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Oki ML490 Series Maintenance Manual

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

Summary of ML490 Series

  • Page 1

    42114101 rev.1 1 / 135 ml490/491 printer maintenance manual oda.

  • Page 2

    42114101 rev.1 2 /.

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    42114101 rev.1 3 / preface this maintenance manual describes how to maintain the ml490/491 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 point and the model...

  • Page 4: Contents

    42114101 rev.1 4 / contents 1. Configuration ...............................................................................................6 1.1 standard printer configuration ............................................................................................ 6 1.2 options ...................

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    42114101 rev.1 5 / 3.3.20 rear tractor assy ................................................................................................. 77 3.3.21 rear pressure assy .............................................................................................. 78 3.3.22 switch lever ..............

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    42114101 rev.1 6 / 1. Configuration 1.1 standard printer configuration this printer consists of the following assemblies: figure 1-1 configuration transformer assy pull-up roller assy control board power supply board upper cover access cover assy platen knob sheet guide assy main chassis assy operat...

  • Page 7

    42114101 rev.1 7 / 1.2 options (1) cut sheet feeder unit (csf) (narrow and wide versions available) dual-bin csf single-bin csf attachment assy attachment assy (2) pull-tractor assy.

  • Page 8

    42114101 rev.1 8 / (3) bottom push tractor unit (4) roll paper stand (narrow only) (5) rs232c serial interface board.

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    42114101 rev.1 9 / 2. Theory of operation 2.1 electrical operation the electrical operation of the printer circuit is described in this section. 2.1.1 summary fig. 2-1 shows the block diagram of the printer. The control board is made up of the microprocessors, peripheral circuits, drive circuits, se...

  • Page 10

    42114101 rev.1 10 / figure 2-1 ac-input sw ac fuse 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-ipt pri...

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    42114101 rev.1 11 / mpu clock a0~a18 pg-n psen-n d0~d15 cso psen ce oe pg-n psen-n d0~d15 a0~a18 mpu program rom (2) program rom this is a 512k × 16 bits (8m bit) [max 16m bit] otprom or mask rom with the control program for the printer stored. The mpu executes instructions under this program. The p...

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    42114101 rev.1 12 / (3) ram the ram is cmos dynamic ram with 256k × 16-bit (4m bit), and used as buffers (such as receiving buffer, printing buffer, dll buffer and working buffer). The following shows the examples of the memory access operation. * clockout is provided when the original excitation is...

  • Page 13

    42114101 rev.1 13 / 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 (read) ce wr po2 wrl rd rd (4) usb controller the usb controller detects and controls the usb interfacee. The following shows the usb controller access operation. * ...

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    42114101 rev.1 14 / (5) eeprom the eeprom is a cmos serial i/o type memory which is capable of electrically erasing and writing 1,024 bits. The eeprom contains menu data. The following shows the memory access operation. ; ; ; ;; ;; ; ; ; mpu eeprom eedin-p eecs-p eedout-p eeclk-p p24 p27 p25 p26 d1 ...

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    42114101 rev.1 15 / (6) lsi this lsi detects and controls the sp motor speeds by monitoring the two phase sensor signals obtained from the dc motors and modifying the excitation phases as appropriate. This lsi is connected in multiplex to the mpu. Mpu a/d bus lsi rd wrl p01 ale ale rd-n wrl-n lsics-...

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    42114101 rev.1 16 / 2.1.3 initialization this printer is initialized when the power is turned on or when the i-prime-n signal is input from the host side via the parallel interface. For the initialize operation, the rst-n signal is first output from the reset circuit to reset the mpus and lsis. When...

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    42114101 rev.1 17 / 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 2~8 µ s 500ns max. 2.1.4 interface control (1) parallel interface the parallel data input from the host to the interfaced lsi is latched to its internal...

  • Page 18

    42114101 rev.1 18 / (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 be met usb spec rev 1.1 fo...

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    42114101 rev.1 19 / 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 v v v v v v.

