Brother PT 1800 - P-Touch 1800 Thermal Transfer... User manual

SERVICE MANUAL
MODEL: PT-1800/1810

SERVICE MANUAL
MODEL: PT-1800/1810

© Copyright Brother 1999
All rights reserved.
No part of this publication may be reproduced in any
form or by any means without permission in writing
from the publisher.
Specifications are subject to change without notice.

PREFACE
This publication is a service manual covering the specifications, theory of operation,
disassembly/ reassembly procedure, and troubleshooting of the Brother PT-
1800/1810. It is intended for service personnel and other concerned persons to
accurately and quickly provide after-sale service for our PT-1800/1810.
To perform appropriate maintenance so that the machine is always in best condition
for the customer, the service personnel must adequately understand and apply this
manual.
This manual is made up of four chapters and appendices.
CHAPTER ISPECIFICATIONS
CHAPTER II MECHANISMS
CHAPTER III ELECTRONICS
CHAPTER IV TROUBLESHOOTING
APPENDICES CIRCUIT DIAGRAMS

CHAPTER I
SPECIFICATIONS

CONTENTS
CHAPTER ISPECIFICATIONS
1.1 MECHANICAL SPECIFICATIONS ........................................................................................I-1
1.1.1 External Appearance................................................................................................I-1
1.1.2 Keyboard..................................................................................................................I-1
1.1.3 Display......................................................................................................................I-2
1.1.4 Printing Mechanism..................................................................................................I-2
1.1.5 Tape Cassette..........................................................................................................I-3
1.1.6 Tape Cutter ..............................................................................................................I-3
1.2 ELECTRONICS SPECIFICATIONS ......................................................................................I-7
1.2.1 Character Generator ................................................................................................I-7
1.2.2 Power Supply...........................................................................................................I-7
1.3 KEY COMMANDS FOR SPECIAL FUNCTIONS...................................................................I-8
1.3.1 Initializing..................................................................................................................I-8
1.3.2 Demonstration Print..................................................................................................I-8

I- 1
1.1 MECHANICAL SPECIFICATIONS
1.1.1 External Appearance
Figure 1.1-1 External Appearance
[ 1 ] Dimensions (W x D x H) 183 x 205 x 60 mm (7.20" x 8.07" x 2.36")
[ 2 ] Weight Machine proper Approx. 730 g
In package Approx. 1.4 kg
(including batteries, a tape cassette, and user's
manual)
1.1.2 Keyboard
[ 1 ] Entry system Rubber key pad
[ 2 ] Number of alphanumeric and symbol keys 39
[ 3 ] Number of function keys 12 (including ON/OFF key)
[ 4 ] Key arrangement See Figure 1.1-2.

I- 2
1.1.3 Display
[ 1 ] Display type Liquid crystal display (LCD)
[ 2 ] Number of columns 12 columns x 2 rows
(See Figure 1.1-2.)
[ 3 ] Number of indicators 19 (See Figure 1.1-2.)
[ 4 ] Character size 5 dots wide by 7 dots high
[ 5 ] Dot size 0.524 mm (20.6 mils) wide by 0.58
mm (22.8 mils) high
[ 6 ] Field-of-view angle adjustment Fixed by a resistor
1.1.4 Printing Mechanism
[ 1 ] Print method Thermal transfer onto plastic tapes (laminate
tape and non-laminated tape) or special
tapes (instant lettering tape, non-laminated
thermal film tape, iron-on transfer tape, and
porous-stamp tape)
(Fixed print head and tape feeding
mechanism)
[ 2 ] Print speed 10 mm/second (Typical)
[ 3 ] Print head
Type Thermal print head
Heat generator Consists of 128 heating elements vertically
aligned (96 out of them actually used)
Size of heating element 0.195 mm (7.7 mils) wide by 0.141 mm (5.6
mils) high
[ 4 ] Character size (dots)
Height Point size No. of heating elements to be used
6 15
9 21
12 28
18 44
24 56
36 88
Width OFF (Medium)
ON (Wide)

I- 3
1.1.5 Tape Cassette
[ 1 ] Cassette Cartridge type
[ 2 ] Types of tape cassettes
•Laminated tape cassette Laminate tape, ink ribbon, and adhesive base
tape
•Non-laminated tape cassette Non-laminate tape and ink ribbon
•Instant lettering tape cassette Instant lettering tape and ink ribbon
•Non-laminated thermal film Non-laminated thermal film tape
tape cassette
•Iron-on transfer tape cassette Iron-on transfer tape and ink ribbon
•Stamp tape cassette Porous-stamp tape and base paper
[ 3 ] Tape size Width Length
Laminate tape 6, 9, 12, 18 mm 8 m
(5 m for the
fluorescent
coating tape)
Non-laminate tape 6, 9, 12, 18 mm 8 m
Instant lettering tape 18 mm 8 m
Non-laminated thermal film tape 12, 18 mm 8 m
Iron-on transfer tape 18 mm 6 m
Porous-stamp tape 18 mm 3 m
[ 4] Tape cassette packed with the machine
Laminated tape cassette containing a 12-mm-
wide black ink ribbon, laminate tape, and
adhesive base tape
1.1.6 Tape Cutter
[ 1 ] Tape cutting Manual cutting with the cutter lever
[ 2 ] Cutter unit Not user-replaceable

