SERVICE MANUAL. MODEL:PT-100 (For U.S.A. / Canada)

Transcription

1 R SERVICE MAUAL MODEL:PT-100 (For U.S.A. / Canada)

2 R SERVICE MAUAL MODEL: PT-100 (For U.S.A. / Canada)

3 Copyright Brother 1995 All rights reserved. o 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.

4 PREFACE This publication is a service manual covering the specifications, theory of operation, disassembly/reassembly procedure, and troubleshooting of the Brother PT-100. It is intended for service personnel and other concerned persons to accurately and quickly provide after-sale service for our PT-100. 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 three chapters and appendix. CHAPTER I. CHAPTER II. CHAPTER III. SPECIFICATIOS MECHAISMS ELECTROICS APPEDIX CIRCUIT DIAGRAM

5 CHAPTER I. SPECIFICATIOS

6 COTETS 1.1 MECHAICAL SPECIFICATIOS...I External Appearance...I Keyboard...I Display...I Printing Mechanism...I Tape Cassette...I Tape Cutter...I ELECTROICS SPECIFICATIOS...I Character Generator...I Power Supply...I-4

7 1.1 MECHAICAL SPECIFICATIOS External Appearance 53.6 mm mm mm Fig External Appearance (1) Dimensions (W x D x H) x x 53.6 mm (2) Weight Machine proper only In package Approx. 400 g 700 g or less (including the machine, packing materials and packaged standard components) Keyboard (1) Entry system Rubber 50 key (2) umber of alphanumeric 42 and symbol keys (3) umber of function keys 8 (including O key/off key) (4) Key arrangement See Fig Display (1) Display type Light emitting diode (LED) (2) umber of LEDs 2 (See Fig ) I - 1

8 1.1.4 Printing Mechanism (1) Print method Thermal destruction method, orthodox printing to the thermal destruction tape (Fixed print head and tape feeding mechanism) (2) Print speed 7.5 mm/second (Typical) (3) Print head Type Heat generator Size of heating element Thermal print head Consists of 64 heating elements vertically aligned mm wide by mm high (4) Character size (dots) Width x Height Standard (Large) size (4) 64 x 40 Small size (1) 32 x Tape Cassette (1) Cassette Cartridge type (2) Type of tape cassette Thermal destruction tape (3) Tape size Width: 9, 12 mm Length: 8 m (4) Tape cassette packed with es (to be attached to the machine) the machine Character color: Black Tape color: Silver Tape width: 9 mm Tape Cutter (1) Tape cutting Manual cutting with the cutter lever (2) Cutter unit User-replaceable I - 2

9 POWER ETER POWER ETER PRIT LARGE FEED SMALL % $ CLEAR DEL OFF O PRIT LARGE FEED SMALL % $ CLEAR DEL OFF O ORM. BOLD OUTL SHADOW FRAME ' 1 = & 9 ORM. BOLD OUTL SHADOW FRAME ' 1 = & # 6! 8? # 6! 8 0 Q E T U O?! Â Q Ê E Î T Û U Ô O ç Æ W R I P À W È R Ù Ë I É P A D G J L : ; A D G Ï J Ö L : ; CODE S F H K Z C B M ç Ñ, CODE S F H K Z C B M?., SHIFT X V SPACE SHIFT X V SPACE US CAADA Fig Key Arrangement I - 3

10 1.2 ELECTROICS SPECIFICATIOS Character Generator (1) Internal characters US: 59 Canada: 69 (2) Internal font HELSIKI (3) Print buffer capacity 55 characters (4) Phrase memory capacity one Power Supply (1) Power supply Driven by 6 batteries (2) Battery type 6 alkaline batteries (AM3/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 es (If the machine remains unused for approx. 5 minutes, it automatically powers itself off.) (5) Battery indication 1) If the voltage is detected less than 6.8V when power is on, the battery is assumed to be reverse positioned, and power is off. 2) If the voltage is detected less than 5.9V during printing, the battery is assumed to be weak and the LED display performs upon the completion of printing. 3) If the voltage is detected less than 5.1V during printing, it is assumed to be system off level and power is off. I - 4

