Brother PT-2500PC User manual

SERVICE MANUAL
MODEL: PT-2500PC

SERVICE MANUAL
MODEL: PT-2500PC

© Copyright Brother 1998
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 label printer PT-2500PC. It is intended
for service personnel and other concerned persons to accurately and quickly provide after-sale
service for our PT-2500PC.
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 View ...........................................................................................................I-1
1.1.2 Control Buttons.........................................................................................................I-2
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
1.1.7 PC Interface .............................................................................................................I-3
1.2 ELECTRONICS SPECIFICATIONS ......................................................................................I-4
1.2.1 Power Supply...........................................................................................................I-4

I- 1
1.1 MECHANICAL SPECIFICATIONS
1.1.1 External View
(1) Dimensions (W ×D ×H) 75 mm ×232 mm ×159 mm
(2) Weight
Machine proper Approx. 1.0 kg
In package Approx. 2.4 kg
Fig. 1.1-1 External View

I- 2
1.1.2 Control Buttons
(1) Number of buttons 2 (ON/OFF ( ) and FEED/CUT ( ) buttons)
(2) Layout See Fig. 1.1-2.
Fig. 1.1-2 Layout
1.1.3 Display
(1) Display type LEDs (green/red)
1.1.4 Printing Mechanism
(1) Printing method Thermal transfer onto plastic tapes (laminate tape
and non-laminate tape) or special tapes (instant
lettering tape, non-laminate thermal film tape,
iron-on transfer tape, and porous-stamp tape)
(Fixed thermal print head and tape feed
mechanism)
(2) Printing speed 10.3 mm/sec
(3) Print head
Type Thermal print head
Heat generator Consisting of 128 heating elements vertically
aligned
Size of a heating element 0.175 mm wide by 0.127 mm high

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
- Iron-on transfer tape cassette Iron-on tape and ink ribbon
- Stamp tape cassette Porous-stamp tape and base paper
(3) Tape size
Width Length
Laminate tape 6, 9, 12, 18, 24 mm 8 m
(5 m for fluorescent
coating tapes)
Non-laminate tape 6, 9, 12, 18, 24 mm 8 m
Instant lettering tape 18 mm 8 m
Iron-on transfer tape 18 mm 8 m
Porous-stamp tape 18 mm 8 m
1.1.6 Tape Cutter
(1) Tape cutting method Automatic cutter
(Not user-replaceable)
1.1.7 PC Interface
(1) Transmission
Serial interface (RS-232C complient)
Transmission speed Max. 115200 bps
(2) Attachments
Interface cable Dedicated cable
Editor Dedicated editor

I- 4
1.2 ELECTRONICS SPECIFICATIONS
1.2.1 Power Supply
(1) Power supply Dedicated AC line adapter (9.5 VDC, 1.3A)
provided as attachment

CHAPTER II
MECHANISMS

CONTENTS
CHAPTER II MECHANISMS
2.1 THEORY OF OPERATION...............................................................................................................II-1
2.1.1 Print Mechanism .................................................................................................................II-1
2.1.2 Roller Holder ASSY Setting & Retracting Mechanism..........................................................II-3
2.1.3 Platen-head Contact Switching Mechanism According to Tape Cassete..............................II-4
2.1.4 Tape & Ribbon Feed Mechanism ........................................................................................II-5
2.1.5 Automatic Tape Cutter Mechanism......................................................................................II-7
2.1.6 Open Button........................................................................................................................II-8
2.1.7 Cassette Cover Sensor........................................................................................................II-8
2.2 DISASSEMBLY AND REASSEMBLY................................................................................................II-9
2.2.1 Disassembly Procedure.....................................................................................................II-10
[ 1 ] Removing the Tape Cassette............................................................................................II-10
[ 2 ] Removing the Front Cover and Body Cover......................................................................II-10
[ 3 ] Removing the Tape End Sensor ASSY, Sensor PCB ASSY, Cover Lock Lever,
and Open Button from the Body Cover..............................................................................II-13
[ 4 ] Removing the Cassette Cover...........................................................................................II-14
[ 5 ] Removing the Sub PCB ASSY, FEED/CUT Button, and ON/OFF Button
from the Front Cover.........................................................................................................II-16
[ 6 ] Removing the Mechanical Unit Together with the Cutter-related Components...................II-17
[ 7 ] Removing the Cutter-related Components.........................................................................II-18
[ 8 ] Removing the Roller Holder ASSY, Thermal Head Unit, and Tape Feed Motor
from the Frame ASSY.......................................................................................................II-19
[ 9 ] Removing the Main PCB ASSY and Power Supply PCB ASSY.........................................II-20
2.2.2 Reassembly Procedure .....................................................................................................II-21
[ 1 ] Installing the Main PCB ASSY and Power Supply PCB ASSY...........................................II-21
[ 2 ] Installing the Thermal Head Unit, Roller Holder ASSY, and Tape Feed Motor
onto the Frame ASSY .......................................................................................................II-22
[ 3 ] Installing the Cutter-related Components...........................................................................II-25
[ 4 ] Installing the Mechanical Unit Together with the Cutter-related Components.....................II-27
[ 5 ] Installing the ON/OFF Button, FEED/CUT Button, and Sub PCB ASSY to the Front
Cover................................................................................................................................II-28
[ 6 ] Installing the Cassette Cover.............................................................................................II-29
[ 7 ] Installing the Open Button, Cover Lock Lever, Sensor PCB ASSY,
and Tape End Sensor ASSY to the Body Cover ................................................................II-31
[ 8 ] Installing the Body Cover and Front Cover........................................................................II-33
[ 9 ] Loading a Tape Cassette...................................................................................................II-35
[ 10 ] Demonstration Print and Final Check ................................................................................II-36