I- 4
nU.S.A/Canada
nU.K.
Figure 1.1-2 Key Arrangement (1)

I- 5
nGermany
nFrance
Figure 1.1-2 Key Arrangement (2)

I- 6
nBelgium
Figure 1.1-2 Key Arrangement (3)

I- 7
1.2 ELECTRONICS SPECIFICATIONS
1.2.1 Character Generator
[ 1 ] Internal characters U.S.A. 176
U.K./France/Belgium 197
Germany 214
[ 2] Internal fonts HELSINKI and BRUSSELS
[ 3] Print buffer capacity 99 characters
[ 4 ] Phrase memory capacity 300 characters
1.2.2 Power Supply
[ 1 ] Power supply Driven by 6 batteries
Optional AC line adapter (9.5 VDC, 1.3A)
available
[ 2 ] Battery type 6 alkaline batteries (LR6)
[ 3 ] Service life of batteries Will last through one tape cassette, and then
some. (at room temperature and normal
humidity)
[ 4 ] Automatic power off Yes
(If the machine remains unused for approx. 5
minutes, it automatically powers itself off.)
[ 5 ] Low Voltage and High-voltage input detection
(1) Low voltage detection when dry batteries are loaded:
- During printing
If the voltage level at the CPU's A/D terminals drops below 6.4 V or 6.0 V twice
in succession, the "BATTERY WEAK" or "BATTERY EMPTY" message
appears on the LCD, respectively.
If the voltage level at the CPU's A/D terminals drops below 5.8 V twice in
succession, the CPU immediately shuts down the power.
- During non-printing
If the voltage level at the CPU's A/D terminals drops below 6.9 V, the CPU
immediately shuts down the power.
(2) High-voltage input detection when a high-voltage AC adapter is connected:
If a commercially available high-voltage AC adapter (15.1 V or higher) is
connected, the CPU immediately shuts down the power.
CAUTION: A commercially available high-voltage AC adapter cannot be used
for this machine. It is recommended that a Brother genuine adapter be used.

I- 8
1.3 KEY COMMANDS FOR SPECIAL FUNCTIONS
1.3.1 Initializing
Powering on the machine with both the Code and R keys held down will initialize the
machine.
1.3.2 Demonstration Print
Pressing the D key with the Code key held down will start demonstration print. (This key
command takes effect only when no data is entered.)

CHAPTER II
MECHANISMS

CONTENTS
CHAPTER II MECHANISMS
2.1 THEORY OF OPERATION ..................................................................................................II-1
2.1.1 Print Mechanism......................................................................................................II-1
2.1.2 Platen and Tape Feed Sub Roller Setting & Retracting Mechanism.......................II-3
2.1.3 Regular Tape & Ribbon Feed Mechanism...............................................................II-4
2.1.4 Tape Cutter Mechanism..........................................................................................II-6
2.1.5 Roller Holder ASSY & Cassette Cover Interlocking Mechanism..............................II-7
2.2 DISASSEMBLY & REASSEMBLY........................................................................................II-8
2.2.1 Disassembly Procedure...........................................................................................II-8
[ 1 ] Removing the Battery Lid and Batteries..................................................................II-8
[ 2 ] Removing the Tape Cassette .................................................................................II-9
[ 3 ] Removing the Bottom Cover.................................................................................II-10
[ 4 ] Removing the Chassis ASSY................................................................................II-11
[ 5 ] Removing the Main PCB and Rubber Key Pad.....................................................II-14
[ 6 ] Removing the Cassette Sensor PCB....................................................................II-15
[ 7 ] Removing the Blind Cover ....................................................................................II-15
[ 8 ] Removing the Power Supply PCB ........................................................................II-16
[ 9 ] Removing the Battery Terminals...........................................................................II-16
2.2.2 Reassembly Procedure.........................................................................................II-17
[ 1 ] Installing the Battery Terminals.............................................................................II-17
[ 2 ] Installing the Power Supply PCB ..........................................................................II-17
[ 3 ] Installing the Blind Cover ......................................................................................II-18
[ 4 ] Installing the Cassette Sensor PCB......................................................................II-18
[ 5 ] Installing the Rubber Key Pad ..............................................................................II-19
[ 6 ] Installing the Main PCB.........................................................................................II-19
[ 7 ] Installing the Chassis ASSY..................................................................................II-20
[ 8 ] Installing the Bottom Cover...................................................................................II-23
[ 9 ] Installing the Cassette Cover................................................................................II-24
[10] Installing the Tape Cassette .................................................................................II-25
[11] Loading Batteries and Installing the Battery Lid....................................................II-25
[12] Demonstration Print and Final Check ...................................................................II-26

