Summary of Contents for Brother PT-MT (P-touch mini ' tech
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SERVICE MANUAL MODEL: PT-MT (P-touch mini' tech)
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PREFACE This publication is a service manual covering the specifications, outline of operating principles, disassembly/reassembly procedure, and troubleshooting of the Brother PT- MT. It is intended for service personnel and other concerned persons to accurately and quickly provide after-sale service for our PT-MT.
CHAPTER I SPECIFICATIONS Mechanical Specifications 1.1.1 External Appearance Figure 1.1-1 External Appearance (1) Dimensions (W x D x H) 105 mm x 154 mm x 52 mm (2) Weight Machine proper Approx. 250 g In package Approx. 500 g (incl. a tape cassette, excl. dry cells) 1.1.2 Entry system (1) Rubber keypad...
1.1.4 Printing Mechanism (1) Print system Direct thermal printing (Fixed print head and tape feeding mechanism) (2) Print speed 7.5 mm/second (Typical) (3) Print head Type Thermal print head Heat generator Consists of 64 heating elements vertically aligned Size of a heating element 0.136 mm wide by 0.106 mm high 1.1.5 Tape Cassette...
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8 columns x 1 row Figure 1.1-2 Key Arrangement I - 3...
Electronics Specifications 1.2.1 Character Generator (1) International character German version 190 characters Other versions 182 characters (2) Internal fonts HELSINKI (3) Text buffer capacity 55 characters (4) Phrase memory capacity None 1.2.2 Power Supply (1) Power supply Driven by 6 dry cells (2) Battery type Alkaline dry cells (AM3/LR6) (3) Service life of batteries...
CHAPTER II THEORY OF OPERATION Outline of Mechanisms 2.1.1 Print Mechanism Structure of Thermal Head This machine uses direct thermal printing. The thermal print head has a heat generator consisting of 64 heating elements which are vertically aligned as shown in Figure 2.1-1. Each heating element is 0.136 mm wide by 0.106 mm high.
2.1.2 Platen Setting & Retracting Mechanism This mechanism consists of the roller holder ASSY and the roller holder setting lever (wedged lever) provided on the inside of the cassette cover. The roller holder ASSY supports the platen so that the platen can move perpendicularly to the thermal head and rotate freely.
2.1.3 Tape Feed Mechanism This mechanism consists of a DC motor, gear train and roller holder ASSY. When you load a tape cassette and close the cassette cover, the platen and the thermal head sandwich the tape inbetween and the platen gear becomes engaged with the gear train, as described in Subsection 2.1.2.
2.1.4 Tape Cutter Mechanism The cutter mechanism consists of a cutter lever and a cutter unit in which a blade is retracted by a spring. Pressing the cutter lever pushes out the blade from the cutter unit. The blade presses the printed tape against the cutter board of the tape cassette, cutting the tape coming through the cutter unit and the cutter board.
2.1.5 Cutter Safety Lock Mechanism When the cassette cover is opened and no tape cassette is loaded, the roller holder ASSY is retracted from the thermal head with the roller holder spring (as described in Subsection 2.1.2). In this retracted position, the cutter lever stopper of the roller holder ASSY blocks the end of the cutter lever, preventing the cutter lever from pushing the cutter blade out of the cutter unit for safety, as shown below.
Outline of Control Electronics 2.2.1 Configuration Figure 2.2-1 shows a block diagram of the control electronics of this machine. The control electronics consists of a main PCB, DC motor, and thermal print head ASSY. Figure 2.2-1 Configuration of the Electronic Part Main PCB This manages all the components including an LCD, DC motor, keypad, and thermal print head ASSY.
2.2.2 Main PCB Block Diagram [ 1 ] Figure 2.2-2 shows a block diagram of the main PCB. Figure 2.2-2 Block Diagram of Main PCB The main PCB consists of the following: (1) CPU (including a ROM and RAM) (2) LCD driver (3) Key contacts and solder points (4) ON/OFF key and its circuit (5) Thermal head drive circuit...
CHAPTER III DISASSEMBLY & REASSEMBLY Safety Precautions (1) You should carry out disassembly & reassembly jobs on an anti-static sheet grounded correctly. Otherwise, the LSI and other electronic devices will be damaged due to the electricity charged in your body. (2) When transporting PCBs, be sure to wrap them in conductive sheets such as aluminum foil.
Disassembly Procedure [ 1 ] Removing the Cassette Cover, Dry Cells, Tape Cassette, and Cutter Unit (1) Turn the machine upside down. (2) Press section "A" of the cassette cover to release the latch, and then remove the cassette cover. Figure 3.1-1 Removing the Cassette Cover (3) Remove six dry cells, tape cassette, and cutter unit.
[ 2 ] Removing the Chassis ASSY (1) Remove the two screws from the bottom cover. Figure 3.1-3 Unscrewing the Bottom Cover (2) Slightly open the bottom cover, discharge capacitor C5 with a screwdriver or the like, and then disconnect the head flat cable from the main PCB, as illustrated below. NOTE: Take care not to bend the head flat cable.
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(3) Unsolder the motor lead wires from the main PCB. NOTE: Do not unsolder the wires of the plus and minus terminal ASSYs. (4) Remove the three screws from the chassis ASSY. Figure 3.1-5 Unsoldering the Motor Lead Wires and Removing the Chassis ASSY (5) Lift the chassis ASSY up and out of the bottom cover.
