Epson GT-1200 User manual

EPSON
EPSON
EPSON France S.A.
SERVICE MANUAL
GT-1200
PRODUIT

SERVICE MANUAL
ColorImageScanner
EPSON GT-12000
4008511
®

NOTICE
n
All rights reserved. No part of this manual may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic,
mechanical, photocopying, recording, or otherwise, without the prior written permission of SEIKO EPSON CORPORATION.
n
The contents of this manual are subject to change without notice.
n
All effort have been made to ensure the accuracy of the contents of this manual. However, should any errors be detected, SEIKO EPSON would greatly
appreciate being informed of them.
n
The above not withstanding SEIKO EPSON CORPORATION can assume no responsibility for any errors in this manual or the consequences thereof.
EPSON is a registered trademark of SEIKO EPSON CORPORATION.
General Notice: Other product names used herein are for identification purpose only and may be trademarks or registered trademarks of their respective
owners. EPSON disclaims any and all rights in those marks.
Copyright © 1996 SEIKO EPSON CORPORATION. Printed in Japan.

PRECAUTIONS
Precautionary notations throughout the text are categorized relative to 1)Personal injury and 2) damage to equipment.
DANGER
Signals a precaution which, if ignored, could result in serious or fatal personal injury. Great caution should be exercised in performing
procedures preceded by DANGER Headings.
WARNING
Signals a precaution which, if ignored, could result in damage to equipment.
The precautionary measures itemized below should always be observed when performing repair/maintenance procedures.
DANGER
1. ALWAYS DISCONNECT THE PRODUCT FROM THE POWER SOURCE AND PERIPHERAL DEVICES PERFORMING ANY MAINTENANCE OR
REPAIR PROCEDURES.
2. NOWORK SHOULD BE PERFORMED ON THE UNIT BY PERSONS UNFAMILIER WITH BASIC SAFETY MEASURES AS DICTATED FOR ALL
ELECTRONICS TECHNICIANS IN THEIR LINE OF WORK.
3. WHEN PERFORMING TESTING AS DICTATED WITHIN THIS MANUAL, DO NOT CONNECT THE UNIT TO A POWER SOURCE UNTIL
INSTRUCTED TO DO SO. WHEN THE POWER SUPPLY CABLE MUST BE CONNECTED, USE EXTREME CAUTION IN WORKING ON POWER
SUPPLY AND OTHER ELECTRONIC COMPONENTS.
WARNING
1. REPAIRS ON EPSON PRODUCT SHOULD BE PERFORMED ONLY BY AN EPSON CERTIFIED REPAIR TECHNICIAN.
2. MAKE CERTAIN THAT THE SOURCE VOLTAGES IS THE SAME AS THE RATED VOLTAGE, LISTED ON THE SERIAL NUMBER/RATING PLATE. IF
THE EPSON PRODUCT HAS A PRIMARY AC RATING DIFFERENT FROM AVAILABLE POWER SOURCE, DO NOT CONNECT IT TO THE POWER
SOURCE.
3. ALWAYS VERIFY THAT THE EPSON PRODUCT HAS BEEN DISCONNECTED FROM THE POWER SOURCE BEFORE REMOVING OR REPLACING
PRINTED CIRCUIT BOARDS AND/OR INDIVIDUAL CHIPS.
4. IN ORDER TO PROTECT SENSITIVE MICROPROCESSORS AND CIRCUITRY, USE STATIC DISCHARGE EQUIPMENT, SUCH AS ANTI-STATIC
WRIST STRAPS, WHEN ACCESSING INTERNAL COMPONENTS.
5. REPLACE MALFUNCTIONING COMPONENTS ONLY WITH THOSE COMPONENTS BY THE MANUFACTURE; INTRODUCTION OF SECOND-
SOURCE ICs OR OTHER NONAPPROVED COMPONENTS MAY DAMAGE THE PRODUCT AND VOID ANY APPLICABLE EPSON WARRANTY.

PREFACE
This manual describes basic functions, theory of electrical and mechanical operations, maintenance and repair procedures of GT-12000. The instructions and
procedures included herein are intended for the experienced repair technicians, and attention should be given to the precautions on the preceding page. The
chapters are organized as follows:
CHAPTER 1. PRODUCT DESCRIPTIONS
Provides a general overview and specifications of the product.
CHAPTER 2. OPERATING PRINCIPLES
Describes the theory of electrical and mechanical operations of the product.
CHAPTER 3. TROUBLESHOOTING
Provides the step-by-step procedures for troubleshooting.
CHAPTER 4. DISASSEMBLY AND ASSEMBLY
Describes the step-by-step procedures for disassembling and assembling the
product.
CHAPTER 5. ADJUSTMENTS
Provides Epson-approved methods for adjustment.
CHAPTER 6. MAINTENANCE
Provides preventive maintenance procedures and the lists of Epson-approved
lubricants and adhesives required for servicing the product.
APPENDIX
Provides the following additional information for reference:
• Connector pin assignments
• Electric circuit boards components layout
• Exploded diagram
• Electrical circuit boards schematics