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    42114101 rev.1 20 / 2.1.5 print control print data is transmitted as parallel data (head1~head24) from lsi to print head. Lsi generates print timing and drive time. Print data mpu lsi driver head1-n~ head9-n print head a/d bus head1~ head9 control board print data head drive timing chart dt1 dt2 hea...

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    42114101 rev.1 21 / (d) simultaneous compensation of the number of impact pins the lsi is provided with the compensation table for each pin to make necessary compensation. Print compensation control the print compensation can be made as shown below: (a) voltage compensation (see 2.1.8 “alarm circuit...

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    42114101 rev.1 22 / 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 b1 b2 m slatch-n sdata-n s...

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    42114101 rev.1 23 / (1) space motor control the sp motor driver (mhm2025) drives the three-phase brushless motor based on the phase signal (spu, spv and spw) from the lsi and the speed instruction data from the mpu. The mpu can identify the current speed of the space motor by measuring through the l...

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    42114101 rev.1 24 / (2) encoder disk in the operation of the spacing motor, the phase-a and phase-b signals are generated when the encoder disk interrupts the photo sensor. The lsi divides these edge pulse signals in accordance with the print pitch, and sends the ipt signal to provide dot-on timing ...

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    42114101 rev.1 25 / 2.1.7 operation panel the clock synchronization opclk of lsi is used to input the switch data and output the led data through the operation panel control ic. Lsi operation panel control ic optxd opclk opclr-n oprxd 48 47 45 optd opck npa2 oprd command and data latch led driver sw...

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    42114101 rev.1 26 / note: from the illustration above, you can see that the command and the command response are output at the same time. This is because the bit 0 to bit 3 of oprxd are fixed so that the response can be returned before decoding the command. Optxd opclk oprxd opclr-n 1 2 3 2 3 1 6 7 ...

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    42114101 rev.1 27 / 2.1.8 alarm circuit (1) ac fuse open alarm (a) head drive time alarm circuit this circuit monitors the drive time using the hdalm signal interlocked with the overdrive signal of each drive circuit. If the drive time of any drive circuit exceeds the specified time, the drive fault...

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    42114101 rev.1 28 / (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/d port of the mpu to control the voltage. Mode and print control stop mode up...

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    42114101 rev.1 29 / (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 stop temp 105 ° c 95 ° c • when the temperature exceeds 105 ° ...

  • Page 30

    42114101 rev.1 30 / 2.1.9 power supply circuit this power supply circuit supplies the +3.3vdc, +5vdc, +12vdc, +42vdc, +50vdc and -8vdc. Sw ac fuse noise filter circuit trans- former power supply board control board rectifier converter rectifier regulation circuit +50v +12v +5v +5v -8v converter +3.3...

  • Page 31

    42114101 rev.1 31 / 2.2 mechanical operation 2.2.1 printhead mechanism and operation (see figure 2-2.) the printhead is a spring charged 24-pin driving head using a permanent magnet. It is attached to the carriage, which moves in parallel with the platen. Electrically, this unit is connected to the ...

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    42114101 rev.1 32 / (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. (b) when a signal for a c...

  • Page 33

    42114101 rev.1 33 / paper magnet assembly spacer yoke wire guide thermistor armature assembly print wire paper platen printhead print wire paper (1) when printing (2) when not printing figure 2-3.

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    42114101 rev.1 34 / 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. Items included in the spacing...

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    42114101 rev.1 35 / 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 adjusting lever is moved ...

  • Page 36

    42114101 rev.1 36 / c.W. Widens platen guide rail narrows printhead c.C.W. Adjusting cam adjusting screw adjusting screw adjusting gear idler gear adjusting lever printhead carriage shaft 1 4 5 3 2 range platen figure 2-5 range from 5 to 1 range from 1 to 5.

  • Page 37

    42114101 rev.1 37 / 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) (c) ribbon cartridge (1) ri...

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    42114101 rev.1 38 / drive gear ink tank ribbon cartridge figure 2-6.

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    42114101 rev.1 39 / 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) tractor feed unit (e) pr...

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    42114101 rev.1 40 / (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 change lever at the position...

