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Oki ML420 Series Maintenance Manual

Manual is about: High Performance 10/100 Base-T Ethernet Network Print Server

Summary of ML420 Series

  • Page 1

    Oki data confidential ml420/ml421 maintenance manual 080603f printing solutions.

  • Page 2

    Copyright information copyright © 2007 by oki data. All rights reserved disclaimer every effort has been made to ensure that the information in this document is complete, accurate, and up-to-date. The manufacturer assumes no responsibility for the results of errors beyond its control. The manufactur...

  • Page 3: Preface

    42113901th01 rev.3 3 / oki data confidential preface this maintenance manual describes how to maintain the printer in the field. This manual is for customer engineers. For further information, refer to the users manual for handling or operating the equipment. The relation between the destination poi...

  • Page 4: Contents

    42113901th01 rev.3 4 / oki data confidential contents 1. Configuration ...............................................................................................6 1.1 standard printer configuration ............................................................................................ 6 1....

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    42113901th01 rev.3 5 / oki data confidential 3.3.20 rear tractor assy ................................................................................................. 76 3.3.21 rear pressure assy .............................................................................................. 77 3.3.2...

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    42113901th01 rev.3 6 / oki data confidential 1. Configuration 1.1 standard printer configuration this printer consists of the following assemblies: figure 1-1 configuration upper cover access cover assy platen knob sheet guide assy control board power supply board transformer assy pull-up roller ass...

  • Page 7

    42113901th01 rev.3 7 / oki data confidential 1.2 options (1) cut sheet feeder unit (csf) (narrow and wide versions available) dual-bin csf single-bin csf (2) pull-tractor assy attachment assy attachment assy.

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    42113901th01 rev.3 8 / oki data confidential (3) bottom push tractor unit (4) roll paper stand (narrow only) (5) rs232c serial interface board.

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    42113901th01 rev.3 9 / oki data confidential 2. Theory of operation 2.1 electrical operation the electrical operation of the printer circuit is described in this section. 2.1.1 summary figure 2-1 shows the block diagram of the printer. The control board is made up of the microprocessors, peripheral ...

  • Page 10

    42113901th01 rev.3 10 / oki data confidential figure 2-1 htemp 14.456 mhz 4 powlev htemp headgap sptemp a/d pe-sensor operation panel serial alarm -circuit hd alarm over-v alarm over-v alarm fan alarm power-off transformer rectifier circuit 50 volt 12 volt 5 volt 42v -8v 3.3v 5vs reset circuit i/f-i...

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    42113901th01 rev.3 11 / oki data confidential mpu clock a0~a17 pg-n psen-n d0~d15 cso psen ce oe pg-n psen-n d0~d15 a0~a17 mpu rom (2) program rom this is a 256 × 16 bits (4m bit) eprom or mask romwith the control program for the printer stored. The mpu executes instructions under this program. The ...

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    42113901th01 rev.3 12 / oki data confidential a0~a8 cas-n ras-n ucas-n lcas-n wr-n rd-n wrh-n wrl-n ram mpu p03 cs1 wrl p11 rd oe d0~d15 ras ucas lcas we t1 t2 t3 clockout* a0~a8 ras-n vcas-n lcas-n rd-n d0~d15 (read) wr-n d0~d7 (write) 16-bit bus, word instruction als139 als11 t4 * clockout is prov...

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    42113901th01 rev.3 13 / oki data confidential (4) usb controller the usb controller detects and controls the usb interfacee. The following shows the usb controller access operation. D0~d7 p02 psen mpu usbcs-n rd-n wrl-n a0~a7 usb controller clockout * a0~a7 d0~d7 (write) usbcs-n rd-n wrl-n d0~d7 (re...

  • Page 14

    42113901th01 rev.3 14 / oki data confidential mpu eeprom eedin-p eecs-p eedout-p eeclk-p p24 p27 p25 p26 d1 cs do sk ready bus twp d0 d15 a0 a5 1 1 0 start code operation code address data t cs pre = o pe eecs-p eeclk-p eedin-p eedout-p address start code operation code eedout-p eedin-p eeclk-p eecs...

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    42113901th01 rev.3 15 / oki data confidential mpu a/d bus lsi rd wrl p01 ale ale rd-n wrl-n lsics-n ale-p rdn wrl lsic ras 1 p07 ras 0 ras-n clockout* a0~a19 lsics-n ale d0~d7 (read) rd-n d0~d7 (write) wrl-n address address data data * clockout is provided when the original excitation is selected. (...

  • Page 16

    42113901th01 rev.3 16 / oki data confidential end i/f busy off serial i/f i/f ack send parallel i/f lf motor phase initialization carriage homing ram clear lsi initial setting and i/f busy on external ram check lsi reset rom check internal ram check mpu initial setting mpu reset start 2.1.3 initiali...

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    42113901th01 rev.3 17 / oki data confidential a/d bus mpu lsi nbsy ack nstb rxd-n p16 nrxd receive data cn1 busy ack-n strobe-n receive data 1 to 8 strobe-n busy ack-n rxd-n 2~8µs 500ns max. 2.1.4 interface control (1) parallel interface the parallel data input from the host to the interfaced lsi is...