REVISION STATUS
Rev. Date Page(s) Contents
A 1997/10/20 All First release

TABLE OF CONTENTS
PRODUCT DESCRIPTIONS
1.1 OVERVIEW....................................................................................................................................................................1-1
1.2 SPECIFICATION ...........................................................................................................................................................1-1
1.3........................................................................................................................................................................................1-4
1.3 INTERFACE SPECIFICATION ......................................................................................................................................1-4
1.4 CONTROL CODE..........................................................................................................................................................1-5
1.5 OPERATION SPECIFICATIONS...................................................................................................................................1-6
1.5.1 Switch Specification...........................................................................................................................................................................1-6
1.5.2 LED Specification ...............................................................................................................................................................................1-6
1.5.3 Switch Setting.....................................................................................................................................................................................1-7
1.5.4 Error Indication...................................................................................................................................................................................1-7
1.5.5 Readable Area.....................................................................................................................................................................................1-8
1.5.6 Transportation Screw.........................................................................................................................................................................1-8
OPERATING PRINCIPLES
2.1 GENERAL DESCRIPTION ............................................................................................................................................2-1
2.2 MECHANISM OPERATING PRINCIPLES.....................................................................................................................2-2
2.3 ELECTRICAL CIRCUIT OPERATIONS.........................................................................................................................2-3
2.3.1 Control Circuit Operation...................................................................................................................................................................2-3
2.3.2 Power Supply Circuit Operation........................................................................................................................................................2-5

TROUBLESHOOTING
3.1 OVERVIEW....................................................................................................................................................................3-1
3.1.1 Error Detection by the Self-Diagnostic Function.............................................................................................................................3-1
3.1.2 Troubleshooting .................................................................................................................................................................................3-2
3.1.2.1 Test Points................................................................................................................................................................................3-2
3.1.2.2 Check Points for Abnormal Phenomenon.................................................................................................................................3-2
3.1.3 Troubleshooting for Electrical Circuit ..............................................................................................................................................3-8
3.1.3.1 Power Supply Board (B054PSH Board)....................................................................................................................................3-8
3.1.3.2 Control Circuit Board (B054MAIN Board)..................................................................................................................................3-9
DISASSEMBLY AND ASSEMBLY
4.1 OVERVIEW....................................................................................................................................................................4-1
4.1.1 Tools....................................................................................................................................................................................................4-1
4.1.2 Screws.................................................................................................................................................................................................4-1
4.2 DISASSEMBLY PROCEDURES ...................................................................................................................................4-2
4.2.1 Electrical Circuit Removal..................................................................................................................................................................4-3
4.2.1.1 EPROM Replacement...............................................................................................................................................................4-3
4.2.1.2 MAIN/B054PSH Board Removal...............................................................................................................................................4-4
4.2.2 Scanner Body Disassembly...............................................................................................................................................................4-5
4.2.2.1 Upper Housing Removal...........................................................................................................................................................4-5
4.2.2.2 Scanner Mechanism Removal ..................................................................................................................................................4-6
4.2.3 Scanner Mechanism Disassembly....................................................................................................................................................4-7
4.2.3.1 Panel Board Assembly Removal...............................................................................................................................................4-7
4.2.3.2 Sub Board Assembly Removal..................................................................................................................................................4-8
4.2.3.3 HP Sensor (CR) Removal.........................................................................................................................................................4-9
4.2.3.4 CR Motor Assembly Removal .................................................................................................................................................4-10

4.2.3.5 Glass Frame Assembly Removal and Pre-operation ..............................................................................................................4-11
4.2.3.6 Lamp Assembly and Inverter Board Assembly Removal ........................................................................................................4-14
4.2.3.7 HP (AF) Sensor Removal........................................................................................................................................................4-16
4.2.3.8 AF Motor Assembly Removal.................................................................................................................................................4-17
4.2.3.9 AF Motor Assembly Installation...............................................................................................................................................4-18
4.2.3.10 Option Frame Assembly Removal.........................................................................................................................................4-19
ADJUSTMENT
5.1 OVERVIEW....................................................................................................................................................................5-1
MAINTENANCE
6.1 OVERVIEW....................................................................................................................................................................6-1
6.1.1 Cleaning...............................................................................................................................................................................................6-1
6.1.2 Lubrication..........................................................................................................................................................................................6-1
APPENDIX
7.1 OVERVIEW....................................................................................................................................................................7-1
7.1.1 Connector Pin Assignment................................................................................................................................................................7-1
7.1.2 Connector Summary...........................................................................................................................................................................7-1
7.2 COMPONENT LAYOUT ................................................................................................................................................7-6
7.3 CIRCUIT DIAGRAMS ....................................................................................................................................................7-8
7.4 EXPLODED DIAGRAMS.............................................................................................................................................7-10