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 which are vertically aligned as shown in
Fig. 2.1-1. Each heating element is 0.195 mm wide by 0.141 mm high.
Fig. 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 128 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.
Iron-on transfer tape when using iron-on transfer tape cassettes.
Porous-stamp tape when using stamp tape cassettes.
** When using non-laminated thermal film tape cassettes, no ink ribbon is sandwiched.
[ For tape cassettes except non-laminated thermal film 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.
[ 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(s) on the tape. The tape is advanced and the next heating cycle is
repeated, thus forming a character on the tape.

II - 2
[ For stamp tape cassettes ]
If the selected heating element(s) generates heat, the porous-stamp tape will be melted
so that a pore(s) will be formed in the tape. The tape is advanced and the next heating
cycle is repeated, thus forming a character of pores in 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 tape feed motor (stepping motor) feeds the tape and ink ribbon (tape only
when using non-laminated thermal film tape cassettes or stamp tape cassettes) by 0.141
mm for 5.6 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 Roller Holder ASSY Setting & Retracting Mechanism
This mechanism consists of the release lever, release rod, and roller holder ASSY.
The roller holder ASSY incorporates the platen holder and the sub roller holder. These
holders support the platen and the tape feed sub roller so that they can move
perpendicularly to the thermal head and the tape feed roller, respectively, as well as
rotating freely.
Loading a tape cassette and closing the cassette cover pushes down the release lever
which moves the 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 side.
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. At the
same time, the platen gear becomes engaged with the platen idle gear.
Also, the tape feed sub roller is pressed perpendicularly against the tape feed roller built
in the tape cassette with the tape (and base paper when using laminated tape cassettes
or stamp tape cassettes) sandwiched inbetween under a uniform load by the sub roller
holder springs. At the same time, the sub roller gear becomes engaged with the tape
feed gear.
If you open the cassette cover, the release lever pops up by pivoting around its center
shaft since its bottom end is pulled down by the release lever spring. This retracts the
roller holder ASSY from the thermal head, providing you with enough space to replace
the tape cassette.
Fig. 2.1-2 Roller Holder ASSY Setting & Retracting Mechanism

II - 4
2.1.3 Platen-head Contact Switching Mechanism According to Tape Cassette
This mechanism consists of the cassette rod, release lever, and release rod.
As described in Subsection 2.1.2, loading a tape cassette and closing the cassette cover
pushes down the release lever which presses the roller holder ASSY against the thermal
head. If the roller holder ASSY is kept pressed against the thermal head for a long time,
however, the platen could be deformed. To avoid it, this mechanism switches the pivot
angle of the roller holder ASSY so that the roller holder ASSY does not come into contact
with the thermal head when no tape cassette is loaded.
If you load a tape cassette, the cassette edge presses the cassette rod to turn it
clockwise (when viewed from the top). Engaged with the cassette rod, the release lever
tilts ("A" in the illustration below) so that closing the cassette cover presses the release
lever at the lower end of box "X." Accordingly, the roller holder ASSY pivots at a great
angle, pressing the platen against the thermal head.
If no tape cassette is loaded, the release lever stands straight ("B"). When you close the
cassette cover, the release lever comes into box "X." so that the roller holder ASSY
pivots at a slight angle, preventing the platen from coming into contact with the thermal
head.
When a tape cassette is loaded
When no tape cassette is loaded
Fig. 2.1-3 Platen-head Contact Switching Mechanism According to Tape Cassette

