Oki ML420 Maintenance Manual
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Oki ML420 Maintenance Manual

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ML420/421

Maintenance Manual

For Rev "E0" and Higher
032411A
Oki Data CONFIDENTIAL

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Summary of Contents for Oki ML420

  • Page 1: Maintenance Manual

    ML420/421 Maintenance Manual For Rev "E0" and Higher 032411A Oki Data CONFIDENTIAL...
  • Page 2 Nothing contained herein shall be construed as conferring by estoppel, implication or otherwise any license or right under any patent or trademark of Oki Data, Oki Electric Industry Co., Ltd. ("Oki Electric"), or any third party. Except as provided above nothing contained herein shall be construed as conferring any license or right under any Oki Data copyright.
  • Page 3 Oki Data CONFIDENTIAL 42113931TH Rev.1...

  • Page 4: Table Of Contents

    Oki Data CONFIDENTIAL Contents 1. CONFIGURATION ....................6 Standard Printer Configuration .................... 6 Options ..........................7 2. THEORY OF OPERATION ..................9 Electrical Operation ......................9 2.1.1 Summary ......................... 9 2.1.2 SOC and the Peripheral Circuit ................9 2.1.3 Initialization ......................12 2.1.4...
  • Page 5 Oki Data CONFIDENTIAL 3.3.20 Rear Tractor Assy ....................73 3.3.21 Rear Pressure Assy ....................74 3.3.22 Switch Lever ......................75 4. ADJUSTMENT ....................76 5. CLEANING AND LUBRICATION ...............85 Cleaning ..........................85 Lubrication ......................... 86 6. TROUBLESHOOTING AND REPAIR ..............93 Items to Check Before Repair .................... 93 Troubleshooting Table .......................

  • Page 6: Configuration

    Oki Data CONFIDENTIAL CONFIGURATION Standard Printer Configuration This printer consists of the following assemblies: Platen knob Sheet guide assy Access cover assy Upper cover Pull-up roller assy Power supply unit Operation panel assy Main control PCB Main chassis assy Figure 1-1 Configuration...

  • Page 7: Options

    Oki Data CONFIDENTIAL Options Cut sheet feeder unit (CSF) (Narrow and wide versions available) Single-bin CSF Attachment assy Pull-tractor assy 42113931TH Rev.1...
  • Page 8 Oki Data CONFIDENTIAL Bottom push tractor unit Roll paper stand (Narrow only) Option I/F Board • RS232C Serial interface board • OKI LAN board 42113931TH Rev.1...

  • Page 9: Theory Of Operation

    • Built-in CPU core (ARM7TDMI) • SPAM 4M bit • With built-in USB controller • With built-in UART function • AD converter x 4ch DA converter x 2ch OKI of other peripheral circuitry is original though CPU core uses ARM7TDMI. 42113931TH Rev.1...
  • Page 10 Oki Data CONFIDENTIAL OPTION CSF or ROLL 48Mhz PAPER STAND ADDRESS FLASH OPERATION PANEL PCB DATA RESET-N HEAD ALARM ALARM-P CIRCUIT PRINT HEAD DRIVE PARARREL HEAD IEEE1284 CIRCUIT DERIVER IC HD TEMP OPTION I/F RS232C FUSE SP ALARM (SYSTEM ON CHIP)
  • Page 11 Oki Data CONFIDENTIAL Program ROM (external FLASH ROM) The program to make the printer work is stored in FLASH ROM as external ROM. FLASH ROM that can be installed is 64Mbit(16 x 4096k) or less. The access timing of the outline to FLASH ROM is shown in the following.

  • Page 12: Initialization

    Oki Data CONFIDENTIAL 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 SOC and Flash ROM.