  • Page 18

    42113901th01 rev.3 18 / oki data confidential (2) universal serial bus (usb) universal serial bus specification revision 1.0 compliance. 1) connector • printer side : “b” receptacle (upstream input to the usb device) • cable side : series “b” plug 2) cable • cable length : approx 1.8m (a cable must ...

  • Page 19

    42113901th01 rev.3 19 / oki data confidential 9) signal level • input / output level parameter input levels : high (driven) high (floating) low output levels : low high (driven) output signal crossover voltage symbol v ih v ihz v il ol oh v crs min. 2.0 2.7 0.0 2.8 1.3 max. 3.6 0.8 0.3 3.6 2.0 units...

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    42113901th01 rev.3 20 / oki data confidential head drive timing chart dt1 dt2 head drive current print data mpu lsi driver head1-n~ head9-n print head a/d bus head1~ head9 control board print data 2.1.5 print control print data is transmitted as parallel data (head1~head9) from lsi to print head. Ls...

  • Page 21

    42113901th01 rev.3 21 / oki data confidential as shown in the drawing left, the stroke length up to the platen is different for each pin. Number of impact pins few many drive time short long print head time pin 3~6 pin 1, 2, 8, 9 pin coil current pin 1,2 3~6 8,9 platen print compensation control the...

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    42113901th01 rev.3 22 / oki data confidential 2.1.6 sp/lf motor control the mpu transmits serially the sp motor data and the lf motor control data too the sp/lf motor driver, according to the commands sent from the mpu. Transmission of sp/lf motor control data mpu φ a/ φ b φ a/ φ b φ b φ a lf a1 a2 ...

  • Page 23

    42113901th01 rev.3 23 / oki data confidential sp truth table hall amp input output spu spv spw u v w h h l open l h h l l l open h h l h l h open l l h open h l l h h h open l l h l h l open spu spv spw (1) space motor control the sp motor driver (mhm2025) drives the three-phase brushless motor base...

  • Page 24

    42113901th01 rev.3 24 / oki data confidential 1/720" 1/120" spu spv spw phase-a phase-b 1/144" ipt 10 cpi ipt 12 cpi ipt 15 cpi ipt 17 cpi ipt 20 cpi 1/180" 1/206" 1/240" (2) encoder disk in the operation of the spacing motor, the phase-a and phase-b signals are generated when the encoder disk inter...

  • Page 25

    42113901th01 rev.3 25 / oki data confidential lsi operation panel control ic optxd opclk opclr-n oprxd 48 47 45 optd opck npa2 oprd command and data latch led driver switch controller +5v 46 2.1.7 operation panel the clock synchronization opclk of lsi is used to input the switch data and output the ...

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    42113901th01 rev.3 26 / oki data confidential optxd opclk oprxd opclr-n 1 2 3 2 3 1 6 7 5 or 8 bit0 bit7 command (first) command (second) command response (first) command response (second) note bit0 bit7 reset within ic power on write instruction for ic reset ic write for led data, etc. Read instruc...

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    42113901th01 rev.3 27 / oki data confidential 50v r542 r541 powlev voltage, 50v pass number print speed 38v or more 1 pass 100% 25v to 37v 1 pass 100~30% 25v or less 1 pass 30% 2.1.8 alarm circuit (1) ac fuse open alarm (a) head drive time alarm circuit this circuit monitors the drive time using the...

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    42113901th01 rev.3 28 / oki data confidential stop mode up mode down temp 125 ° c 118 ° c 116 ° c (4) overheat alarm (a) head overheat alarm the voltage of the output htemp signal of the thermistors, one of which is contained in the print head and the other in the sp/lf driver, is monitored by the a...

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    42113901th01 rev.3 29 / oki data confidential stop temp 105 ° c 95 ° c (b) sp motor overheat alarm the voltage of the output sptemp signal of the thermistors, one of which is contained in the sp motor, is monitored by the a/d port of the mpu to control the voltage. Mode and print control • when the ...

  • Page 30

    42113901th01 rev.3 30 / oki data confidential sw ac fuse noise filter circuit trans- former power supply board control board rectifier converter rectifier regulation circuit +50v +12v +5v +5v -8v converter +3.3v +50v converter +42v the uses of output voltages and signals are described below. Voltage...

  • Page 31

    42113901th01 rev.3 31 / oki data confidential 2.2 mechanical operation 2.2.1 printhead mechanism and operation (see figure 2-2.) the printhead is a spring charged 9-pin driving head using a permanent magnet. It is attached to the carriage, which moves in parallel with the platen. Electrically, this ...

  • Page 32

    42113901th01 rev.3 32 / oki data confidential (2) operation of printhead (see figure 2-3.) (a) when the printhead is idle, the armature is attracted by a permanent magnet and the spring fixing the armature is compressed. The print wires fixed to each armature are thus concealed under the wire guide....

  • Page 33

    42113901th01 rev.3 33 / oki data confidential (2) when not printing (1) when printing figure 2-3 paper print wire printhead platen wire guide paper print wire thermistor magnet assembly spacer armature assembly yoke paper.

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    42113901th01 rev.3 34 / oki data confidential 2.2.2 spacing operation (see figure 2-4.) the spacing mechanism consists of a carriage shaft mounted in parallel with the platen, and a carriage frame that moves along the shaft. It is driven by a dc motor mounted on the bottom of the carriage frame. Ite...