II - 5
2.1.4 Tape & Ribbon Feed Mechanism
This mechanism consists of a tape feed motor, gear train, and roller holder ASSY.
nTape Feeding
When you load a tape cassette and close the cassette cover, the platen and the thermal
head sandwich the tape and ink ribbon (only the tape when using non-laminated thermal
file tape cassettes or stamp tape cassettes) inbetween. Also, the tape feed sub roller in
the roller holder ASSY and the tape feed roller inside the tape cassette sandwich the
tape (and base paper when using laminated tape cassettes or stamp tape cassettes)
inbetween, as described in Subsection 2.1.2.
As the tape feed motor (stepping motor) rotates, the rotation is transmitted via the gear
train to the platen idle gear (which rotates the platen gear) and the tape feed gear (which
rotates the tape feed roller and the tape feed sub roller at the same rotation speed).
Accordingly, the sandwiched tape and ink ribbon will be advanced. (When a laminated
tape cassette is mounted, the sandwiched laminate tape, adhesive base tape, and ink
ribbon will be advanced together).
The feeding amount of the platen is slightly less than that of the tape feed sub roller.
Fig. 2.1-4 Tape Feeding Mechanism

II - 6
nAdhesive Base Tape Feeding (only for laminated tape cassettes)
A laminated tape cassette contains both a transparent laminate tape roll and a separate
adhesive base tape roll.
When a transparent laminate tape and an adhesive base tape pass through the contact
point (between the tape feed roller and tape feed sub roller), they are then bonded
together into a single, printed tape. The ink printed on the laminate tape is, therefore,
sealed up with the adhesive base tape.
nInk Ribbon Feeding (except for non-laminated thermal film tape cassettes and stamp
tape cassettes)
As the tape feed motor rotates, the ribbon drive cam located at the middle of the gear
train rotates counterclockwise. When fitted on the ribbon drive cam, the ribbon take-up
roll in the tape cassette also rotates to take up the ink ribbon.
To apply proper tension to the ink ribbon between the platen and the ribbon drive cam,
the feed amount of the ribbon drive cam is slightly greater than that of the tape feed
gear. The difference between the feed speeds at the platen and at the ribbon drive cam
is absorbed by the clutch spring which is integrated in the ribbon drive cam and allows
the cam to slip.
This way, the ink ribbon is kept tense, which enables the ribbon to clearly separate from
the tape at the stabilized angle after printing.
Fig. 2.1-5 Ribbon Feeding Mechanism

II - 7
2.1.5 Automatic Tape Cutter Mechanism
The tape cutter unit consists of a stationary blade and a movable blade driven by the
cutter motor.
Upon completion of printing and tape feeding, the CPU activates the cutter motor (DC
motor) whose clockwise rotation is transmitted via the idle gears to the cutter moving
gear.
As the cutter moving gear rotates counterclockwise, its boss "X" (which is fitted in the
opening of the movable blade) actuates the movable blade to pivot it around shaft "Y."
Consequently, the cutter cuts the printed tape routing through the movable and
stationary blades, just like a scissors.
After that, the CPU keeps the cutter motor on. When the movable blade comes back to
the home position, its end "Z" activates the cutter sensor actuator which presses the
cutter sensor switch. The moment the CPU receives the sensor signal, it stops the cutter
motor.
Fig. 2.1-6 Automatic Tape Cutter Mechanism

II - 8
2.1.6 Open Button
Sliding the open button turns the cover lock lever as illustrated below, releasing the
cassette cover.
Fig. 2.1-7 Open Button
2.1.7 Cassette Cover Sensor
The cassette cover sensor is provided on the sensor PCB. If you close the cassette
cover, its sensor tab pushes down the sensor, signaling that the cassette cover is closed.
Fig. 2.1-8 Cassette Cover Sensor