  • Page 13: Interface Control

    Oki Data CONFIDENTIAL 2.1.4 Interface Control Parallel Interface The parallel data input from the host to the interfaced SOC is latched to its internal register at the falling edge of the STROBE-N signal. At the same time, the SOC sets the BUSY signal to the high level to inform the host that the data is being processed, and outputs the RXD signal to inform the SOC of data reception.
  • Page 14 Oki Data CONFIDENTIAL Universal Serial Bus (USB) Universal Serial Bus Specification Revision 2.0 (Full speed) compliance. Connector • Printer Side : “B” Receptacle (Upstream Input to the USB Device) • Cable Side : Series “B” Plug Cable • Cable Length : Approx 1.8m (A cable must be met USB Spec Rev 1.1 for...
  • Page 15 Oki Data CONFIDENTIAL Signal Level • Input / Output Level Parameter Symbol Min. Max. Units Input Levels : High (driven) High (floating) Output Levels : High (driven) Output Signal Crossover Voltage 15 / 42113931TH Rev.1...

  • Page 16: Print Control

    Oki Data CONFIDENTIAL 2.1.5 Print Control Print data is transmitted as parallel data (HD01~HD09) from SOC to print head. SOC generates print timing and drive time. Main Control PCB Print Head DRIVER Print Data Print Data HD01-P~ HEAD1-N~ HD09-P HEAD9-N...
  • Page 17 Oki Data CONFIDENTIAL Print Compensation Control The print compensation can be made as shown below: Voltage compensation (See 2.1.8 “Alarm Circuit.”) Temperature compensation (See 2.1.8 “Alarm Circuit.”) Pin stroke compensation Platen Print Head Pin 1, 2 As shown in the drawing left, the stroke length up to the platen is different for each pin.

  • Page 18: Sp/Lf Motor Fan Control

    Oki Data CONFIDENTIAL 2.1.6 SP/LF Motor FAN Control Space motor control The SP motor driver (BD6206FS) drives the three-phase brushless motor based on the phase signal (SPU-P, SPV-P and SPW-P) from the speed instruction data from the SOC. The SOC can identify the current speed of the space motor by measuring through the pulse length of the output (øA, øB) of the slit encoder included in the space motor.
  • Page 19 Oki Data CONFIDENTIAL 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 SOC divides these edge pulse signals in accordance with the print pitch, and sends the IPT signal to provide dot-on timing and carriage position detection timing.
  • Page 20 Oki Data CONFIDENTIAL (4) FAN control The motor that uses it is DC brushless FAN motor. The outline circuit composition is as follows. On/off is controlled by control signal MAINFANON-P from SOC. When the motor stops by some factors when the motor rotates, the FANALM-P signal is sent from FAN, and this signal is recognized with SOC and it is assumed fan alarm.

  • Page 21: Operation Panel

    Oki Data CONFIDENTIAL 2.1.7 Operation Panel The clock synchronization OPCLK of SOC is used to input the switch data and output the LED data through the operation panel control IC. Operation panel control IC OPTXD SWI1 OPCLK SWI4 Command LED driver...
  • Page 22 Oki Data CONFIDENTIAL 22 / 42113931TH Rev.1...

  • Page 23: Alarm Circuit

    Oki Data CONFIDENTIAL 2.1.8 Alarm Circuit Head drive time alarm circuit This circuit monitors the drive time using the DT1ALM1-N 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 alarm circuit sends an ALM-P signal to POWER SUPPLY UNIT.
  • Page 24 Oki Data CONFIDENTIAL Overheat alarm Head overheat alarm The voltage of the output HTEMP signal of the thermistors, one of which is contained in the print head is monitored by the A/D port of the SOC to control the voltage.
  • Page 25 Oki Data CONFIDENTIAL 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 SOC to control the voltage. Temp Stop 105°C...

  • Page 26: Power Supply Unit

    Oki Data CONFIDENTIAL 2.1.9 Power Supply Unit This power supply unit is a switching power supply. This power supply unit supplies the +5VDC, +40VDC. AC Fuse Electric Filter +40VDC current circuit circuit circuit control +5VDC circuit circuit Alarm ALM-P circuit...
  • Page 27 Oki Data CONFIDENTIAL (4) Alarm function (See 2.1.8) When an ALM-P signal has been output from the control unit, this function suspends switching and cuts off all output. This state is maintained after the power switch is turned off until the power supply resumes about 30 seconds later.