PRODUCT DESCRIPTIONS
CHAPTER
1

GT-12000 Product Descriptions
Rev. A 1-1
1.1 OVERVIEW
The GT-12000 is an A3 size flat-bed type color image scanner. The main
features of the scanner are:
q High resolution
Optical resolution is 800 dpi.
q Wide readable area
Accommodates up to A3 size.
q High-quality image
12bit A/D input/output (optical density is 3.0.)
q High-speed scanning
Scanning A3/Portrate At 800dpi / Draft-mode;
Full-color = Approx. 15mS/line
256 Gray = Approx. 10.8mS/line
Line art = Approx. 10.8mS/line
q Adjustable Focusing function
Adjustable up to 5mm above the surface of document table.
q Quick operation
Xe-Gas Cold Cathode Fluorescent Lamp allows no initial light-up for
immediate scanning.
q New command level: ESC/I-B8 (B6 level with Focus control)
q Optional unit enhancing the function of the unit
n Transparency Unit
n Duplex scanning ADF (Automatic Document Feeder)
1.2 SPECIFICATION
GENERAL
Type: Flat-bed color image scanner
Scanning Method: Sub-Scanning mirror movement system
Photoelectric Device: Color CCD Line sensor
Color Separation: Color filter separation
Light Source: Xe-Gas Cold Cathode Fluorescent Lamp
Scanning Resolution: 800 (Main) by 800 (Sub) dpi
Output Resolution: 50 to 3200dpi (1dpi increment)
Effective Picture Element: 9760 by 13760 pixel (Max.)
Maximum Readable Area: 12.2 by 17.2 inch (310 by 437mm)
Scanning Speed: At 800 dpi / Draft mode;
Table 1-1. Scanning Speed
Original A4/Portrait A4/Portrait - A3/Portrait
Reading Area Less than 210mm 210 to 310mm
Line Art Approx. 7.5mS/line Approx. 10.8mS/line
256 Gray-scale Approx. 7.5mS/line Approx. 10.8mS/line
Full Color Approx. 10.0mS/line Approx. 15.0mS/line

GT-12000 Product Descriptions
Rev. A 1-
2
IMAGING FUNCTIONS
Gradation: Input/internal process = 12bit/pixel
Output = 8 or 12bit/pixel
Zoom: 50 to 200% (1% increment)
Gamma Correction: CRT (A/B)
PRINTER (A/B/C)
User definable (1 level)
Color Correction: Impact-Dot Printer
Thermal Printer
Ink jet Printer
CRT Display
User definable (1 level)
Brightness Control: 7 levels
Image Processing: Bi-level= Fixed threshold
TET
Half-toning= Error diffusion (A/B/C)
Dither (Resident) (A/B/C/D)
Dither (user definable) (A/B)
Focusing: One-piece CCD/Lens movement system
INTERFACE
Standard Interface: Bi-Directional Parallel
SCSI (50/50 pin connectors)
SOFTWARE
Commend Level: ESC/I-B8 (B6 level with Focus control)
ELECTRICAL SPECIFICATION
Power supply voltage: [120 V version]
Rated voltage = AC100 - 120 V (± 10%)
[220-240 V version]
Rated voltage = AC220 - 240 V (± 10%)
Rated frequency range: 50 / 60 Hz (49.5 - 60.5 Hz)
Power consumption: Approximately 60 W (without an optional unit)
Maximum 75 W (with an optional unit)
Insulation resistance: 10 M Wat 500 VDC
(between AC line and chassis)
Dielectric strength: AC 1.5 KV / minute
(between AC line and chassis)
Static electricity: Panel = 10 KV
Metal = 7 KV / 150 pF, 150 W
SAFETY, EMC
Safety regulation: UL1950 with D3
CSA C22.2 NO. 950 with D3
Low voltage directive
73/23/EEC: EN60950 (TUV)
EN60950 Nordic Deviation (NEMKO)
EMC: FCC Part15 Subpart B Class B (USA)
CSA C108.8 Class B (Canada)
AS/NZS3548 Class B
Directive 89/336/EEC: EN55022 Class B
EN61000-3-2
EN61000-3-3
EN50082-1
IEC 801-2
IEC 801-3
IEC 801-4