  • Page 35

    42113901th01 rev.3 35 / oki data confidential 2.2.3 head gap adjusting (see figure 2-5.) the head gap adjusting lever moves back and forth to tilt the carriage frame, altering the gap between the printhead and the platen. The adjusting screw, which is connected to the adjusting gear rotates when the...

  • Page 36

    42113901th01 rev.3 36 / oki data confidential figure 2-5 range from 5 to 1 range from 1 to 5 platen range platen narrows c.C.W. C.W. Carriage shaft printhead printhead guide rail adjusting screw adjusting screw adjusting gear idler gear adjusting lever 1 2 3 4 5 adjusting cam widens.

  • Page 37

    42113901th01 rev.3 37 / oki data confidential 2.2.4 ribbon drive (see figure 2-6.) the ribbon driver mechanism moves the ribbon in synchronization with the space motor operation. The ribbon drive mechanism consist of the following items: (a) ribbon drive gear assembly (b) ribbon gear (space motor) (...

  • Page 38

    42113901th01 rev.3 38 / oki data confidential 2.2.5 paper feed operation feeding of the paper is performed by turning the platen and the pin tractor, which is driven by the lf pulse motor. Item of the paper feed mechanism are as follows: (a) pulse motor with gears (b) decelerating gear (c) platen (d...

  • Page 39

    42113901th01 rev.3 39 / oki data confidential (1) cut sheet and continuous sheet switching mechanism (see figure 2-7.) three different paper paths can be selected and set by the change lever. (a) top (for cut sheet) when the cut sheet is used in the manual mode or fed by the csf (option), set the ch...

  • Page 40

    42113901th01 rev.3 40 / oki data confidential change arm change lever change gear shaft rear switch bottom switch switch lever control power supply assy release shaft figure 2-7 top bottom change lever tractor gear change gear rear reset spring platen gear (r) platen idle gear (bottom tractor unit).

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    42113901th01 rev.3 41 / oki data confidential (2) cut-sheet feeder operation (see figure 2-8.) the pulse motor used for the paper feed mechanism is mounted on the left of the frame, and the rotation of the motor is transmitted through decelerating gears (lf idle gear, platen gear) to the platen. Whe...

  • Page 42

    42113901th01 rev.3 42 / oki data confidential figure 2-9 (3) continuous paper feed operation (rear) (see figure 2-9.) the force transmitted to the platen, rotates the tractor gear through platen gear, the idler gear and the change gear. The rotation of the tractor gear makes the pin tractor belt rot...

  • Page 43

    42113901th01 rev.3 43 / oki data confidential (4) push and pull tractor mechanism (option) (see figure 2-10). This mechanism consist of an optional pull tractor and a standard push tractor mechanism. This mechanism can perform forward and reverse feed by setting continuous sheets to the push tractor...

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    42113901th01 rev.3 44 / oki data confidential figure 2-11 continuous sheet form pull tractor assembly sheet feeder shaft drive gear lf motor idle gear lf idle gear platen gear platen (5) pull tractor mechanism (option) (see figure 2-11.) bottom feed of continuous sheets is possible only when an opti...

  • Page 45

    42113901th01 rev.3 45 / oki data confidential figure 2-12 idle gear tractor change gear tractor idle gear tractor drive gear platen gear change gear platen (6) bottom push feed operation (option) (see figure 2-12.) the bottom push feed of the continuous sheet is possible only when the bottom tractor...

  • Page 46

    42113901th01 rev.3 46 / oki data confidential (7) paper clamp mechanism (see figure 2-13.) when setting the change lever to the bottom , top or rear position, the operation of the front release gear arm changes according to the position of the release cam. And at the same time, the position of the c...

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    42113901th01 rev.3 47 / oki data confidential figure 2-13 top bottom rear change lever front release gear arm platen release cam.

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    42113901th01 rev.3 48 / oki data confidential figure 2-14 bottom paper end lever paper end sensor paper end lever sensor lever shaded portion b a 2.2.6 paper detection mechanism (see figure 2-14.) (1) cut sheet detection when the cut sheet is inserted, the point a is pushed backward and the paper ne...

  • Page 49

    42113901th01 rev.3 49 / oki data confidential figure 2-15 printhead carriage frame assembly platen ribbon protector (4) top line print mechanism (see figure 2-15.) the front edge of the sheet is protected by the ribbon protector so that it can stop at a position just near to the print head (0 tear o...

  • Page 50

    42113901th01 rev.3 50 / oki data confidential 2.2.7 automatic sheet feed this function is used to feed in the sheet automatically up to the print start position when the cut sheet or the continuous sheet is used. [operational procedure] (1) when using the cut sheet 1) set the change lever to the top...

  • Page 51

    42113901th01 rev.3 51 / oki data confidential detection of the sheet supplied pe lf action line feed (about 3 inches) until the detection of the sheet supplied (2) when using the continouos paper 1) set the change lever either to the rear side or the bottom side position. (see figure 2-16.) 2) set a...

  • Page 52

    42113901th01 rev.3 52 / oki data confidential paper end detection pe reverse lf until paper end or 19 inches max. Lf action park reverse lf from p.E. Sensor to tractor feed assy. 2.2.8 paper park function (continuous paper) continuous sheets which have been inserted can be reversed automatically by ...