11 CHAPTER II. MECHAISMS

12 COTETS 2.1 THEOR OF OPERATIO...II Print Mechanism...II Platen Setting & Retracting Mechanism...II Tape Feed Mechanism...II Tape Cutter Mechanism...II Interlock Mechanism of the Roller Holder and the Cassette Cover...II DISASSEMBL & REASSEMBL...II Disassembly Procedure...II-6 [1] Removing the battery lid and batteries...ii-6 [2] Removing the tape cassette and cutter unit... II-7 [3] Removing the bottom cover... II-8 [4] Removing the motor holder assy... II-9 [5] Removing the main (control) PCB and rubber 50 key...ii-11 [6] Removing the battery terminals... II Reassembly Procedure...II-13 [1] Installing the battery terminals...ii-13 [2] Installing the rubber 50 key... II-13 [3] Installing the main (control) PCB...II-13 [4] Installing the motor holder assy...ii-14 [5] Installing the bottom cover... II-16 [6] Installing the tape cassette and cutter unit...ii-17 [7] Installing the cassette cover... II-17 [8] Loading the batteries and installing the battery lid...ii-18 [9] Demonstration print and final check...ii TROUBLESHOOTIG...II Precautions...II After Repairing...II Troubleshooting Flows...II-20 [1] Tape feeding failure... II-20 [2] Printing failure... II-22 [3] Powering failure (othing appears on the LED.)...II-24 [4] o key entry possible... II-25

13 2.1 THEOR OF OPERATIO Print Mechanism (1) Structure of thermal head This machine uses thermal destruction method. The thermal print head has a heat generator consisting of 64 heating elements which are vertically aligned as shown in Fig Each heating element is mm wide by mm high mm mm mm Fig Heat Generator of Thermal Head (2) Printing process As a voltage is selectively applied to the 64-divided heating elements of the thermal head when the thermal head is pressed to the cylindrical rubber platen between the thermal destruction tape, the metal deposition layer of the thermal destruction tape is dissolved due to heat generated from the heating elements and the substrata layer appears. At this time, the thermal destruction tape is transferred. As the pressed part with the thermal head moves, the character is formed on the thermal destruction tape and printing is completed. (3) Character formation While the drive motor (DC motor) feeds the tape by mm for 13.8 ms, the thermal head generates heat once. The feed amount of mm is smaller than the width (0.136 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 - 1

14 2.1.2 Platen Setting & Retracting Mechanism This mechanism consists of the roller release lever and roller holder assy. The roller holder assy supports the platen so that the platen can move perpendicularly to the thermal head and rotate freely. Closing the cassette cover pushes down the roller release lever. This pivots the roller holder assy around the shaft provided on the motor holder and the stopper of the roller holder moves so that the stopper comes into contact with the head holder so as to press the roller holder assy towards the thermal head side. The platen is pressed perpendicularly against the thermal head with the tape sandwiched inbetween under a uniform load by the platen spring. At this time, the platen gear is engaged with the gear on the frame side to enable tape feed. Opening the cassette cover retracts the roller holder assy from the thermal head, providing you with enough space to replace the tape cassette. Motor holder Tape cassette Thermal head Platen Roller release lever Release lever spring Stopper Tape Shaft Roller holder assy Roller holder spring Platen spring Platen Platen gear Stopper Fig Platen Setting & Retracting Mechanism II - 2

15 2.1.3 Tape Feed Mechanism Tape cassette Thermal head assy Platen gear Frame gear Printing surface Tape Roller holder assy Motor holder Release lever spring Roller release lever DC motor Fig Tape Feed Mechanism When the tape cassette is set and the cassette cover is closed, the platen permits the tape to be pressed on the thermal head. At this time, the platen gear is engaged with the frame gear. The gear side and platen are rotated by rotation of the tape feed motor (DC motor). The platen is rotated to feed the tape pressed to the platen by the set distance. II - 3

16 2.1.4 Tape Cutter Mechanism The printed tape is sent from the tape cassette. The cutter unit consists of a cutter case and a cutter holder on which a cutter blade is mounted. Pressing the cutter lever, the cutter holder is pressed to the cutter lever, the cutter blade is pressed to the cutter board of tape cassette, and the tape between cutter blade and tape cassette is cut. Cutter lever Cutter unit Tape Tape cassette Fig Tape Cutter Mechanism II - 4

17 2.1.5 Interlock Mechanism of the Roller Holder and the Cassette Cover When the cassette cover is closed, the roller release lever is pressed by the cassette cover, the release lever spring is pulled, the roller holder rotates, and the stopper of the roller holder is pressed to the heat sink. At this time, the rotation of the roller release lever is increased by the frequency at which the stopper comes into contact with the heat sink surely. When the cassette cover is opened, the roller release lever is returned by the release lever spring and the roller holder is returned to the release position by the roller holder spring. Roller release lever Release lever spring Fig Interlock Mechanism of the Roller Holder and the Cassette Cover (1) Roller holder assy Stopper Roller holder spring Roller release lever Release lever spring Heat sink Fig Interlock Mechanism of the Roller Holder and the Cassette Cover (2) Cassette cover Roller holder Roller release lever Fig Interlock Mechanism of the Roller Holder and the Cassette Cover (3) II - 5