GT-12000 Product Descriptions
Rev. A 1-
3
ENVIRONMENTAL CONDITIONS
Temperature: Operating = 5 to 35°C
Storage = -25 to 60°C
Humidity: Operating = 10 to 80% (no condensation)
Storage = 10 to 85% (no condensation)
RELIABILITY
Main unit: MCBF 100,000 cycle
OPERATING CONDITIONS
Dust: Ordinary office or home conditions.
(Should be kept away from extreme dust.)
Illumination: Operation under direct sunlight or near
strong light source should be avoided.
DOCUMENT
Reflective type: Smooth surface such as a printing and
photograph.
Transparency type: Reversal film, Negative film
Note: The optional transparency unit must be
used.
PHYSICAL DIMENSIONS AND WEIGHT
Dimensions: 656 (W) x 458 (D) x 170 mm (H)
(See Figure 1-1.)
Weight: Approximately 20 Kg
656mm
458mm
170mm
(6.7")
(25.8")
(18")
Figure 1-1. External Dimension of the GT-12000

GT-12000 Product Descriptions
Rev. A 1-
4
1.3 INTERFACE SPECIFICATION
This scanner is equipped with the following interfaces:
q Bi-directional Parallel Interface
n Data: 8 bit parallel
n Handshake: BUSY, /ACK handshaking
n Signal: TTL level
n Connector: 36 pins (Amphenol)
q SCSI interface
n Function: Conforms to ANSI Standard X3.131-1986.
n Electrical specification:Conforms to ANSI Standard X3.131-1986.
(TTL compatible level)
n Connector: 50 / 50 pin (Amphenol)
n Terminator: Internal terminator
Switches between “active” and “ inactive”
n SCSI ID Set with an internal rotary switch
(Range: 0 - 7)

GT-12000 Product Descriptions
Rev. A 1-
5
1.4 CONTROL CODE
The command level for this scanner is ESC/I-B8. The commands
supported are shown in the table below.
Table 1-2. Control Code Summary
Category Command Name Code
Execute Command Identity Request ESC I
Status Flag Request ESC F
Extended Status Flag
Request ESC f
Parameter Request ESC S
Scanning Start ESC G
Data Format Setting Set Data Format ESC Di
Set Resolution ESC R n1 n2
Set Zooming ESC H i1 i2
Set Read Area ESC A n1 n2 n3 n4
Set Color ESC Ci
Mirroring ESC Ki
Image Setting Set Brightness ESC Li
Set Gamma Correction ESC Zi
Download Gamma Table ESC zi d0 d1 - d255
Set Sharpness ESC Qi
Image Processing Set Digital Halftoning ESC Bi
Set Auto Area
Segmentation ESC si
Download Dither Pattern ESC b I I j d (j2)
Set Color Correction ESC Mi
Download Color Correction ESC m d1 d2 - d9
Set Threshold ESC t
Table 1-3. Control Code Summary (continued)
Category Command Name Code
Auxiliary Set Scanning Mode ESC gi
Initnialize ESC @
Set Line Counter ESC di
Control Option ESC ei
Set Focus ESC pi
Focus Position Request ESC q
Set Ratio Correction for
Main and Sub Scan ESC Wi
Set the Film type ESC Ni
Eject Paper ESC FF
Feed Paper ESC PF
Control Normal Response ACK
Abnormal Response NACK
Abort Scanning CAN
Header STX

GT-12000 Product Descriptions
Rev. A 1-
6
1.5 OPERATION SPECIFICATIONS
1.5.1 Switch Specification
This scanner is equipped with 4 switches. Their functions are described
below:
q “OPERATE “
n Turns on and off the scanner.
n Pressing this switch for power-on initializes the scanner.
q “RESET”
Initializes the scanner.
q
SCSI ID rotary switch (located at the back of the scanner)
Sets the SCSI device ID for this scanner when the SCSI interface is
used to connect the scanner with the host computer.
Note: The factory default value for this scanner is “2”.
q
SCSI terminator setting switch (located at the back of the scanner)
Alternates the internal terminator setting between “Connected” and
“Disconnected” when the SCSI interface is in use.
Note: The factory default setting for this switch is “On” (Connected).
1.5.2 LED Specification
This scanner has the following 3 LED indicators:
q
OPERATE n
Indicates the scanner’s power On/Off status. It is on when the scanner
power is on.
q
READY n
n Comes on when the scanner is ready to receive commands. It
flickers during scanning due to data transmission between the host
computer and the scanner.
n Indicates an error type in combination with the ERROR LED
indicator when an error has occurred.
q
ERROR n
nn
n
Comes On when an error has occurred.
ERROR READY OPERATE RESET OPERATE
ON
OFF
SW
01
5
2
3
4
7
6
Figure 1-2. Buttons, Switches and LED Indicators