  • Page 28: Mechanical Operation

    Oki Data CONFIDENTIAL 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 unit is connected to the control circuits through the Main Control PCB.
  • Page 29 Oki Data CONFIDENTIAL Operation of printhead (See Figure 2-3.) 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 30 Oki Data CONFIDENTIAL Paper Printhead Print wire Platen When printing Paper Armature assembly Thermistor Print wire Wire guide Yoke Magnet assembly Spacer When not printing Paper Figure 2-3 30 / 42113931TH Rev.1...

  • Page 31: Spacing Operation

    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.

  • Page 32: Head Gap Adjusting

    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 adjusting lever is moved creating a fine gap adjustment.
  • Page 33 Oki Data CONFIDENTIAL Platen Range Carriage shaft Printhead Adjusting screw Adjusting lever Adjusting gear Idler gear Narrows Range from Printhead Adjusting screw Adjusting cam C.C.W. Platen Guide rail Widens Range from C.W. Figure 2-5 33 / 42113931TH Rev.1...

  • Page 34: Ribbon Drive

    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: Ribbon drive gear assembly Ribbon gear (space motor)

  • Page 35: Paper Feed Operation

    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: Pulse motor with gears...
  • Page 36 Oki Data CONFIDENTIAL Cut sheet and continuous sheet switching mechanism (See Figure 2-7.) Three different paper paths can be selected and set by the change lever. 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 marked TOP.
  • Page 37 Oki Data CONFIDENTIAL Senser PCB Switch lever Bottom switch Change gear shaft Rear switch Change lever Release shaft Change arm Platen BOTTOM Change lever REAR Tractor gear Change gear Platen gear (R) Reset spring Idle gear (Bottom tractor unit) Figure 2-7 37 / 42113931TH Rev.1...
  • Page 38 Oki Data CONFIDENTIAL 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.
  • Page 39 Oki Data CONFIDENTIAL 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 rotate through a sheet feeder shaft, feeding the continuous paper.
  • Page 40 Oki Data CONFIDENTIAL 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.
  • Page 41 Oki Data CONFIDENTIAL Pull tractor mechanism (option) (See Figure 2-11.) Bottom feed of continuous sheets is possible only when an optional pull tractor unit is installed. The rotation of the platen is transmitted to the idle gear of the pull tractor unit through the platen gear at the left end of the platen.
  • Page 42 Oki Data CONFIDENTIAL 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. When the platen rotates, the rotational force of the platen is transmitted through the tractor idle gear and the tractor change gear to the tractor drive gear of the bottom push tractor, and the sheet of paper is fed in to the print start position.
  • Page 43 Oki Data CONFIDENTIAL 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 release gear shaft changes, and the open and close of the pressure roller.
  • Page 44 Oki Data CONFIDENTIAL Change lever Release cam Platen Front release gear arm BOTTOM REAR Figure 2-13 44 / 42113931TH Rev.1...

  • Page 45: Paper Detection Mechanism

    Oki Data CONFIDENTIAL 2.2.6 Paper Detection Mechanism (See Figure 2-14.) 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 sensor lever and pulls out of the rear and top paper end sensor to detect that the sheet is provided.
  • Page 46 Oki Data CONFIDENTIAL 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 crumple or curl up.

  • Page 47: Automatic Sheet Feed

    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] When using the cut sheet Set the change lever to the TOP position.
  • Page 48 Oki Data CONFIDENTIAL When using the continouos paper Set the change lever either to the rear side or the bottom side position. (See Figure 2-16.) Set a sheet of paper either to the push tractor or the bottom tractor. Press the “FF/LOAD” switch.

