

°›Recommanded Test Equipment

- DVM -High Voltage Probe

DCU CODE NO. HVPS OUTPUT REMARK

CHARGER “01” - 1.55 KV
TRANSFER “-” “02” -1KV~ -1.4KV
TRANSFER “+” “03” +1.8 KV
BIAS “04” - 500 V
SUPPLY “04” - 700 V
OPC GND

1. Turn off the printer

2. Open the rear cover and disassemble

3. Connect the DCU on engine board and

4. Open the top cover.

5. Remove image Cartridge.

6. Push the Cover Open Switch

7. Select the Diagnostic mode and

the cover-shield.

close the rear cover.

measure HVPS output.

5-3 Malfunction

•ÿis opened. replace it.

220V version - 5~6•ÿ

2. Check themistor wire assembly defect. 2. If the thermistor wire of the fuser unit

Internal Error 11 Normal : 2~400k•ÿis defected, replace it.
(Fuser Error) 3. Check SMPS 3. If the fuser unit is normal,

- CN2 conection on SMPS replace SMPS.

- Fuse(F2) open

- Defect of component related to Fuser
control.

4. Check Engine Board 4. If not normal operation after replacing

- CN7 connection it, replace the engine board.

- Fuser control line:

Cn5-2 level (Lamp on : 0.2V, Lamp off:24V)

Check the Cover Open operation 1. Replace cover open Unit

1. Cover open unit defect -Refer to “4-6”

Cover open 2. Cable damage and connection 2. Replace cover open switch

3. Engine board defect assembly, and connect properly.

3. Replace the engine board.

Error status Check Solution

1. Check FUSE 1. Replace SMPS.

- F1(8A), F2(5A) OPEN. - Refer to “4-12”

No Power

2. Check FUSE. 2. Measure the resistance +5V and GND.

- F3(250V/3A) OPEN. (Engine board CN5-pin6 and CN5­pin9). If find the short circuit, replace
the Engine board.

1. Check Fuser unit To disassemble the Fuser unit,

- Thermostat open refer to “4-5”.

- hallogen lamp defect 1. If the thermostat of the fuser unit

Normal : 110V version - 2~3

Error status Check Solution

®MVideo controller - Refer to “4-4”

board J11.) 2. Replace Engine board.

2. Engine board defect.

1. Check the exit sensor. 1. Replace Exit sensor.

- Refer to DCU mode “08” - Refer to “4-11”

2. Check the exit sensor actuator. 2. Replace Exit sensor actuator.
Jam 2 3. Check the Exit Roller. - Refer to “4-5, 6-6”
“Paper is stopped 4. Check the Cover Rear. 3. Replace Exit Roller.

just after exit sensor” 5. Check the Contamination of Fuser Unit - Refer to “4-3, 6-1”

4. Replace Cover Rear.

- Refer to “6-1”

5. Replace or Clean Fuser Unit

- Refer to “4-5, 6-6”

1. Check the operation of Duplex Clutch 1. Replace Duplex Clutch.

- Refer to DCU mode “12” - Refer to “4-6”

2. Check the Duplex sensor 1. 2. Replace the DS1 on Engine Board.

- Refer to DCU mode “07” 3. Replace Duplex sensor 1 actuator.

Duplex Jam 1 3. Check the Duplex sensor 1 actuator. - Refer to “4-11”

4. Check the Cover Rear. 4. Replace Cover Rear.

5. Check the bracket duplex unit - Refer to “6-1”

6. Check the duplex solenoid. 5. Replace bracket duplex unit

The resistance of duplex solenoid: - Refer to “6-8”

40~50 ohm. 6. Replace duplex solenoid ass’y.

1. Check the Duplex sensor 2. 1. Replace the DS2 on Engine board.

- Refer to DCU mode “07” 2. Replace Duplex sensor actuator.

Duplex Jam 2 2. Check the Duplex sensor 2 actuator. 3. Replace Gear of shield pcb

3. Check the Gear of shield pcb - Refer to “4-11, 6-7”

- Check all the gear for correct installation

1. Check the LED Array. 1. Replace LED Array.
PTL Error

(Pre Transfer Lamp)

Toner Empty 3. Check Joint board 3. Replace Joint board.

OUT-BIN Full 2. Check OUT-BIN sensor actuator. actuator.

Internal Error 20
(Engine Error)

2. Check the cable connection or wire defect. - Refer to “6-2”

3. Check Joint board. 2. Replace harness or reconnection.

3. Replace Joint board.

- Refer to Disassembly

1. Check image cartridge life 1. Replace image cartridge.

2. Check Toner sensor contact. 2. Replace harness or reconnection.

4. Compare new image with present on. - Refer to “4-4”

4. Replace image cartridge.

1. Check OUT-BIN sensor. 1. Replace OUT-BIN sensor.

- Refer to DCU mode “09” 2. Replace OUT-BIN sensor

3. Check cable connection or wire defect 3. Connect the cable correctly or replace

the cable.