  • Page 53

    42113901th01 rev.3 53 / oki data confidential 3. Assembly/disassembly this section explains the procedures for removing and installing various assemblies and units in the field. Description is mainly limited to the removal procedure; installation should basically be performed in the reverse sequence...

  • Page 54

    42113901th01 rev.3 54 / oki data confidential 3.2 service tools table 3.1 lists the tools necessary for replacing printed circuit boards and parts of units in the field. Table 3.1 service tools 1 no. 1-100 phillips 1 screws screwdriver 2.6 mm 2 no. 2-200 phillips 1 screws screwdriver 3-5 mm 3 no. 3-...

  • Page 55

    42113901th01 rev.3 55 / oki data confidential figure 3-1 printer unit 3.3 disassembly/reassembly procedure this section explains the assembly replacement procedures according to the following disas- sembly system. [parts layout] operation panel board control board power supply board transformer assy...

  • Page 56

    42113901th01 rev.3 56 / oki data confidential [how to change parts] this section explains how to change parts and assemblies appearing in the disassembly diagram below. Printer unit 3.3.1 printhead 3.3.2 ribbon protector 3.3.3 pull-up roller assy 3.3.4 upper cover, access cover and sheet guide 3.3.5...

  • Page 57

    42113901th01 rev.3 57 / oki data confidential figure 3.3.1 figure 3.3.2 3.3.1 printhead (1) open the access over. (2) pull up and rotate the head clamp 1 to unclamp the printhead 2 as shown fig. 3.3.1. (3) disconnect the printhead 2 from pc connector 3. (4) to install, follow the removal steps in th...

  • Page 58

    42113901th01 rev.3 58 / oki data confidential 3.3.2 ribbon protector (1) remove the printhead (see 3.3.1). (2) open the pull-up roller cover 1. (3) raise and remove the ribbon protector 2. (4) to install, follow the removal steps in the reverse order. 2 1.

  • Page 59

    42113901th01 rev.3 59 / oki data confidential 3.3.3 pull-up roller assy (1) open the access cover 1. (2) lift up the sheet guide assy 4 to remove. (3) tilting the pull-up roller assy 2 toward the front, remove from the shaft of platen assy 3 . (4) to install, follow the removal steps in the reverse ...

  • Page 60

    42113901th01 rev.3 60 / oki data confidential 3.3.4 upper cover assy, access cover assy and sheet guide assy (1) pull off the platen knob 1. (2) turn the change lever 2 toward the bottom position. (3) insert a flat-blade screwdriver into grooves (5 places) (4 places for narrow type) of frame and twi...

  • Page 61

    42113901th01 rev.3 61 / oki data confidential 3.3.5 gear case assy (1) remove the printhead (see 3.31). (2) remove the upper cover (see 3.3.4 (1) – (5)). (3) move the carriage assy to right hand side, remove two screws 1, then the space motor 2. (4) disconnect a carriage cable. (5) disengage claws (...

  • Page 62

    42113901th01 rev.3 62 / oki data confidential 3.3.6 pc connector (1) remove the printhead (see 3.3.1). (2) remove the upper cover (see 3.3.4 (1) – (5)). (3) remove the gear case assy (see 3.3.5). (4) remove the pc connector 1 from the space motor assy 2. (5) to install, follow the removal steps in t...

  • Page 63

    42113901th01 rev.3 63 / oki data confidential 3.3.7 space motor, guide roller assy (1) remove the printhead (see 3.3.1). (2) remove the upper cover (see 3.3.4 (1) – (5)). (3) remove the gear case assy (see 3.3.5). (4) remove the pc connector (see 3.3.6). (5) remove screw 2, then the guide roller ass...

  • Page 64

    42113901th01 rev.3 64 / oki data confidential 3.3.8 space rack (1) remove the printhead (see 3.3.1). (2) remove the upper cover (see 3.3.4 (1) – (5)). (3) remove the gear case assy (see 3.3.5). (4) remove the space motor (see 3.3.7). (5) remove the spring 1. (6) disengage the claw on left side of sp...

  • Page 65

    42113901th01 rev.3 65 / oki data confidential 3.3.9 carriage cable (1) remove the printhead (see 3.3.1). (2) remove the upper cover (see 3.3.4 (1) – (5)). (3) remove the gear case assy (see 3.3.5). (4) remove the space motor (see 3.3.7). (5) remove the space rack (3.3.8). (6) remove two screws 1, re...

  • Page 66

    42113901th01 rev.3 66 / oki data confidential 3.3.10 backup roller holder assy (1) remove the printhead (see 3.3.1), (2) remove the upper cover (see 3.3.4 (1) – (5)). (3) remove the gear case assy (see 3.3.5). (4) remove the space motor (see 3.3.7). (5) remove the backup roller spring 2. Disengage c...

  • Page 67

    42113901th01 rev.3 67 / oki data confidential 3.3.11 platen assy (1) remove the printhead (see 3.3.1). (2) remove the ribbon protector (see 3.3.2). (3) remove the pull-up roller assy (see 3.3.3). (4) remove the upper cover (see 3.3.1 (1) – (5)). (5) turn the change lever 1 to the bottom position. (6...

  • Page 68

    42113901th01 rev.3 68 / oki data confidential 3.3.12 control board (nns) (1) remove the upper cover (see 3.3.4 (1) – (5)). (2) remove two screws 1, and release the control board 2 and pcb sheet 5 by lifting clamp 4. (3) disconnect all cables from control board 2. (4) to install, follow the removal s...