18 2.2 DISASSEMBL & REASSEMBL Disassembly Procedure [1] Removing the battery lid and batteries (1) Turn the machine upside down. (2) Press section A of the battery lid to remove, then take out batteries. Battery lid Section A Batteries Fig Removing Batteries II - 6

19 [2] Removing the tape cassette and cutter unit (1) Place the machine upside down and remove the cassette cover. (2) Pull the tape cassette up and out of the machine with pushing the section A. (3) Remove the cutter unit. Cassette cover Section A Tape cassette Cutter unit Fig Removing the Tape Cassette and Cutter Unit II - 7

20 [3] Removing the bottom cover (1) Place the machine upside down. (2) Remove the two screws. (3) Disengage the four hooks, then the bottom cover and upper cover is separated. And pull up the bottom cover. Bottom cover Hook Screw Hook Screw Hook Upper cover Hook Fig Removing the Bottom Cover (1) (4) Open the bottom cover to the left as shown below. (5) Disconnect the battery harness connector, motor harness connector and thermal head flat cable from the main (control) PCB. Bottom cover Battery harness connector Motor harness connector Thermal head flat cable Main PCB Fig Removing the Bottom Cover (2) II - 8

21 [4] Removing the motor holder assy (1) Remove the three screws. (2) Lift the motor holder assy up and out of the bottom cover. (3) Remove the cutter lever. Screws Motor holder assy Shaft Bottom cover Cutter lever hole Cutter lever Fig Removing the Motor Holder Assy II - 9

22 Disassembling the motor holder assy (1) Remove the retaining ring from the motor holder assy. (2) Push the roller release lever down as shown below and remove it from the motor holder. Pull up the roller holder assy together with the roller release lever, release lever spring and the roller holder spring from the motor holder assy. (3) Remove the screw and take off the thermal head assy. (4) Remove the two screws and take off the DC motor assy. Retaining ring Roller holder assy Release lever spring Roller holder spring Roller release lever Screw DC motor assy Thermal head assy Motor holder assy Screws Fig Disassembling the Motor Holder Assy II - 10

23 [5] Removing the main (control) PCB and rubber 50 key (1) Remove the two screws. (2) Before handling the main PCB, touch a metal portion of the machine to discharge static electricity, or the LSI and other electronic devices may be damaged due to the electricity charged in your body. Screws Main PCB Upper cover Fig Removing the Main PCB Main PCB Rubber 50 key Upper cover Fig Removing the Rubber 50 Key II - 11

24 [6] Removing the battery terminals (1) Remove the negative (-) battery terminal from the top of the bottom cover shown in Fig (2) As shown in Fig and Fig , turn the bottom cover upside down and remove the other (±) battery terminals P2, P1 while slightly bending section A after remove the hooks with a small minus screwdriver. (3) Remove the positive (+) battery terminal from the bottom cover shown in Fig (±) Battery terminals P2 1 2 Bottom cover 3 Section A Fig Removing the Battery Terminals (1) Bottom cover Positive (+) battery terminal (±) Battery terminals P1 egative (-) battery terminal Fig Removing the Battery Terminals (2) II - 12

25 2.2.2 Reassembly Procedure [1] Installing the battery terminals (1) Turn the bottom cover upside down and fit the positive (+) battery terminal of battery harness assy into the bottom cover. (2) Put two (±) battery terminals P1 into the bottom cover from same direction. (3) Fit the negative (-) battery terminal of battery harness assy last. (4) Put three (±) battery terminals P2 into the bottom cover in the direction of arrow. ote: When installing the battery terminals, set them into the grooves certainly. Make sure to fit the all terminals completely. (±) Battery terminals P2 Bottom cover Positive (+) battery terminal Battery harness Bottom cover (±) Battery terminals P1 egative (-) battery terminal Fig Installing the Battery Terminals [2] Installing the rubber 50 key (1) Place the rubber 50 key so that it is fitted over the pins provided on the upper cover. Screws Main PCB Pin Rubber 50 key Upper cover placed upside down Pin Pin Fig Installing the Rubber 50 key [3] Installing the main (control) PCB (1) Check that there is no foreign material or dust on the key contacts on the main PCB, then install the PCB. (Refer to Fig ) (2) Tighten two screws securing the PCB. II - 13