1. Check the Cable between Engine and 1. Connect the cable correctly or

Video controller. replace the cable.

(Engine board CN10

Error status Check Solution

•ÿ2. Replace PAD

exitted from cassette 2) Check PAD of Pickup roller - Refer to “4-9, 6-4”

3) Check Joint board 3. Replace Joint board.

2. Paper is stopped Measure the CN503-2pin - Refer to “4-4”
before feed sensor. 4) Check the Gear of multi Purpose 4. Replace Pickup Unit Gear.

Pickup Unit 5. Connect the cable correctly

5) Check cable connection or wire defect. or replace the cable.

3. Second cassette feeding

1) Check Pickup Clutch for SCF. 1. Replace the pick-up clutch for SCF.

- The resistance of SCF solenoid: 70~80•ÿIf not improved, replace SCF board

2) Check PAD of Pickup roller 2. Replace PAD.

3) Check the Gear of pickup Unit - Refer to “6-11”

4) Check paper installation in cassette. 3. Replace Pickup Unit Gear.

5) Check cable connection or wire defect. - Refer to “6-11”

4. Reinstiall paper properly.

5. Connect the cable correctly, or
replace the cable.

1. Check the Feed sensor. 1. Replace Feed Sensor.
Jam 1 - Refer to DCU mode “08” - Refer to “4-11”
“Paper is stopped 2. Check the Feed Sensor actuator 2. Replace Feed Sensor actuator.

on feed sensor” 3. Check the paper installation in - Refer to “4-11, 6-2”

cassette. 3. Reinstall paper properly.

1. Check the DC supply for laser 1. If +5Vs for laser diode isn’t supplied.
scanning unit check the cover switch assembly for

+5Vs and fix it,

Internal Error 10 2. Check laser scanning unit 2. If the DC power supply for laser

(Scanner Error) - Refer to DUC mode “05” scanning unit has normal operation,

replace the laser scanning unit

3. Check the cable connection and defect 3. Replace cable and connect properly.

4. Engine board. 4. If not normal operation after replacing

it, replace the engine board.

1. 1st cassette feeding

1) Check the operation of Pick-up Clutch 1. Replace the Pick-up solenoid on

- Refer to DCU mode “06” Engine Board.

- Refer to “4-11”

2) Check PAD of Pickup roller. 2. Replace PAD.

- Refer to “4-7, 6-5”

3) Check the Gear of Pickup Unit. 3. Replace Pickup Unit Gear.

- Refer to “4-7, 6-5”

4) Check paper installation in cassette 4. Install paper properly.

2. Multi purpose feeding

1) Check the operation of 1. Replace MP solenoid.
multi purpose Clutch If not normal operation after replacing

- Refer to DCU mode “13” it, replace the engine board.

Jam 0 - Check MP solenoid. - Refer to “4-11”.

1. Paper is not The resistance of MP solenoid 70~80

Error status Check Solution

•ÿapprox.

4. Check the Engine board.

5. Check Gear of Motor Drive Unit.

- Check all the gear for correct
installation.

1) 1’st Cassette Feeder

1. Check the paper empty sensor 1. Replace the paper empty sensor on

- Refer to DCU mode “07” Engine board.

2. Check the paper empty sensor actuator. 2. Replace paper empty sensor actuator.

2) Multi Purpose Feeder

1. Check the paper empty sensor for MP. 1. Replace MP sensor assembly.

Paper Empty - Refer to DCU mode “07” 2. Replace MP paper empty sensor

2. Check the MP paper empty sensor actuator.
actuator. If not improved, replace

the engine board

3) Second Cassette Feeder

1. Check the paper empty sensor for SCF 1. Replace the paper empty sensor on

- Refer to DCU mode “07” S.C.F board.

2. Check the paper empty sensing actuator 2. Replace MP paper empty sensor

for SCF. actuator.