  • Page 69

    42113901th01 rev.3 69 / oki data confidential 3.3.13 lf motor (1) remove the printhead (see 3.3.1). (2) remove the ribbon protector (see 3.3.2). (3) remove the pull-up roller assy (see 3.3.3). (4) remove the upper cover (see 3.3.4 (1) – (5)). (5) remove the platen assy (see 3.3.11). (6) remove the d...

  • Page 70

    42113901th01 rev.3 70 / oki data confidential 3.3.14 operation panel board (leop) (1) remove the upper cover (see 3.3.4 (1) – (5)). (2) disconnect the cable 1 from connector 3 of control board 2. (3) disengage claws on both sides from the frame, and remove the operation panel 4. (4) open claws (4 pl...

  • Page 71

    42113901th01 rev.3 71 / oki data confidential 3.3.15 power supply board (tpw) (1) remove the upper cover (see 3.3.4 (1) – (5)). (2) disconnect two flexible cable 3 from the connector 2 the power supply board 1. (3) remove the cable 5 from the connector 4 on the power supply board 1. (4) remove two s...

  • Page 72

    42113901th01 rev.3 72 / oki data confidential 3.3.16 transformer assy (1) remove the upper cover (see 3.3.4 (1) – (5)). (2) remove ac inlet 1 and ac switch 2 from the frame guide. (3) disconnect the cable 3 from the connector 4 on the power supply board 5. (4) remove a screw 6 and disconnect ground ...

  • Page 73

    42113901th01 rev.3 73 / oki data confidential 3.3.17 change lever and gears (1) remove the upper cover (see 3.3.4 (1) – (5)). (2) remove the reset spring 1, then remove the idle gear 2, the tractor gear 4 and the change gear 5. (3) push back the protrusion of the change gear shaft 6 with a flatblade...

  • Page 74

    42113901th01 rev.3 74 / oki data confidential 3.3.18 carriage shaft (1) remove the printhead (see 3.3.1). (2) remove the upper cover (see 3.3.4 (1) – (5)). (3) remove the driver board (see 3.3.12). Remove the fg plate (l) 2. (4) slide the carriage shaft 1 to the left side (in the direction of the ar...

  • Page 75

    42113901th01 rev.3 75 / oki data confidential 3.3.19 paper pan (1) remove the printhead (see 3.3.1). (2) remove the ribbon protector (see 3.3.2). (3) remove the pull-up roller assy (see 3.3.2). (4) remove the upper cover assy (see 3.3.4 (1) – (5)). (5) remove the platen assy (see 3.3.11). (6) releas...

  • Page 76

    42113901th01 rev.3 76 / oki data confidential 3.3.20 rear tractor assy (1) remove the printhead (see 3.3.1). (2) remove the ribbon protector (see 3.3.2). (3) remove the pull-up roller assy (see 3.3.3) (4) remove the upper cover (see 3.3.4 (1) – (5)). (5) remove the reset spring (see 3.3.17 (3)) (6) ...

  • Page 77

    42113901th01 rev.3 77 / oki data confidential 3.3.21 rear pressure assy (1) remove the upper cover (see 3.3.4 (1) – (5)). (2) remove the change lever and gears (see 3.3.17). (3) remove the paper pan (see 3.3.19). (4) remove the rear pressure roller 1. (5) rotate the release shaft 2 and move it to th...

  • Page 78

    42113901th01 rev.3 78 / oki data confidential micro switch switch lever switch lever 3.3.22 switch lever (1) remove the upper cover (see 3.3.4 (1) – (5)). (2) remove the change lever and gears (see 3.3.17). (3) remove the paper pan (see 3.3.19). (4) remove the rear pressure assy (see 3.3.21). (5) pu...

  • Page 79

    42113901th01 rev.3 79 / oki data confidential 4. Adjustment (1) be sure to carry out this adjustment with the printer mechanism mounted on the lower cover. (2) be sure to carry out this adjustment operation on a level and highly rigid work table (flatness: less than 0.039 inch or 1 mm) so as to mini...

  • Page 80

    42113901th01 rev.3 80 / oki data confidential item no. Specification drawing adjustment method gap between the plat- en and the print head 1) parallelism ad- justment 4–1–1 variation of value at the left, the center and the right shall be less than 0.02 mm it shall be measured at 3 points: the left ...

  • Page 81

    42113901th01 rev.3 81 / oki data confidential item no. Specification drawing adjustment method note 1) the head gap shall be measured with the change lever set to rear position. Note 2) the head gap shall be measured positioning the platen gear (r) craw on the top. Note 3) move the adjust screw in c...

  • Page 82

    42113901th01 rev.3 82 / oki data confidential item no. Specification drawing adjustment method gap between the con- tact and the monitor 0.3mm or more confirm followings. Make sure that the gap between the con- tact and the motor pcb is 0.3 mm or more. At the time of printing test, make sure that th...

  • Page 83

    42113901th01 rev.3 83 / oki data confidential item no. Specification drawing adjustment method 4–2 1 ± 0.5 confirm followings. (1) when the change lever is set at friction position, the gap between the platen and the paper pan at the rear side shall be 1 ± 0.5mm. (2) when the change lever is set at ...