GT-12000 Product Descriptions
Rev. A 1-
7
1.5.3 Switch Setting
Among the switches equipped with this scanner, SCSI switch and the
terminator switch, which are used for SCSI interface, have the following
settings:
q SCSI-ID setting switch
ID No. Availability Note
0Available Normally assigned to other SCSI device such
as a hard disc.
1Available Normally assigned to other SCSI device such
as a hard disc.
2Available Set at the factory to the scanner.
3Available
4Available
5Available
6Available
7Available Normally assigned to the SCSI host adopter.
(Blank) Not Available Not effective / Not used
*Not Available Not effective / Not used
CHECK POINT
ü
üü
ü
Do not set the ID number that is already assigned
to other SCSI device.
q Terminator switch
Setting Note
ON Connects to the terminal resistor. /Factory default
setting
OFF Disconnects from the terminal resistor.
CHECK POINT
ü
üü
ü
Be aware that the terminator switch must be set
according to the scanner location on the “daisy-
chain”.
1.5.4 Error Indication
When an error has occurred, the error type is indicated by the
corresponding combination of the “READY” and “ERROR” LED indicators.
Table 1-4. Error Types and Corresponding Indications
READY nERROR n
nn
nError Type
ON ON Command error
OFF Blinks Communication error
Blinks Blinks Fatal error
OFF OFF Option error
Note: The remedies for these errors are provided in Chapter 3
“Troubleshooting”.

GT-12000 Product Descriptions
Rev. A 1-
8
1.5.5 Readable Area
The origin point for this scanner is marked at the rear left corner of the
document table viewed from the front. See Figure 1-3 for the maximum
readable area of the scanner.
310mm
437mm
2 ±1.5mm
2 ±1.5mm
2 ±1.5mm2 ±1.5mm
Sub Scan Direction
Main Scan Direction
Front
Origin Point
Maximum Readable Area
(12.2")
(17.2")
Figure 1-3. Maximum Readable Area
1.5.6 Transportation Screw
A transportation screw is attached to the left side of the scanner viewed
from the front. Fastening the screw fixes the CR to protect the scanner
from the shock while the scanner is transported or moved. Be sure to turn
the screw to the unlocking position (Described in the figure below.) before
turning the scanner power on.
Locking position setw hile
transporting/m oving the scanner.
U n lo c k in g p o s itio n s e t w h ile
the scanneris used.
Figure 1-4. Transportation Screw

OPERATING PRINCIPLES
CHAPTER
2

GT-12000 Operating Principles
Rev. A 2-1
2.1 GENERAL DESCRIPTION
The EPSON GT-12000 is mainly composed of the following units:
q Scanner mechanism
(Lamp/Mirror units, CR drive mechanism, integral lens/CCD sensor
unit drive mechanism)
q Control Circuit
q Power supply circuit
The EPSON flat-bed type scanners usually read images by moving the
integral CR unit which consists of the lamp, mirror, lens/CCD sensor. This
scanner, however, characteristically has the CCD sensor and the lens in
the whole unit attached onto the mechanism as an independent unit. This
scanner is also equipped with the newly designed focusing function which
enables the scanner to focus by adjusting the distance between the lens
and the CCD sensor. Therefore, the lens unit is set movable and driven by
the specified motor. Since the separate units in the mechanism such as
the lamp (light source) and the mirrors move at their own speed for
reading, the incident distance of the reflected light from the document to
the CCD sensor is kept constant.
The control circuit board and the power supply circuit board are stored in
the separate shield compartment. Since it is only connected to the
connector board in the scanner mechanism, it is removed and maintained
with ease.
B054SUB Board
CN1
CN2
CN3 CN6
CN7 CN5
CN4
B054PNL Board Motor
(for Lens Unit Drive)
Lamp/Mirror Unit Mirror Unit HP Sensor
(for Mirror)
Motor
(for Lamp/Mirror Drive)
Drive Wires
B054PSH Board
(Power Supply Circuit)
AC Input
SCSI
ID Switch
Terminator Switch
HP Sensor (Lens)
B054ISN Board
(CCD Sensor)
Lens Unit
(Optional)
I/F
B054MAIN Board
(Control Circuit)
SCSI
I/F
Bi-D
I/F
Document
Figure 2-1. Main mechanism Structure of the GT-12000