  • Page 41

    42114101 rev.1 41 / change arm release shaft change lever change gear shaft rear switch switch lever bottom switch control power supply assy change lever tractor gear change gear reset spring idle gear (bottom tractor unit) platen gear (r) bottom rear platen top figure 2-7.

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    42114101 rev.1 42 / lf idel gear platen gear platen pressure roller stepping motor (lf motor) (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 gear...

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    42114101 rev.1 43 / change gear idle gear tractor gear platen gear paper (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 ...

  • Page 44

    42114101 rev.1 44 / (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 and pull tractor. The rot...

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    42114101 rev.1 45 / 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 optional pull tractor unit is ...

  • Page 46

    42114101 rev.1 46 / 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 feed unit is installed. W...

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    42114101 rev.1 47 / (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 cam installed to the front ...

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    42114101 rev.1 48 / change arm change lever platen release cam figure 2-13 rear top bottom.

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    42114101 rev.1 49 / 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 near end lever b rotates counter clockwise (ccw). At this time, the rear sensor lever rotates counterclockwise (ccw), the rear s...

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    42114101 rev.1 50 / (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 off position) to start printing at the front end of the sheet, without causing the sheet to crump...

  • Page 51

    42114101 rev.1 51 / rear bottom top sw1 sw2 bottom top rear 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 le...

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    42114101 rev.1 52 / (2) when using the continouos paper 1) set the change lever either to the rear side or the bottom side position. (see figure 2-13.) 2) set a sheet of paper either to the push tractor. 3) press the “ff/load” switch. 4) the lf motor starts its operation to feed the paper up to the ...

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    42114101 rev.1 53 / 2.2.8 paper park function (continuous paper) continuous sheets which have been inserted can be reversed automatically by using the “park” button on the operation panel. 1) press the “park” button on the operation panel. 2) reverse lf is started and paper is fed in reverse until p...

  • Page 54

    42114101 rev.1 54 / interface cable inlet ac cable ac receptacle ac input plug 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 ...

  • Page 55

    42114101 rev.1 55 / 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. 3-100 1 screwdriver 4 spring...

  • Page 56

    42114101 rev.1 56 / operation panel board driver board control/power supply board transformer assy upper cover assy printhead printer unit 3.3 disassembly/reassembly procedure this section explains the assembly replacement procedures according to the following disassembly system. [parts layout] figu...

  • Page 57

    42114101 rev.1 57 / [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 gear case assy 3.3.6 pc c...

  • Page 58

    42114101 rev.1 58 / 3 2 1 4 a 4 2 1 figure 3-2 figure 3-3 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 figure 3-2. (3) disconnect the printhead 2 from pc connector 3 . (4) to install, follow the removal steps in the reverse ord...

  • Page 59

    42114101 rev.1 59 / 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 60

    42114101 rev.1 60 / 4 3 2 1 3.3.3 pull-up roller assy (1) open the access cover 1 . (2) lift up the sheet guide assy 4 to remove. Note: please do after always remaining the sheet guide assy 4 when the pull-up roller assy 2 is installed and removed. (3) tilting the pull-up roller assy 2 toward the fr...

  • Page 61

    42114101 rev.1 61 / 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 twist to disengage claws of ...

  • Page 62

    4211410 rev.1 62 / 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 (4 places). Using a flat-b...

  • Page 63

    42114101 rev.1 63 / 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 the reverse order. Note on...

  • Page 64

    42114101 rev.1 64 / 3 4 1 2 a b d c 3 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 assy 3 fro...

  • Page 65

    42114101 rev.1 65 / 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 space rack 2 from the frame...

  • Page 66

    42114101 rev.1 66 / 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 , release the control board 2...

  • Page 67

    42114101 rev.1 67 / 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 claws (2 places) of roller...

  • Page 68

    42114101 rev.1 68 / 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) push in the lock levers ...

  • Page 69

    42114101 rev.1 69 / 2 4 4 2 1 5 3 3 sensor a 3.3.12 control board (tfs) (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...