II - 1
2.1 THEORY OF OPERATION
2.1.1 Print Mechanism
nStructure of Thermal Head
This machine uses thermal transfer printing. The thermal print head has a heat
generator consisting of 128 heating elements (96 out of them are actually used) which
are vertically aligned as shown in Figure 2.1-1. Each heating element is 0.195 mm wide
by 0.141 mm high.
Figure 2.1-1 Heat Generator of Thermal Head
nPrinting Process
When the cylindrical rubber platen is pressed against the thermal print head with the
tape* and ink ribbon** sandwiched inbetween, the CPU applies electric power to the
selected ones of those 96 heating elements.
*Laminate tape when using laminated tape cassettes.
Non-laminated tape when using non-laminated tape cassettes.
Instant lettering tape when using instant lettering tape cassettes.
Non-laminated thermal film tape when using non-laminated thermal film tape cassettes.
Iron-on transfer tape when using iron-on transfer tape cassettes.
** When using non-laminated thermal film tape cassettes or stamp tape cassettes, no ink ribbon
is sandwiched.
[ For tape cassettes except non-laminated thermal film tape cassettes and stamp tape
cassettes ]
If the selected heating element(s) generates heat, the ink on the sandwiched ribbon will
be melted and transferred to the tape, producing a dot(s) on the tape. The ink ribbon
and the tape are advanced and then the next heating cycle is repeated, thus forming a
character on the tape.

II - 2
[ For non-laminated thermal film tape cassettes ]
If the selected heating element(s) generates heat, the thermal film tape develops itself to
produce a dot on the tape. The tape is advanced and the next heating cycle is repeated,
thus forming a character on the tape.
[ For stamp tape cassettes ]
If the selected heating element(s) generates heat, the porous-stamp tape will be melted
so that a pore (pores) will be formed in the tape. The tape is advanced and the next
heating cycle is repeated, thus forming a character of pores on the tape. The printed
stamp tape can be used as the face of a stamp. When the stamp is pressed against the
ink-pad, it will absorb ink through the pores.
For laminated tape cassettes, instant lettering tape cassettes, and iron-on transfer tape
cassettes, the CPU processes the print data to generate a mirror image so that the
printed character can be seen normally when viewed from the other side of the printed
face of the tape.
nCharacter Formation
While the drive motor (DC motor) feeds the tape and ink ribbon (only the tape when
using non-laminated thermal film tape cassettes or stamp tape cassettes) by 0.141 mm
for 13.6 ms, the thermal head generates heat once. The feed amount of 0.141 mm is
smaller than the width (0.195 mm) of the heating elements so that the heat generated at
one heating cycle will overlap with the next heating cycle. This forms a character having
no gap between adjacent printed dots.

II - 3
2.1.2 Platen and Tape Feed Sub Roller Setting & Retracting Mechanism
This mechanism consists of the roller release lever, roller release rod, and roller holder
ASSY.
The roller holder ASSY supports the platen and the sub roller holder so that:
• the platen can move perpendicularly to the thermal head and rotate freely and
• the sub roller holder can move perpendicularly to the tape feed roller.
The sub roller holder supports the tape feed sub roller so that the roller can rotate freely.
Closing the cassette cover pushes down the roller release lever which moves the roller
release rod to the left (when viewed from the front of the machine). This pivots the roller
holder ASSY around the shaft provided on the chassis so as to press the roller holder
ASSY against the thermal head.
The platen is pressed perpendicularly against the thermal head with the tape and ink
ribbon (only the tape when using non-laminated thermal film tape cassettes or stamp
tape cassettes) sandwiched inbetween under a uniform load by the platen spring. Also,
the sub roller holder is pressed so that the tape feed sub roller is pressed perpendicularly
against the tape feed roller built in the tape cassette with the tape (the laminate tape and
adhesive base tape when using laminated tape cassettes) sandwiched inbetween by the
sub roller holder springs and at the same time the tape feed sub roller's gear becomes
engaged with the tape feed gear.
Opening the cassette cover retracts the roller holder ASSY from the thermal head,
providing you with enough space to replace the tape cassette.
Figure 2.1-2 Platen and Tape Feed Sub Roller Setting & Retracting Mechanism

II - 4
2.1.3 Regular Tape & Ribbon Feed Mechanism
This mechanism consists of a drive motor, gear train, and roller holder ASSY.
nRegular Tape Feeding
When you load a tape cassette and close the cassette cover, the tape feed roller inside
the cassette and the tape feed sub roller in the roller holder ASSY sandwich the tape
(the laminate tape and adhesive base tape when using laminated tape cassettes)
inbetween, as described in Subsection 2.1.2.
As the drive motor rotates, the rotation is transmitted via the gear train to the tape feed
gear which rotates both the tape feed roller and the tape feed sub roller (whose gear is
engaged with the tape feed gear) at the same rotation speed. Accordingly, the
sandwiched tape will be advanced. (When a laminated tape cassette is mounted, the
sandwiched laminate tape and adhesive base tape will be advanced together.)
Figure 2.1-3 Tape Feeding Mechanism