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Disassembling the Chassis ASSY When handling the thermal head ASSY, do not touch the thermal head by hand. It may be easily damaged due to the electricity charged in your body. (1) Remove the screw from the thermal head ASSY and take off the ASSY. (2) Remove the retaining ring from the shaft of the chassis ASSY.
[ 3 ] Removing the Main PCB (1) From the battery holder side of the bottom cover, unlatch the locking pawl of each of the plus and minus terminal ASSYs with the tip of a flat screwdriver, and then push them out of the bottom cover.
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(2) Remove two screws from the main PCB. (3) While pressing the guides of the LCD flat cable outwards, slightly slide the LCD flat cable to the right and left and release it. NOTE: Take care not to bend the LCD flat cable. (4) Unlatch the LCD and take it out gently.
[ 4 ] Removing Battery Terminals P1 and P2 (1) As shown below, remove battery terminals P1 from the bottom cover with the flat screwdriver. Figure 3.1-9 Taking out Battery Terminals P1 from the Bottom Cover (2) As shown below, remove battery terminals P2 with the flat screwdriver. Figure 3.1-10 Taking out Battery Terminals P2 from the Bottom Cover III - 8...
[ 5 ] Removing the Rubber 4 Key, Lens, Dial Sheet, Select Dial, Select Dial Claw, and Enter Key (1) Remove the rubber 4 key. (2) Remove the two screws from the lens and take it out. Figure 3.1-11 Removing the Rubber 4 Key and Lens (3) Remove the three screws and take out the dial sheet.
Reassembly Procedure [ 1 ] Installing the Enter Key, Select Dial Claw, Select Dial, Dial Sheet, Lens, and Rubber 4 Key (1) Apply a rice-sized pinch of grease (Shin-Etsu Silicone G501) to each of the two lubrication points on the end of the body cover which the inside of the select dial will come into contact with, as shown below.
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(8) Secure the lens with two screws. (9) Set the rubber 4 key into place. Figure 3.2-2 Reinstalling the Rubber 4 key and Lens III - 11...
[ 3 ] Installing the Main PCB (1) Secure the main PCB to the body cover with two screws. (2) Route the LCD flat cable through the cable guides while pressing them outwards. (3) Set the LCD into place while pressing the arms outwards. Figure 3.2-5 Reinstalling the Main PCB (4) Snap each of the plus and minus terminal ASSYs into the bottom cover.
[ 4 ] Installing the Chassis ASSY (1) If the chassis ASSY has been disassembled, assemble the components, referring to page III-16. (2) As shown in Figure 3.2-10, fit the cutter lever onto the shaft on the chassis ASSY. (3) Put the chassis ASSY together with the cutter lever back into the bottom cover. NOTE: Route the head flat cable as illustrated below.
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(6) While holding the bottom cover in an angle shown below, connect the head flat cable to the main PCB. (7) Close the bottom cover. Figure 3.2-8 Connecting the Head Flat Cable (8) Secure the bottom cover to the body cover with two screws, taking care not to pinch the wires between those covers.
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Assembling the Components of the Chassis ASSY (1) Secure the DC motor ASSY to the chassis with two screws so that the motor lead wires face as shown below. (2) Set the roller holder spring onto the roller holder ASSY so that its straight end is fitted into section "A"...
[ 5 ] Setting the Cutter Unit, Tape Cassette, Dry Cells, and Cassette Cover (1) Set the cutter unit into place. (2) Set a tape cassette. (3) Load six dry cells. (4) First fit the hook of the cassette cover and then snap the cover into place. Figure 3.2-11 Setting the Cutter Unit, Tape Cassette, Dry Cells, and Cassette Cover III - 17...
[ 6 ] Final Operation Check After reassembling, do the following: (1) Load dry cells. (2) Press the ON/OFF key. (3) Turn the select dial to the desired position and press the Enter key. The selected symbol should be established. (4) Press the Print key.
[ 7 ] Inspection Mode According to the procedure given below, place the PT-MT in the inspection mode and make final operational checks. In the inspection mode, you use four submodes--INFO, DIAL, CUT, and PRINT1 submodes. TIP: The inspection mode actually supports a total of nine submodes for checking at the factory.
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INFO submode (Dial position 1 and Enter key*) (*In any other submode, setting the select dial to Dial position 1 and pressing the Enter key will jump to INFO submode, except during checking in DIAL submode.) The moment the machine enters the inspection mode, it shows "INFO," indicating that the machine is placed in INFO submode.
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2) Press the Enter key. LCD check screen 1 will appear as shown below. 3) Press the Enter key. LCD check screen 2 will appear as shown below. (All guidance indicators & cursors: ON) 4) Press the Enter key. LCD check screen 3 will appear as shown below. (All guidance indicators &...
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4) Counterclockwise turn the select dial slowly and check that the correct dial position number will be displayed. NOTE: Do not turn the select dial quickly or clockwise. Doing so cannot check the dial operation correctly. If the select dial is set to any wrong position, "X" will display as shown below.
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After feeding tape, the machine will display the following: 3) Press the Enter key. While displaying the following, the machine will feed tape. After feeding tape, the machine will display the following: 4) Press the Enter key. While displaying the following, the machine will feed tape. After feeding tape, the machine will display the following: PRINT1 submode (Dial position 4 and Enter key*) (*In any other submode, setting the select dial to Dial position 4 and pressing the Enter key...
CHAPTER IV TROUBLESHOOTING Troubleshooting This section gives the service personnel some of the troubleshooting procedures to be followed if an error or malfunction occurs with this machine. It is impossible to anticipate all of the possible troubles which may occur in future and determine the troubleshooting procedures, so this chapter covers some sample troubles.