  • Page 70

    42114101 rev.1 70 / a 1 lock a 2 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 driver board (...

  • Page 71

    42114101 rev.1 71 / 5 2 3 1 4 a 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 places) and re...

  • Page 72

    42114101 rev.1 72 / 7 8 8 3 6 5 4 1 2 a 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 screw...

  • Page 73

    42114101 rev.1 73 / 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 cable 7 . (5) remove two ...

  • Page 74

    42114101 rev.1 74 / 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 screw driver to remove...

  • Page 75

    42114101 rev.1 75 / 2 1 1 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 arrow) to remove. (5)...

  • Page 76

    42114101 rev.1 76 / 1 a 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) release claws a . (7) lift u...

  • Page 77

    42114101 rev.1 77 / 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) remove the tractor gear 1 ...

  • Page 78

    42114101 rev.1 78 / 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 the left to detach the rele...

  • Page 79

    42114101 rev.1 79 / 3.3.22 switch lever (1) remove the upper cover (see 3.3.4 (1) – (5)). (2) remove the control/power supply board. (see 3.3.15). (3) remove the change lever and gears (see 3.3.17). (4) remove the paper pan (see 3.3.19). (5) remove the rear pressure assy (see 3.3.21). (6) pull the s...

  • Page 80

    42114101 rev.1 80 / 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 minimize adjustment error..

  • Page 81

    42114101 rev.1 81 / after adjustment, mark the adjust composition with a red pen. Left right marking adjust cam 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 shal...

  • Page 82

    42114101 rev.1 82 / 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 clockwise direction (in dir...

  • Page 83

    42114101 rev.1 83 / touching 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 the contact touches...

  • Page 84

    42114101 rev.1 84 / 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 rear or bottom position, t...

  • Page 85

    42114101 rev.1 85 / 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: there shall be slight backl...

  • Page 86

    42114101 rev.1 86 / 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 time of measure- ment. 250...

  • Page 87

    42114101 rev.1 87 / 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 pinch the teeth of idle gear...

  • Page 88

    42114101 rev.1 88 / 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, be sure to apply lubricat...

  • Page 89

    42114101 rev.1 89 / 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) cleaning time remarks: 1) turn...

  • Page 90

    42114101 rev.1 90 / (5) lubrication point 1. Ribbon feed gear assy. 2. Space rack idle gear shaft (upper and lower) pm-b (0.006 ± 0.002g) drive gear shaft (upper and lower) pm-b (0.006 ± 0.002g) planetary gear shaft (upper and lower) em-30l-a approx. 30 (greasing range) approx. 35 (greasing range) e...

  • Page 91

    42114101 rev.1 91 / 3. Platen assy. Platen gear (l) grease the contact face of platen gear (l) and bias gear pm-b bias gear.

  • Page 92

    42114101 rev.1 92 / 4. Tractor driving mechanism 5. Tractor drive shaft surface of idle gear's teeth (circumference) em-30l-a tractor gear bearing portion em-30l-a sliding surface of change lever and gear em-30l-a sliding surface of reset spring and gear em-30l-a gear bearing portion em-30l-a reset ...

  • Page 93

    42114101 rev.1 93 / 6. Pressure roller release shaft protruding portion - 2 portions em-30l-a sliding portion of rear roller holder and release shaft cam surface (release shaft plane portion) em-30l-a rear roller holder shaft bearing portion of front roller holder and pressure roller em-30l-b slidin...

  • Page 94

    42114101 rev.1 94 / 7. Pull up roller assy. Gear and post em-30l-a all bearing portions of pull-up roller shaft and pull-up roller frame em-30l-b pull-up roller shaft pull-up roller frame.

  • Page 95

    42114101 rev.1 95 / 8. Main chassis assy. Grease portion (n: 3 portions, w: 5 portions) rear side em-30l-a grease portion at rib (n: 9 portions w: 13 portions) em-30l-a grease portion.

  • Page 96

    42114101 rev.1 96 / 9. Carriage assy. Nk2-10-sus bearing portion of guide roller em-30l-b.