  • Page 49: Paper Park Function (Continuous Paper)

    Oki Data CONFIDENTIAL 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. Press the “PARK” button on the operation panel. Reverse LF is started and paper is fed in reverse until paper end occurs or 19 inches maximum have been fed.

  • Page 50: Assembly/Disassembly

    Oki Data CONFIDENTIAL 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 of the removal procedure.

  • Page 51: Service Tools

    Oki Data CONFIDENTIAL 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 Service Tool Q’ty Remarks No. 1-100 Phillips Screws screwdriver 2.6 mm No. 2-200 Phillips...

  • Page 52: Disassembly/Reassembly Procedure

    Oki Data CONFIDENTIAL Disassembly/Reassembly Procedure This section explains the assembly replacement procedures according to the following disas- sembly system. [Parts Layout] Upper cover assy AC inlet and AC switch Power supply unit Printhead Sensor PCB Main Control PCB Operation panel PCB...
  • Page 53 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 54: Printhead

    Oki Data CONFIDENTIAL 3.3.1 Printhead Open the access over. Pull up and rotate the head clamp 1 to unclamp the printhead 2 as shown fig. 3.3.1. Disconnect the printhead 2 from PC connector 3. To install, follow the removal steps in the reverse order.

  • Page 55: Ribbon Protector

    Oki Data CONFIDENTIAL 3.3.2 Ribbon Protector Remove the printhead (see 3.3.1). Open the pull-up roller cover 1. Raise and remove the ribbon protector 2. To install, follow the removal steps in the reverse order. 55 / 42113931TH Rev.1...

  • Page 56: Pull-Up Roller Assy

    Oki Data CONFIDENTIAL 3.3.3 Pull-up Roller Assy Open the access cover 1. Lift up the sheet guide Assy 4 to remove. Tilting the pull-up roller Assy 2 toward the front, remove from the shaft of platen Assy To install, follow the removal steps in the reverse order.

  • Page 57: Upper Cover Assy, Access Cover Assy And Sheet Guide Assy

    Oki Data CONFIDENTIAL 3.3.4 Upper Cover Assy, Access Cover Assy and Sheet Guide Assy Pull off the platen knob 1. Turn the change lever 2 toward the bottom position. Insert a flat-blade screwdriver into grooves (5 places) (4 places for narrow type) of frame and twist to disengage claws of upper cover 3.

  • Page 58: Gear Case Assy

    Oki Data CONFIDENTIAL 3.3.5 Gear Case Assy Remove the printhead (see 3.31). Remove the upper cover (see 3.3.4 (1) – (5)). Move the carriage Assy to right hand side, remove two screws 1, then the space motor 2. Disconnect a carriage cable.

  • Page 59: Pc Connector

    Oki Data CONFIDENTIAL 3.3.6 PC Connector Remove the printhead (see 3.3.1). Remove the upper cover (see 3.3.4 (1) – (5)). Remove the gear case Assy (see 3.3.5). Remove the PC connector 1 from the space motor Assy 2. To install, follow the removal steps in the reverse order.

  • Page 60: Space Motor, Guide Roller Assy

    Oki Data CONFIDENTIAL 3.3.7 Space Motor, Guide Roller Assy Remove the printhead (see 3.3.1). Remove the upper cover (see 3.3.4 (1) – (5)). Remove the gear case Assy (see 3.3.5). Remove the PC connector (see 3.3.6). Remove screw 2, then the guide roller Assy 3 from the space motor 1.

  • Page 61: Space Rack

    Oki Data CONFIDENTIAL 3.3.8 Space Rack Remove the printhead (see 3.3.1). Remove the upper cover (see 3.3.4 (1) – (5)). Remove the gear case Assy (see 3.3.5). Remove the space motor (see 3.3.7). Remove the spring 1. Disengage the claw on left side of space rack 2 from the frame, and remove the space rack 2 in upper direction.