  • Page 84

    42113901th01 rev.3 84 / oki data confidential item no. Specification drawing adjustment method rotation of the push tractor 4–4–1 to confirm: the tractor gear shall rotate smoothly when the change lever is set at friction posi- tion. Backlash between gears 4–4–2 approx. 0.05 to 0.11 mm to confirm: t...

  • Page 85

    42113901th01 rev.3 85 / oki data confidential item no. Specification drawing adjustment method ribbon feed 4–5–1 to confirm: ribbon shall be fed smoothly when the carriage is moved from side to side. Running load to spac- ing mechanism 4–5–2 to confirm: make sure that the power is turned off at the ...

  • Page 86

    42113901th01 rev.3 86 / oki data confidential item no. Specification drawing adjustment method 4–6 to confirm: the idle gear of the lf motor and the platen gear (l) and the bias gear of the platen shall be in mesh in such way that the platen gear (l) and the bias gear rotate against each other to pi...

  • Page 87: Cleaning And Lubrication

    42113901th01 rev.3 87 / oki data confidential 5. Cleaning and lubrication 5.1 cleaning [cautions] 1. Be sure to turn off the ac power switch before cleaning. Remove the ac power cord from the printer. 2. Avoid dust inside the printer mechanism when cleaning. 3. If a lubricated part has been cleaned,...

  • Page 88

    42113901th01 rev.3 88 / oki data confidential 5.2 lubrication this printer is designed to be maintenance free and requires no lubrication during normal operation. However it is necessary to apply lubricant in case the printer is disassembled, reassembled, cleaned or parts have been changed. (1) clea...

  • Page 89

    42113901th01 rev.3 89 / oki data confidential (5) lubrication point 1. Ribbon feed gear assy. 2. Space rack drive gear shaft (upper and lower) pm-b (0.006–0.002g) idle gear shaft (upper and lower) pm-b (0.006±0.002g) planetary gear shaft (upper and lower) em-30l-a space rack rack upper side approx. ...

  • Page 90

    42113901th01 rev.3 90 / oki data confidential 3. Platen assy. Bias gear platen gear (l) grease the contact face of platen gear (l) and bias gear pm-b.

  • Page 91

    42113901th01 rev.3 91 / oki data confidential 4. Tractor driving mechanism 5. Tractor drive shaft 12345 12345 12345 12345 a-a arrow view sliding surface of fg spring and drive shaft end em-30l-a drive shaft bearing portion em-30l-a drive shaft bearing portion em-30l-a change lever tractor gear beari...

  • Page 92

    42113901th01 rev.3 92 / oki data confidential 6. Pressure roller release shaft protruding portion - 2 portions em-30l-a rear roller holder shaft contact portion of rear holder and shaft em-30l-a contact portion of support spring and shaft em-30l-a sliding portion of release shaft and rear roller hol...

  • Page 93

    42113901th01 rev.3 93 / oki data confidential 7. Pull up roller assy. Pull-up roller frame pull-up roller shaft all bearing portions of pull-up roller shaft and pull-up roller frame em-30l-b gear and post em-30l-a.

  • Page 94

    42113901th01 rev.3 94 / oki data confidential 8. Main chassis assy. Grease portion grease portion at rib (n: 9 portions) em-30l-a grease portion (n: 3 portions) rear side em-30l-a 9. Carriage assy. Nk2-10-sus bearing portion of guide roller em-30l-b.

  • Page 95

    42113901th01 rev.3 95 / oki data confidential 6. Troubleshooting and repair 6.1 items to check before repair (1) check the inspection items specified in the instruction manual. (2) find out as many details of the trouble as possible from the customer. (3) inspect in the conditions as close as possib...

  • Page 96

    42113901th01 rev.3 96 / oki data confidential alarm category alarm led condition contents trouble shooting alarm sel menu 10cpi 15cpi operator alarm paper end alarm on off — — — from, cut sheet or bottom paper end set new paper. Paper change lever alarm on off — blink 1 off change lever is set to to...

  • Page 97

    42113901th01 rev.3 97 / oki data confidential alarm category alarm led display alarm 10 12 15 17 20 prop hsd utl nlq remarks troubleshooting main control alarm firmware detection alarm serial interface alarm mpu internal ram alarm program rom alarm ram on control board alarm eeprom alarm wdt (watch ...

  • Page 98

    42113901th01 rev.3 98 / oki data confidential alarm category alarm led display alarm 10 12 15 17 20 prop hsd utl nlq remarks troubleshooting spacing alarm spacing alarm print head homing alarm print head a/d alarm space ipt is not occurred within in specified timing. : led blink (200ms on, 200ms off...

  • Page 99

    42113901th01 rev.3 99 / oki data confidential switch ac connector power supply board transformer centro-connector space motor lf motor fan motor print head control board operation panel board.

  • Page 100

    42113901th01 rev.3 100 / oki data confidential 6.4 connection circuit check for printhead and sp/lf motor (1) printhead signal connector pin number cn1 1 #1 2 #2 3 #4 4 #6 5 #8 6 7 8 9 10 11 #9 12 #7 13 #5 14 #3 15 thermistor (5k Ω at 25 ° c) head1 head2 head4 head6 head8 0v htemp +50v +50v +50v hea...