  • Page 97

    42114101 rev.1 97 / 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 possible to those at the time th...

  • Page 98

    42114101 rev.1 98 / note: blink1 : 400ms on, 400ms off blink2 : 200ms on, 200ms off — : led is kept in current condition (no change) 6.3 lamp display (1) printer mode display table 6.2 (2) fault alram display when the printer detects any of the various alarm states, the information is displayed as s...

  • Page 99

    42114101 rev.1 99 / alarm category alarm led display alarm 10 12 15 17 20 prop utility prestige orator remarks troubleshooting main control alarm firmware detection alarm serial interface alarm mpu internal ram alarm program rom alarm ram on control board alarm cg rom alarm eeprom alarm wdt (watch d...

  • Page 100

    42114101 rev.1 100 / table 6.3 (2/2) alarm category alarm led display alarm 10 12 15 17 20 prop utility prestige orator lq 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, 200...

  • Page 101

    42114101 rev.1 101 / switch ac connector power supply board transformer centro-connector space motor lf motor fan motor print head control board operation panel board.

  • Page 102

    42114101 rev.1 102 / 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 40 39 38 37 36 35 34 33 28 27 26 25 24 23 22 21 32 31 30 29 n.C. Hd1 hd3 hd9 hd11 +50v +50v hd17 hd19 hd21 hd22 hd20 hd18 +50v +50v hd12 hd10 hd4 hd2 htemp n.C. Hd5 hd7 hd13 hd15 +50v +50v hd23 hd24 +50v +50v hd16 hd14 hd8 hd6 0...

  • Page 103

    42114101 rev.1 103 / cn4 1 2 3 4 lf motor (2) line feed motor resistance of each coil should be about 10.4 Ω . Signal connector pin number lf1 lf2 lf3 lf4 cn2 sp motor φ a photo sensor thermistor (5k Ω at 25 ° c) φ b 3 5 2 20 19 17 18, 22 (3) space motor resistance of each coil should be about 22.4 ...

  • Page 104

    42114101 rev.1 104 / 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). Remedied? No yes end doe...

  • Page 105

    42114101 rev.1 105 / no yes replace control board. Replace transformer assy. Remedied? No yes end replace power supply board. Control board cn2 20 1 pin no. 20 19 18 17 16 15 14 13 12 11 10 9 8 7 4 3 1 signal +50v ep +5v el +12v -8v (0v) (0v).

  • Page 106

    42114101 rev.1 106 / 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. Remedied? No yes end replace cont...

  • Page 107

    42114101 rev.1 107 / 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 space motor assy. Remedied? N...

  • Page 108

    42114101 rev.1 108 / paper platen ribon protector pull up roller cover 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...

  • Page 109

    42114101 rev.1 109 / 5 smearing/missing dots does alarm led blink and display alarm? No yes see tables 6.2 and 6.3 for troubleshooting information. Replace print head. Remedied? No yes end replace control board remedied? No yes end replace carriage cable or space motor assembly..

  • Page 110

    42114101 rev.1 110 / 6 faint or dark print is the print head gap set properly? Yes no adjust the print head gap (see section 5) remedied? No yes end replace print head. Remedied? No yes end replace control board remedied? No yes end replace ribbon feed mechanism.

  • Page 111

    42114101 rev.1 111 / 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 yes replace ribbon feed m...

  • Page 112

    42114101 rev.1 112 / 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 idle gear. Is the platen gea...

  • Page 113

    42114101 rev.1 113 / 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 114

    42114101 rev.1 114 / 10-1 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 suppress-ineffective” when the function is not required. Is the i/f rs232c? No yes to step 10-2 does t...

  • Page 115

    42114101 rev.1 115 / 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 parameters for rs232c in the m...

  • Page 116

    42114101 rev.1 116 / cn2 cn4 cn1 cn3 cn9 cn7 cn8 cn6 cn10 cn5 cn3 cn1 appendix a pcb layout pcb list (1) circuit board tpw (power supply board) (2) circuit board tfs (control board) (3) circuit board leop (operation panel board) (1) (2) (3).