- Refer to DCU mode “00”

1. Check the supply voltage. (+24Vdc) 1. Replace to cover open unit.

Engine board CN1 -2,5 pin 2. Replace cable

2. Check the Motor cable for cuts or 3. Replace Motor.
pinched wiring. 4. Replace Engine board.

Main Motor 3. Check the resistance for Motor between 5. Replace Motor Drive Unit

pin No. 1 to 3(4 to 6) - Refer to “4-6, 6-9”
The resistance of motor : 3

5-4 .Connector Pin Assignment

5-4-1. Engine Board Connector Pin Assignment

CONNECTOR PIN-NO DESCRIPTION IDLE ACTIVE IN/OUT

1 MOTOR_PB* +24V PULSE O

CN1

MOTOR

CN2 1 +24V +24V +24V O

DUPLEX 1 D_CLUTCH +24V L -

CN3

FAN

CN4

CASSETTE

BOARD

CN5

SMPS

CN6 8 SCF_READY H L I

JOINT BOARD 10 STS_SCF PULSE PULSE I

INTERFACE 11,13 AGND AGND AGND -

CN7 1 THERMISTOR - - -

THERMISTOR 2 THERMISTOR - - -

CN8 2 DCU_DATA PULSE PULSE I/O

DCU 3 DCU_CLK CLOCK CLOCK O

2.5 +24V +24V +24V ­3 MOTOR_PB +24V PULSE O
4 MOTOR_PA* +24V PULSE O
6 MOTOR_PA* +24V +24V O

1 +24V +24V +24V ­2 NC NC NC ­3 FAN +24V L O
1 CAST_SENS1 H L I
2 CAST_SENS2 H L I
3 CAST_SENS3 H L I
4 DGND DGND DNGD ­1 +24VS2 +24V +24V ­2 FUSERON +24V L O

3,5,7 AGND AGND AGND -

4 +5Vs +5V +5V -

6,8,10 +5V +5V +5V -

9,11,12 DGND DGND DGND -

13,14,15,16 +24VS2 +24V +24V -

1,2,3 +5V +5V +5V -

4 MP_CLUTCH L 0.7V O
5 +5Vs +5V +5V ­6 Q_LAMP L 0.7V O

7,9 +24VS2 +24V +24V -

12 MP_PAPER H L I
14 TONER H L I

15,17 DGND DGND DGND -

16 CMD_SCF PULSE PULSE O
18 OPT_CLK PULSE PULSE O

1 +5V +5V +5V -

4 DGND DGND DGND -

CONNECTOR PIN-NO DESCRIPTION IDLE ACTIVE IN/OUT

1.4 DGND DGND DNGD ­2 VDO H L O
3 LDON H L O

CN9
LSU

C N 1 0 6 P R I N T H L I

V I D E O 7 V D I H L I

C O N T R O L L E R 8 C P R D Y - -

I N T E R F A C E 9 P S Y N C H - O

5 +5Vs +5V +5V ­6 HSYNC H L I
7 LREADY H L I
8 PMOTOR +24V L O
9 AGND AGND AGND -

10 +24VS2 +24V +24V -

1 EBUSY H L O

2 , 1 7 , 1 9 , 2 0 , 2 1

2 2 , 2 3 , 2 4

3 E M S G H L O
4 E X I T _ P A P H L O
5 C C L K H P U L S E I

1 0 R E A D Y H L O
1 1 H S Y N C H L O
1 2 N C N C N C -

1 3 , 1 5 , 1 6 , 1 8

2 5 , 2 7 , 2 8

1 4 C M S G H I

D G N D D G N D D N G D -

+ 5 V + 5 V + 5 V -

5-4-2. Joint Board Connector Pin Assignment

CONNECTOR PIN-NO DESCRIPTION IDLE ACTIVE IN/OUT

1,2,4 +5V +5V +5V -

3 MP_CLUTCH L 0.7V O
5 Q_LAMP L 0.7V O
6 +5Vs +5V +5V ­7 SCF_READY H L I

CN501 8,10 +24VS2 +24V +24V -

JOINT BOARD 9 STS_SCF PULSE PULSE I

INTERFACE 11 MP_PAPER H L O

12,14 AGND AGND AGND -

13 TONER H L I
15 CMD_SCF PULSE PULSE O

16,18 DGND DGND DGND -

17 OPT_CLK PULSE PULSE O

1 +5V +5V +5V ­2 AGND AGND AGND -

CN502

SCF

INTERFACE

CN503 1 +24V +24V +24V -

MP_CLUTCH 2 MP_CLUTCH +24V L O

CN504 1 +5V +5V +5V -

Q_LAMP 2 Q_LAMP +5V L O

CN505

MP_SENSOR

CN506

TONER

3 +24V +24V +24V ­4 STS_SCF PULSE PULSE O
5 CMD_SCF PULSE PULSE I
6 OPT_CLK PULSE PULSE I
7 SCF_READY H L O
8 DGND DGND DGND -