  • Page 101

    42113901th01 rev.3 101 / oki data confidential (2) line feed motor resistance of each coil should be about 10.4 Ω . Signal connector pin number lf1 lf2 lf3 lf4 cn4 lf motor 1 2 3 4 (3) space motor resistance of each coil should be about 22.4 Ω . Signal connector pin number sp-u sp-v sp-w spa spb spt...

  • Page 102

    42113901th01 rev.3 102 / oki data confidential 6.5 troubleshooting flow chart 1 power is not supplied. Is the ac cable connected correctly? Yes no connect the ac cable correctly. Is fuse f1 on the transformer assy/or f1 on the power supply board blown? No yes replace fuse (with same type and rating)...

  • Page 103

    42113901th01 rev.3 103 / oki data confidential pin no. 20 19 18 17 16 15 14 13 12 11 10 9 8 7 4 3 1 signal 50v 0v +5v 0v +12v -8v no yes replace control board. Replace transformer assy. Remedied? No yes end replace power supply board. Control board cn2 20 1.

  • Page 104

    42113901th01 rev.3 104 / oki data confidential 2 no spacing operation (the alarm led blinks) is carriage assembly binding or jammed? No yes check around space motor to repair the mechanism of space rack, back up roller, ribbon feed mechanism, and carriage frame etc. Replace space motor assy. Remedie...

  • Page 105

    42113901th01 rev.3 105 / oki data confidential 3 homing does not end normally yes no check around space motor to repair the mechanism. (space rack, ribbon feed assembly back up roller, carriage frame, support protector and ribbon protector.) remedied? No yes end replace space motor assy. Replace spa...

  • Page 106

    42113901th01 rev.3 106 / oki data confidential 4 paper jam while paper insertion jam 1 check around pressure roller mechanism. • front pressure springs are narrow: 3 pcs; wide: 5 pcs) mounted properly or not. • tension of all of front pressure rollers is properly. • make sure of the fitting position...

  • Page 107

    42113901th01 rev.3 107 / oki data confidential 5 smearing/missing dots does alarm led blink and display alarm? No yes see tables 6.2 and 6.3 for troubleshooting information. Replace printhead. Remedied? No yes end replace control board. Remedied? No yes end replace carriage cable or space motor assy...

  • Page 108

    42113901th01 rev.3 108 / oki data confidential 6 faint or dark print is the print head gap set properly? Yes no adjust the printhead gap (see section 5). Remedied? No yes end replace printhead. Remedied? No yes end replace control board. Remedied? No yes end replace ribbon feed mechanism..

  • Page 109

    42113901th01 rev.3 109 / oki data confidential 7 ribbon feed trouble remove the ribbon cartridge. Move carriage to left and right. Does the ribbon drive shaft rotate? No yes change ribbon cartridge. Remove ribbon feed mechanism. Move carriage to left and right. Does the ribbon drive shaft rotate? No...

  • Page 110

    42113901th01 rev.3 110 / oki data confidential 8 line feed trouble turn the power off, and rotate the platen manually. Does the platen rotate smoothly? Yes no is the platen gear (l) broken? No yes replace platen assembly. Is the lf motor idle gear broken? No yes replace the lf motor assembly or lf i...

  • Page 111

    42113901th01 rev.3 111 / oki data confidential 9 malfunction of switch on operation panel is the cn1 of operation panel connected to the cn3 on the control board? Yes no connect the cable properly. Replace operation panel board. Remedied? No yes end replace control board..

  • Page 112

    42113901th01 rev.3 112 / oki data confidential 0 data receiving failure is the sel led blinking? No yes printer went into the print suppress mode. Wait until printer to receives dc1 code, or change the menu item “print sup- press-ineffective” when the function is not required. Is the i/f rs232c? No ...

  • Page 113

    42113901th01 rev.3 113 / oki data confidential 10-2 (rs232c i/f) printer i/f pin assignment. Is the correct cable used? Txd 2 pin, rxd 3 pin, yes no ssd 11 pin, dtr 20 pin, change i/f cable. Dsr 6 pin. Is alarm led blinking? No yes see tables 6.2 and 6.3 for the troubleshooting. Make sure of the par...

  • Page 114

    42113901th01 rev.3 114 / oki data confidential appendix a pcb layout pcb list (1) circuit board tpw (power supply board) (2) circuit board nns (control board) (3) circuit board leop (operation panel board) (1) (2) (3) cn3 cn1 cn2 cn4 cn1 cn3 cn7 cn8 cn6 cn10 cn5.

  • Page 115

    42113901th01 rev.3 115 / oki data confidential appendix b spare parts list quantity per year: indicates the recommended number of each part that should be ordered for routine maintenance for one year for 500 units of printers and assuming that the printers are operated for 2 hours/day of 600 hours/y...

  • Page 116

    Table b-1 upper cover assy no. Part no. Description qty qty required remarks 1 42040801 upper cover (n) 1 2 ml420 (beige) 42040802 upper cover (n) 1 2 ml420 (black) 42040901 upper cover (w) 1 2 ml421 (beige) 42040902 upper cover (w) 1 2 ml421 (black) 2 51009409 sheet gude assy (n) 1 2 ml420 (beige) ...

  • Page 117

    42113901th01 rev.3 117 / oki data confidential figure b-2 printer general assy 6 9 7 1 2 3 11 10 4 5 8.