26 [4] Installing the motor holder assy (1) Fit the cutter lever into the bottom cover in the order of the numbers shown in Fig Bottom cover 2 Cutter lever 1 Fig Installing the Cutter Lever (2) If the motor holder assy has been disassembled, assemble the components by referring to the next page. (3) Install the motor holder assy onto the bottom cover with passing the shaft on the motor holder through the cutter lever hole. (4) Locate two pins of bottom cover and secure three screws. Screws Motor holder assy Shaft Locating and securing holes Bottom cover Pin Cutter lever hole Cutter lever Pin Fig Installing the Motor Holder Assy II - 14

27 Assembling the components of the motor holder assy (1) Install the DC motor assy to the motor holder assy with two screws. (2) Install the thermal head assy with a screw. (3) Set the roller holder spring and release lever spring into the roller holder assy, then hold the other tip of release lever spring to the roller release lever and install them to the motor holder assy. ote: For easier installation, assemble the roller release lever in an angle shown below. (4) Set the retaining ring to the motor holder assy. Retaining ring Roller holder assy Release lever spring Roller release lever Roller holder spring DC motor assy Screw Thermal head assy Motor holder assy Screws Roller holder spring Fig Assembling the Components of the Motor Holder Assy II - 15

28 [5] Installing the bottom cover (1) Hold the bottom cover as shown below and connect the battery harness connector, the motor harness connector and thermal head flat cable to the main PCB. And set the only battery harness to the groove. (2) Put the upper cover and the bottom cover together by setting four hooks. ote: Take care not to pinch the cords between those covers and put the cords on the condenser. Hook Bottom cover Motor harness Battery harness Battery harness Hook Thermal head flat cable Battery harness connector Motor harness connector Hooks Groove Fig Installing the Bottom Cover (1) (3) Secure the bottom cover with two screws. Bottom cover Screw Screw Fig Installing the Bottom Cover (2) II - 16

29 [6] Installing the tape cassette and cutter unit (1) Load the tape cassette. (2) Put out the cutter lever and install the cutter unit. Tape cassette Cutter unit Cutter lever Fig Installing the Tape Cassette and Cutter Unit [7] Installing the cassette cover (1) Fit the cassette cover and push down the cover with pushing section A. Cassette cover Section A Fig Installing the Cassette Cover II - 17

30 [8] Loading the batteries and installing the battery lid (1) Load batteries. (2) Fit the rear end of the battery lid into the bottom cover and push down the lid with pushing section A. Battery lid Section A Batteries Bottom cover Fig Loading the Batteries and Installing the Battery Lid [9] Demonstration print and final check (1) Press the O key. (2) While holding down the CODE key, press the DEL key to cancel data previously entered. (3) While holding down the CODE key, press the D key to start the demonstration print. (4) During the demonstration print, check that the machine feeds the tape and prints data correctly. Then, cut the tape. If any problem is found, go to the troubleshooting in Section 2.3. (5) Open the cassette cover to check that it retracts the roller holder assy from the thermal head. Close the cassette cover to check that it presses the roller holder assy against the thermal head. (6) Check that pressing the keys causes correct operation. (7) Check that the O key/off key operates correctly. II - 18

31 2.3 TROUBLESHOOTIG This section gives the service personnel some of the troubleshooting procedures to be followed if an error or malfunction occurs with the PT-100. 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. However, those samples will help service personnel pinpoint and repair other defective elements if he/she analyzes and examines them well Precautions Be sure to observe the following precautions to prevent the secondary problems from happening during troubleshooting: (1) Get a good idea of what the trouble is. Whenever more than one trouble source is found, plan the most reasonable repairing procedure after reviewing the relationship between them. (2) When supplying power to the PT-100 having problems from either a set of batteries, make sure that its output voltage level is 8 to 10V under no load. (3) When supplying power from a stabilized power unit, use the power unit with approx. 3A capacity and choose the output level of 7 to 9V. When connecting it to the PT-100, be careful with the polarity. (4) When using a circuit tester for testing the conductivity, remove all of the batteries from the PT-100. (5) To repair an error which occurred in the thermal print head and its related sections, disconnect the thermal head cable until repairs are finished After Repairing After repairing the defective section, be sure to check again to see if the repaired section works correctly. Also make a note of the troubleshooting procedure so that it will be handy should problems occur in the future. II - 19

32 2.3.3 Troubleshooting Flows [1] Tape feeding failure The tape will not feed through. Put in a new tape cassette, then try printing again. ormal tape feeding? End of repair. The old tape cassette may be defective. Is there any oil on the platen roller? Clean up the platen roller. Is the pressure of the tape feed platen roller 410±50g at the roller center? Replace the roller holder assy. When the roller release lever is pushed down, the stopper of roller holder fit the head holder? Replace the release lever spring. Any DC motor rotation? Without tape cassette loaded and with the roller release lever pushed down, normal DC motor rotation? Is the motor connection correct? Any open circuit in the motor harness? Correct it. Replace the motor harness with a new one. Is the platen roller gear deformed? With tape cassette loaded and with the roller release lever pushed down, normal DC motor rotation? C (in CHAPTER III, Subsection 3.3.3, [1].) Replace the roller holder assy. A B II - 20