1 MP_SENSOR H L I
2 DGND DGND DGND ­3 +5V +5V +5V ­1 +5V +5V +5V ­2 TONER H L O
3 AGND AGND AGND -

5-4-3. S.C.F Board Connector Pin Assignment

CONNECTOR PIN-NO DESCRIPTION IDLE ACTIVE IN/OUT

1 +5V +5V +5V ­2 AGND AGND AGND -

CN1 3 +24V +24V +24V -

ENGINE 4 STS_SCF PULSE PULSE O

JONIT BOARD 5 CMD_SCF PULSE PULSE I

INTERFACE 6 OPT_CLK PULSE PULSE I

7 SCF_READY H L O
8 DGND DGND DGND ­1 MOT_PA +24V PULSE -

CN2 2 MOT_PB +24V PULSE O

MOTOR 3 MOT_PA* +24V PULSE O

4 MOT_PB* +24V PULSE O
1 +5V +5V +5V -

CN3 2 DCU_IN/OUT PULSE PULSE I/O

DCU 3 DCU_CLK CLOCK CLOCK O

4 DGND DGND DNGD -

CN4 1 +24V +24V +24V -

PICK UP 2 CLUTCH +24V L O

1 CASET_1 H L I

CN5 2 CASET_2 H L I

CASSETTE 3 CASET_3 H L I

4 DGND DGND DNGD -

5-5 .Troubleshooting of Video Controller

Most electronic products are sensitive to connectors and assemblies that are not complete seated. Therefore, before
starting the troubleshooting procedure, do a mechanical check of all the connectors and assemblies to make sure that
everything is properly seated.

1. For a complex malfunction, check first for a bad weld, short circuit or loose wire on the solder area of the board

2. Input low level is standard for the TTL logic level below 0.8V.
Input high level is standard for the TTL logic level above 3.5V.
But, for PowerPC 603e, the input low level is less than 0.8V, and the input high level is more than 2.0V.

3. USE an oscilloscope or logic analyzer for inspecting the crystal oscillator or its waveform.

5-5-1. Troubleshooting Flow Chart

Power Error

System Error

Engine Error

Self Test Error

Parallel Interface Error

Printing Error

5-5-2. Troubleshooting Table of Video Controller Board

NO. Error Type Ckeck List Repair

Power cord connection Connect the power cord
Vcc voltage(nominal is +5V) level Refer to the section of
Vcc voltage should be in the range between+4.38-+5.2V Engine troubleshooting

The backlight Short Between Vcc and GND Repair board

1 of LCD is not Mutual connection of engine, key panel to LCD

lit up panel’s connected cable(10pin), video board to key Connect the cable to

panel’s connected cable(20pin) and engine interface connector
cable(28pin)
The pin of connector is straigh.
Mutual connection of panel cabel(10pin) Confirm the connection
video board to key panel’s connected cable(20pin) of connector

Repair or replace it

It doesn’t If uanable to do this,
displayed replace video board.

2

characters on Any foreign conductive chips of solder or material Remove any foreign

Any component damage on a video controller board.

with appropriate tools.

LCD is on the video controller board or is laid between conductive chips on the

IC pins after power off. video controller board.
Reset Error:Reset signal is normal high during operation
System source clock is a 50ß÷
Check point : U16(FS741)’s pin No.6, Replace the FS741
The output clock of QP17000 is a 25ß÷.

The input clock of CPU(U26) and U24 is a 25ß÷. Replace the board
The video data colck source is a 62.7639ß÷at OSc2
The input clock of U31 is a 62.76397ß÷.

3 White copy The output clock of U31 is a 16ß÷.

The input clock of U2’s pin No.125 is a 16ß÷. Replace the board
°·Check the normal operation of HSYNC* and PSYNC* Active low impulse

4 DRAM Error

5 EEPROM

6 ROM Error
7 Engine Error °·Refer to the section of Engine troubleshooting

Parallel

8 Interface

Error cable
General desc- °·Please refer to the user’s manual.

riptions of °·If you can’t fix the trouble of video controller

9

troubleshooting board, replace the video board by the verified

°·Check the DRAM address signals.(pin No. 17-20, 23-28 : U20, U290)
°·Check the DRAM data signals. (pin No. 2-5. 7-10. 33-36. 38-41 : U20, U29)
°·Check the EEPROM clock signal. (pin No. 2 : U1)
°·Check the EEPROM data signals. (pin No. 3,4 : U1)
°·Check the ROM chip select signals and read signal (pin No. 12,14)
°·CHeck the ROM data signals. (pin No. 15-22, 24-31 : U25, U27, U30, U32)

°·CHeck the operation of printer driver.
°·Check the printer cable(bidirectional cable)

board.

Refer to USER’s manual
Replace the printer

Replace the board