  • Page 118

    Table b-2 printer general assy no. Part no. Description qty qty required remarks 1 51902220 platen knob 1 1 beige 40211004 platen knob 1 1 black 2 42024002 power supply board (tpw) 1 9 3 42021802 control board (nns) 1 9 4 55081107 op panel board (leop) 1 3 5 42116101 operation panel 1 2 beige 421164...

  • Page 119

    42113901th01 rev.3 119 / oki data confidential figure b-3 printer unit a a b b 29 30 23 7 6 15 20 11 19 12 27 25 26 24 28 1 31 21 10 9 2 17 14 33 34 35 32 8 37 18 42 22 13 5 4 3 16 14 41 40 36 38 39.

  • Page 120

    Table b-3 printer unit (1/2) no. Part no. Description qty qty required remarks 1 42114901 main chassis assy (n) 1 2 ml420 (beige) 42114902 main chassis assy (n) 1 2 ml420 (black) 42115001 main chassis assy (w) 1 2 ml421 (beige) 42115003 main chassis assy (w) 1 2 ml421 (black) 2 50809201 bottom paper...

  • Page 121

    Table b-3 printer unit (2/2) no. Part no. Description qty qty required remarks 23 50114801 platen assy (n) 1 3 50114901 platen assy (w) 1 3 24 53349601 space rack gear (n) 1 3 53349701 space rack gear (w) 1 3 25 50923502 tension spring (space rack) 1 1 26 51022201 guide rail plate (n) 1 1 51022301 g...

  • Page 122

    42113901th01 rev.3 122 / oki data confidential figure b-4 carriage assy 12 9 8 6 14 4 10 7 11 13 3 1.

  • Page 123

    Table b-4 carriage option assy no. Part no. Description qty qty required remarks 1 53349801 carriage frame set 1 2 2 3 53343201 back up roller holder assy 1 2 4 40493301 guide roller assy 1 2 5 6 42103601 space motor assy 1 4 7 42252703 head cable (23) 1 5 ml420 42252701 head cable (23) 1 5 ml421 8 ...

  • Page 124

    42113901th01 rev.3 124 / oki data confidential figure b-5 option spare parts [pull-tractor] [bottom-tractor] [i/f board] 3 2 1 4 5 6 7.

  • Page 125

    Table b-5 option spare parts no. Part no. Description qty qty required remarks 1 50098001 pull & bottom tractor l 1 2 2 50097901 pull & bottom tractor r 1 2 3 53077201 tractor cover assy (n) 1 3 ml420 53077301 tractor cover assy (w) 1 3 ml421 4 51902301 bottom push stand l 1 2 beige 42451601 bottom ...

  • Page 126

    42113901th01 rev.3 126 / oki data confidential appendix c rs-232c serial interface board (option) 1. General this section describes the operation of the rs-232c serial interface board installed in the printer as an option using a start-stop synchronization and serial communications circuit. This ser...

  • Page 127

    42113901th01 rev.3 127 / oki data confidential ocs p1 p2 p0 p3 td rd if wr ls245 rom 64kbit rd td ram 64kbit driver +5 vd +12vdc -8vdc +5 v +9 v – 9 v +5v 0v ± 9 v power supply circuit serial data control line bus line control line adr latch receiver db0 to db9 adr/data bus adr bus 80c51 rst cn1 751...

  • Page 128

    42113901th01 rev.3 128 / oki data confidential 2.3 communication procedure flowchart 2.3.1 mode a ready/busy received one character? Yes is dsr valid? No buffer overflow? Error? Parity error no error store the received character in buffer. Is the printer in deselect state or is the paper low? No no ...

  • Page 129

    42113901th01 rev.3 129 / oki data confidential 2.3.2 mode b figure c-3 x-on, x-off received one character? Yes is dsr valid? No buffer overflow? Error? Parity error no error store the received character in buffer. Is the printer in deselect state or is the paper low? No no yes yes no dsr high? Yes s...

  • Page 130

    42113901th01 rev.3 130 / oki data confidential no check the rst circuit on the control board. A 3. Troubleshooting flowchart 3.1 before repairing a fault before servicing the printer, ask the customer in what situation the trouble occurred and record the response. Before starting troubleshooting, op...

  • Page 131

    42113901th01 rev.3 131 / oki data confidential no replace the q2. Yes replace the q3. A yes are ale, psen, rd, wr, signals as specified in figure c-6? Figure c-7 542ns 180ns 271ns 542ns 5v 0v 5v 0v 5v 0v ale psen rd/wr figure c-6 st bit sp bit 5v 0v 5v 0v rxd ssd no replace the q3. Yes are (t1) sele...

  • Page 132

    42113901th01 rev.3 132 / oki data confidential 2 in receiving by serial interface, printing data is omitted or printing operation is not performed. Are rxd and ssd of q3 as specified in figure c-7? No replace the q2. Yes are, wr, and bus signals of q3 pin 3 as specified in figure c-8? No replace the...

  • Page 133

    42113901th01 rev.3 133 / 133 oki data confidential equivalent to cannon db-25p td rd rts cts cd ssd dtr dsr 2 3 4 5 8 11 20 6 3.3 local test 3.3.1 circuit test mode 3.3.1.1 setting (1) diagnostic test (set by menu) (2) test connector connect the test connector shown in figure c-9 to the interface co...