33 A B Is the black rubber on the platen roller deformed or the black rubber on the platen roller slip against the shaft? Replace the roller holder assy. Replace the batteries with new ones. ormal tape feeding? End of repair. Print pitch (printed character width) is normal? Are the motor gear or any other drive gears deformed or loose? Replace the motor holder assy. Replace the DC motor. ormal tape feeding? C (in CHAPTER III, Subsection 3.3.3, [1].) II - 21

34 [2] Printing failure The tape is fed normally but no printing occurs. Is the thermal head cable connection correct? Correct it Are certain dot(s) always missing? The thermal print head may be partially clogged. Clean it up. Is the total width of printed characters normal? The tape feeding may be abnormal. Replace the batteries. If the problem persists, go to the troubleshooting flow [1]. Any vertical gaps in printed characters (dot shifting)? Lesson the backlash between the motor gear and the mating gear. Any dots missing immediately after tape cassette loading? After loading a tape cassette, press the FEED key to feed the tape. D D II - 22

35 D Any faintly printed characters? Replace the batteries. Check that the platen is set into place and works normally. If the printed characters become faint in cycles, the gear of platen roller in the roller holder assy may be deformed. Replace the roller holder assy. Check that the center of the thermal print head is within +0.3, -0.1 mm from the platen center. If it is shifted greatly, loosen the screw on the thermal head assy and adjust the assy. Head surface Thermal head assy Stopper +0.3, -0.1 Platen Platen center Any horizontal streaks in printed characters? Replace the tape cassette. Check that there is no dust on the platen or the thermal print head. ormal printing? End of repair. E (in CHAPTER III, Subsection 3.3.3, [2].) II - 23

36 [3] Powering failure (othing appears on the LED.) Turning on the O key does not power the machine; nothing appears on the LED. Are the batteries loaded with right polarity? Correct the loading direction of those batteries. Any breaks in the battery power cords? Replace the battery harness. Replace the batteries with new ones and turn on the O key/off key. Power supplied? End of repair. F (in CHAPTER III, Subsection 3.3.3, [3].) II - 24

37 [4] o key entry possible o key entry is possible Any dust or foreign material on the key contacts? Clean the key contacts or replace the key pad. G (in CHAPTER III, Subsection 3.3.3, [5].) II - 25

38 CHAPTER III. ELECTROICS

39 COTETS 3.1 OVERVIEW...III Configuration of the Electronic Part...III Main (Control) PCB... III Motor... III Thermal Head... III MAI (COTROL) PCB... III Main PCB Block Diagram...III Keyboard and Solder Point...III O Key/OFF Key and Reset Circuit...III Motor Drive Circuit and Voltage Detection Circuit...III Thermal Head Control Circuit...III Oscillation Circuit... III Buzzer Circuit... III LED Drive Circuit...III V Power Supply Circuit... III TROUBLESHOOTIG... III Precautions... III After Repairing... III Troubleshooting Flows... III-14 [1] Tape feeding failure...iii-14 [2] Printing failure...iii-14 [3] Powering failure (Red LED is not turn on.)...iii-15 [4] Abnormal LED indication...iii-16 [5] o key entry possible...iii-16 [6] Abnormal buzzer...iii-17

40 3.1 OVERVIEW Configuration of the Electronic Part Fig shows the configuration of the electronic part. This part consists of a PCB, a motor and a thermal head Main (Control) PCB This PCB assures management of all operations of LEDs, motor, keyboard, thermal head, etc Motor The motor functions as a tape feeder, which is a DC motor Thermal Head The thermal head is a thick film thermal print head with a built-in driver circuit, composing of 64 x 1 dots. egative battery terminal Positive battery terminal P1 LED Key contacts Motor P2 P3 Main PCB Thermal head Fig Configuration of the Electronic Part III - 1

41 3.2 MAI (COTROL) PCB Main PCB Block Diagram Fig shows the main PCB block diagram. Motor Motor drive circuit LED circuit Thermal head Voltage detection circuit 5V power supply circuit CPU M38062M3 #1 OFF key Oscillation circuit Keyboard Reset circuit O key Fig Main PCB Block Diagram Main PCB consists of the CPU, LED circuit, keyboard, motor drive circuit, reset circuit O key/ OFF key, voltage detection circuit and oscillation circuit as shown in Fig (1) CPU The CPU is a 8 bit microcomputer that incorporates the CMOS silicone gate process with a 12 Kbyte ROM and a 384 byte RAM and controls and supervises the entire system. (2) LED circuit This circuit serves to light two LEDs, red and green. (3) Keyboard 48 key contact patterns are laid out on a matrix on the main PCB, and knows key input. (4) Motor drive circuit This circuit controls O/OFF operation for motor feeding a tape by CPU control. It also controls O/OFF operation of the voltage detection circuit. III - 2