  • Page 117

    42114101 rev.1 117 / 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/year. The following codes a...

  • Page 118

    42114101 rev.1 118 / table b-1 upper cover assy no. Part no. Description q'ty q'ty remarks required 1 42040801 upper cover (n) 1 2 for ml490 42040901 upper cover (w) 1 2 for ml491 2 51009409 sheet guide assy (n) 1 2 for ml490 51009510 sheet guide assy (w) 1 2 for ml491 3 42115401 access cover assy (...

  • Page 119

    42114101 rev.1 119 / 6 8 9 7 1 2 3 11 10 4 5 figure b-2 printer general assy.

  • Page 120

    42114101 rev.1 120 / table b-2 printer general assy no. Part no. Description q'ty q'ty remarks required 1 51902220 platen knob 1 1 2 42024002 power supply board (tpw) 1 9 3 42020002 control board (tfs) 1 9 4 55081109 operator panel board 1 3 (leop) 5 42116101 operation panel 1 2 6 ac cord for 120v 1...

  • Page 121

    42114101 rev.1 121 / 30 32 7 6 15 14 5 4 3 42 11 20 18 25 24 28 41 26 1 31 40 36 38 29 21 10 39 9 2 19 12 37 16 13 22 17 27 8 35 34 33 23 a a b b 39 figure b-3 printer unit.

  • Page 122

    42114101 rev.1 122 / table b-3 printer unit (1/2) no. Part no. Description q'ty q'ty remarks required 1 42114901 main chassis assy (n) 1 2 for ml490 42115001 main chassis assy (w) 1 2 for ml491 2 50809201 bottom paper end lever 1 1 3 50931301 pressure spring (f) 3 2 for ml490 5 4 for ml491 4 5334900...

  • Page 123

    42114101 rev.1 123 / table b-3 printer unit (2/2) no. Part no. Description q'ty q'ty remarks required 26 51022201 guide rail plate (n) 1 1 for ml490 51022301 guide rail plate (w) 1 1 for ml491 27 51238601 adjust cam 1 1 28 51114201 carriage shaft (n) 1 1 for ml490 51114202 carriage shaft (w) 1 1 for...

  • Page 124

    42114101 rev.1 124 / 9 12 11 1 13 3 7-1 14 5 6 7-2 10 8 figure b-4 carriage assy.

  • Page 125

    42114101 rev.1 125 / table b-4 carriage option assy no. Part no. Description q'ty q'ty remarks required 1 53349801 carriage frame set 1 2 2 3 53343201 back up roller holder assy 1 2 4 40493301 guide roller holder assy 1 2 5 6 42104201 space motor assy (24) 1 4 7-1 42252704 head cable (23) 1 5 ml490 ...

  • Page 126

    42114101 rev.1 126 / figure b-5 option spare parts [pull-tractor] [bottom-tractor] [i/f board] 3 2 1 4 5 6 7.

  • Page 127

    42114101 rev.1 127 / table b-5 option spare parts no. Part no. Description q'ty q'ty remarks required 1 50098001 pull and bottom 1 2 tractor assy (l) 2 50097901 pull and bottom 1 2 tractor assy (r) 3 53077201 tractor cover assy (n) 1 3 for ml490 53077301 tractor cover assy (w) 1 3 for ml491 4 519023...

  • Page 128

    42114101 rev.1 128 / 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 serial interface board is cap...

  • Page 129

    42114101 rev.1 129 / 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 75188 75189 figure c-1 block ...

  • Page 130

    42114101 rev.1 130 / 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 yes yes no dsr high? Yes s...

  • Page 131

    42114101 rev.1 131 / 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 store 40 h in buffer. Yes y...

  • Page 132

    42114101 rev.1 132 / 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, operate the printer in the s...

  • Page 133

    42114101 rev.1 133 / 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) select and (into) busy signals...

  • Page 134

    42114101 rev.1 134 / 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 q3. Yes is the level of a...

  • Page 135

    42114101 rev.1 135 / 135 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 connector figure c-9 test co...