42 (5) Reset circuit This circuit serves to generate a signal for starting up the CPU. (6) O key/off key These keys are separately provided as two independent keys. O key is connected to the reset circuit, and OFF key is connected to the CPU interrupt input terminal. (7) Oscillation circuit This circuit performs 8.00 MHz oscillation for the CPU. (8) Voltage detection circuit This circuit transmits the battery voltage to the CPU, and the voltage values is determined by the CPU. The following describes the details Keyboard and Solder Point Rubber spring Conductive paints Patterned electrode (carbon print) PCB Fig Detailed Diagram of Keyboard Fig shows the detailed diagram of keyboard. The rubber spring is made of a high insulating silicone rubber, has a conductive paints inside of the spring. A paired pattern electrode for a key is patterned on the main PCB, and pressing the key permits electrical connection of the pattern electrodes on the main PCB by conductive paints. Fig shows the matrix diagram of keyboard. III - 3

43 Z D E 3 4 R F X (CAADA) CODE A Q 1 2 W S SHIFT C B M, G J L : T U O C PRIT I P FEED H K? $ V SPACE DEL 64 CPU M38062M3 #1 P30 Z CODE C B M, D A G J L : E Q T U O? PRIT R W I P FEED F S H K C $ X SHIFT V SPACE DEL (US) P81 P82 P83 P84 P85 P86 A E B C F G D H Solder point P87 P07 Solder point 1 57 P P70 P71 P72 P73 P74 P75 P76 P77 Fig Matrix Diagram of Keyboard III - 4

44 10 ms P77 1 ms P76 P µs 130 µs P µs Fig Key Scan Output Waveforms (1) Key scan Key scan is performed with 48 keys excluding the O key/off key. P70~P77 of CPU serve as the scan output ports, P81~P86 serve as the input ports for 48 key inputs, and P87 and P07 serve as the input ports for the solder points. Fig shows the P70~P77 key scan output waveforms. The outputs enter L in order of P77, P76, P75, P74, P73, P72, P71, and P70, the other outputs enter high impedance. At the time of L, enter the P81~P86 states. Key scan is performed during the period of 10 ms. When two continuous O inputs are read, that key is confirmed as O. And when six continuous OFF inputs are read, that key is confirmed as OFF. Further, when three or more key inputs are recognized during a single cycle key scan, all the key inputs in that cycle are assumed to be invalid (2 key roll-over processing). (2) Solder point The solder points (A~F) in the key scan circuit are provided to determine the conductive time for the thermal head. The conductive time is determined by soldering at the solder points A ~F. This is not currently used. Solder point 1 is switched according to national specifications. The solder point at which soldering is not performed is included in the US specifications. Alternatively, the solder point at which soldering is performed is included in the Canadian specifications. III - 5

45 3.2.3 O Key/OFF Key and Reset Circuit (1) O key/off key Vcc +5V OFF key R8 100K 24 M38062M3 #1 IT1 (P43) RESET 27 R9 470 R6 220K ±0V C3 105 O key Fig O Key/OFF Key ±0V O key/off key are provided on the keyboard and completely differ from the other keys in input processing. 1) OFF to O O key pressed O key released ~ 2 The CPU is inactive while O key is pressed. ~ 3 Time length of reset is extended by the reset circuit. 3 The reset signal is cancel and a program is started. III - 6

46 2) O to OFF OFF key pressed OFF key released 10 ms To sleep process module by interrupt. (IT1 input) OFF key input is recognized when P43 is L, and processing goes to main process. When P43 is H, it is assumed to be noise and the key remains in O status. (2) O/OFF operation and sleep mode O operation makes red LED turned on, buzzer beeped, and keyboard input possible. OFF operation makes buzzer beeped and red LED turned off. The CPU stops the oscillation clock and enters low power consumption mode (sleep mode). (3) Automatic power off If there is no key input for about 5 minutes, the CPU stops the oscillation clock and enters low power consumption mode (sleep mode). The automatic power off is cancelled by pressing the O key. III - 7

47 3.2.4 Motor Drive Circuit and Voltage Detection Circuit Motor M VBT R1 5.6K ±0.5% R4 4.3K ±0.5% 76 P67 #1 CPU Q1 B1427 ±0V R3 180 R2 1K ±0V Q3 DTC114K 47K 10K P41 28 P2 ±0V Fig Motor Drive Circuit and Voltage Detection Circuit Fig shows the motor drive circuit and voltage detection circuit. This motor is used to feed a tape. P41 port of the CPU outputs the start/stop signal. Fig shows the part of motor waveforms. This circuit divides VBT, the voltage of batteries, and sent to P67, the analog input port of the CPU for detection. (1) If the voltage is less than approx. 6.8V when power is on, power supply is forced to be off. (2) If the voltage is less than approx. 5.9V in printing, the sign indicating short of capacity of the batteries appears. And if the voltage is less than approx. 5.1V, power supply is forced to be off at that point. Print start Motor start 4 Motor stop CPU port P41 Reference values: Motor current ~700 ma 30~100 ma 40~70 ms Approx. 200 ms Fig Part of Motor Waveforms III - 8

48 3.2.5 Thermal Head Control Circuit Fig shows the thermal head control circuit. The thermal head consists of 64 heating elements (64 dots, 240 dpi). The driver IC is built-in. The serial data is output from P45 in synchronization with P46 clock of the CPU. As one output, 8 sets of 8 bit data, a total of 64 dots, are sent to the thermal head. CPU #1 P45 P46 P47 P50 P51 P C4 105 R7 1M R5 470 R VBT C V VH DATA CLOCK LATCH/ VDD GDH GDL STROBE/ B. E. O VBT 10 VH Fig Thermal Head Control Circuit P3 (HEAD) P45 (DATA) P46 (CLOCK) P47 (LATCH) P50 (VDD) P51 (STROBE) P52 (B.E.O) Fig Timing Chart for Thermal Head Drive Fig shows the timing chart for thermal head drive. The serial data sent from P45 in synchronization with P46 clock is latched by the LAT signal of P47 and the thermal head is powered on by the STR signal of P51. III - 9

49 3.2.6 Oscillation Circuit ±0V XT MHz 30 XI 31 CPU #1 XOUT Fig Oscillation Circuit Fig shows the oscillation circuit. This circuit contains an oscillator and generates an oscillation at 8.00 MHz (basic clock for the CPU). This clock permits the circuit inside the CPU to operate at 4.00 MHz, the half of this clock frequency Buzzer Circuit CPU #1 P20 40 R10 3.3K BZ1 +5V 125 µs P µs Buzzer-beeping generated Fig Buzzer Circuit and Drive Waveforms Fig shows the buzzer circuit and drive waveforms. This circuit drives a piezoelectric sounder by the oscillation waveforms at 4 KHz. III - 10

50 3.2.8 LED Drive Circuit Fig shows the LED related circuit. Fig shows the timing chart for LED drive. +5V CPU #1 P24 P25 P26 P R R R R LD1 (red) LD2 (green) Fig LED Related Circuit Power O Power OFF Key input During priting P24 3 ms 11 ms P25 P26 P27 Green LED turns on Red LED turns on Fig Timing Chart for LED Drive III - 11

51 V Power Supply Circuit Fig shows the 5V power supply circuit. +5BV is generated by a 3 terminal regulator S-81250PG. Q2 S-81250PG +5V 3 OUT I 2 C2 6.3V 47µ GD 1 C1 10V 2200µ 1 B 2 B P1 (battery terminal) ±0V Fig V Power Supply Circuit III - 12

52 3.3 TROUBLESHOOTIG This section gives the service personnel some of the troubleshooting procedures to be followed if an error or malfunction occurs with the PT-100. 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. However, those samples will help service personnel pinpoint and repair other defective elements if he/she analyzes and examines them well Precautions Be sure to observe the following precautions to prevent the secondary problems from happening during troubleshooting: (1) Get a good idea of what the trouble is. Whenever more than one trouble source is found, plan the most reasonable repairing procedure after reviewing the relationship between them. (2) When supplying power to the PT-100 having problems from either a set of batteries, make sure that its output voltage level is 8 to 10V under no load. (3) When supplying power from a stabilized power unit, use the power unit with approx. 3A capacity and choose the output level of 7 to 9V. When connecting it to the PT-100, be careful with the polarity. (4) When using a circuit tester for testing the conductivity, remove all of the batteries from the PT-100. (5) To repair an error which occurred in the thermal print head and its related sections, disconnect the thermal head cable until repairs are finished After Repairing After repairing the defective section, be sure to check again to see if the repaired section works correctly. Also make a note of the troubleshooting procedure so that it will be handy should problems occur in the future. III - 13

53 3.3.3 Troubleshooting Flows [1] Tape feeding failure The tape will not feed through. C (from CHAPTER II, Subsection 2.3.3, [1].) Output on pin 28 of LSI #1 is normal? LSI #1 is defective. Replace the main PCB. Transistor Q1 turns on and off normally? Q1 is defective. Replace the main PCB. End [2] Printing failure The tape is fed normally but no printing occurs. E (from CHAPTER II, Subsection 2.3.3, [2].) Output on pins 17 through 22 of LSI #1 is normal? LSI #1 is defective. Replace the main PCB. Head connector P3 on the main PCB is normal? P3 is defective. Replace the main PCB. The print head is defective. Replace it. III - 14

54 [3] Powering failure (Red LED is not turn on.) Turning on the O key does not power the machine; red LED does not turn on. F (from CHAPTER II, Subsection 2.3.3, [3].) The +5BV is normal (within +5±0.15V)? Is the +5V line short-circuited to GD? Transistor Q2 is normal? Replace the main PCB. Output on pins 24 and 27 of LSI #1 is normal? The rubber spring of the keyboard is defective. Replace the keyboard. The battery output is 7V or more? Replace the batteries with new ones. The CPU cannot read the signal on pin 76 of LSI #1. Replace the main PCB. III - 15

55 [4] Abnormal LED indication LED light is abnormal. Output signals on pins 33 through 36 of LSI #1 are normal? LSI #1 is defective. Replace the main PCB. LED indication circuit is defective. Replace the main PCB. [5] o key entry possible o key entry is possible. G (from CHAPTER II, Subsection 2.3.3, [4].) Is any key stuck to O? The key pad pattern is defective. Replace the main PCB. The key scanning signal is normal? LSI #1 is defective. Replace the main PCB. Replace the keyboard. III - 16

56 [6] Abnormal buzzer Buzzer-beeping is abnormal. Output on pin 40 of LSI #1 is normal? LSI #1 is defective. Replace the main PCB. Piezoelectric sounder BZ1 is defective. Replace the main PCB. III - 17

57 APPEDIX CIRCUIT DIAGRAM Main (Control) PCB

58 P20 P21 P22 ( U) P2 3 P24 P25 P26 P27 VSS XOUT XI P4 0 ( U) P41 RESET CVSS P62 P30 P 6 1 ( U ) ( U) P3 1 P 6 0 ( U ) ( U) P3 2 P77 ( U) P3 3 P76 ( U) P3 4 P75 ( U) P3 5 P74 ( U) P3 6 P73 P37 P72 P00 P71 P01 P70 P02 P 5 7 ( U ) P03 P 5 6 ( U ) P04 P 5 5 ( U ) P05 P 5 4 ( U ) P06 P 5 3 ( U ) P P52 P51 P50 P47 P46( SCLK1) P 4 5 ( T X D ) P10 P11 P12 P13 P14 P P44 P P43 P P P P P P P P P VCC 7 4 VREF 7 5 AVSS 7 6 P P 6 6 ( U ) 7 8 P 6 5 ( U ) 7 9 P 6 4 ( U ) 8 0 P63 ( U) P ( VCC4 ) ( VCC3 ) ( VCC2 ) R R7 1 M R R R K L D 1 ( R ED) L D 2 ( G R E E ) Q 3 D T C K 1 0 K C K O OF F Q 1 B TH ( VCC1 ) R K BZ1 ( 0. 5 %) R K ( 0. 5 %) R K RA2 ( VCC6 ) ADI ( VCC5 ) 0 V 0 V Z D E 3 4 R F X CODE A Q 1 2 W S SHI F C G T 5 6 H V B J U 7 8 I K M L O 9 0 P _C SPACE,? $ PRI T FEED DEL A E B C F G D H KE BOARD ( USA) RA K X 4 CA SOLDER POI T R K + 5 V 0 V 0 V C Z D E 3 4 R F X A Q 1 2 W S CODE SHI F C G T 5 6 H V B J U 7 8 K M L O 9 0 P? SPACE, DEL : C _ $ PRI T FEED KE BOARD ( CAADA) VBT 0 V VBT VBT Q 2 S P G + 5 V OUT I GD C2 C1 B V 1 0 V 4 7 µ µ + 5 V B- 0 V + 5 V VBT C V 0 V 0 V 0 V VH DATA CL OCK L ATCH/ VDD GDH GDL STROBE/ B. E. O VH 0 V P2 ( MOTOR) ADI AME Main (Control) PCB Circuit Diagram CODE U : I V 2 T R K ) ( R K

59 R May, '95 5V2011BE0 Printed in Japan