  • Page 62: Carriage Cable

    Oki Data CONFIDENTIAL 3.3.9 Carriage Cable Remove the printhead (see 3.3.1). Remove the upper cover (see 3.3.4 (1) – (5)). Remove the gear case Assy (see 3.3.5). Remove the space motor (see 3.3.7). Remove the space rack (3.3.8). Remove three screws 1, release the Main Control PCB 2 by lifting clamp 9, and disconnect cable from connector 3, 4, 5, 6, 7.

  • Page 63: Backup Roller Holder Assy

    Oki Data CONFIDENTIAL 3.3.10 Backup Roller Holder Assy Remove the printhead (see 3.3.1), Remove the upper cover (see 3.3.4 (1) – (5)). Remove the gear case Assy (see 3.3.5). Remove the space motor (see 3.3.7). Remove the backup roller spring 2.

  • Page 64: Platen Assy

    Oki Data CONFIDENTIAL 3.3.11 Platen Assy Remove the printhead (see 3.3.1). Remove the ribbon protector (see 3.3.2). Remove the pull-up roller Assy (see 3.3.3). Remove the upper cover (see 3.3.1 (1) – (5)). Turn the change lever 1 to the bottom position.

  • Page 65: Main Control Pcb

    Oki Data CONFIDENTIAL 3.3.12 Main Control PCB Remove the upper cover (see 3.3.4 (1) – (5)). Remove three screws 1, and release the Main Control PCB 2 by lifting clamp 4. Disconnect all cables from Main Control PCB 2. To install, follow the removal steps in the reverse order.

  • Page 66: Lf Motor

    Oki Data CONFIDENTIAL 3.3.13 LF Motor Remove the printhead (see 3.3.1). Remove the ribbon protector (see 3.3.2). Remove the pull-up roller Assy (see 3.3.3). Remove the upper cover (see 3.3.4 (1) – (5)). Remove the platen Assy (see 3.3.11). Remove the Main Control PCB (see 3.3.12).

  • Page 67: Operation Panel Pcb

    Oki Data CONFIDENTIAL 3.3.14 Operation Panel PCB Remove the upper cover (see 3.3.4 (1) – (5)). Disconnect the cable 1 from connector 3 of Main Control PCB 2. Disengage claws on both sides from the frame, and remove the operation panel 4.

  • Page 68: Power Supply Unit, Sensor Pcb

    Oki Data CONFIDENTIAL 3.3.15 Power Supply Unit, Sensor PCB Risk of Electric Shock There is a risk of electric shock during replacement of the power supply. Use insulating gloves or avoid direct contact with any conducting part of the power supply, and caution should be exercised during replacement.

  • Page 69: Ac Inlet And Ac Switch

    Oki Data CONFIDENTIAL 3.3.16 AC inlet and AC Switch Remove the upper cover (see 3.3.4 (1) – (5)). Remove AC inlet 1 and AC switch 2 from the frame guide. Disconnect the cable 3 from the connector 4 on the Power Supply Unit 5.

  • Page 70: Change Lever And Gears

    Oki Data CONFIDENTIAL 3.3.17 Change Lever and Gears Remove the upper cover (see 3.3.4 (1) – (5)). Remove the reset spring 1, then remove the idle gear 2, the tractor gear 4 and the change gear 5. Push back the protrusion of the Change Gear Shaft 6 with a flatblade screw driver to remove the change lever 3.

  • Page 71: Carriage Shaft

    Oki Data CONFIDENTIAL 3.3.18 Carriage Shaft Remove the printhead (see 3.3.1). Remove the upper cover (see 3.3.4 (1) – (5)). Remove the Main Control PCB (see 3.3.12). Remove the FG plate (L) 2. Slide the carriage shaft 1 to the left side (in the direction of the arrow) to remove.

  • Page 72: Paper Pan

    Oki Data CONFIDENTIAL 3.3.19 Paper Pan Remove the printhead (see 3.3.1). Remove the ribbon protector (see 3.3.2). Remove the pull-up roller assy (see 3.3.3). Remove the upper cover assy (see 3.3.4 (1) – (5)). Remove the platen assy (see 3.3.11).

  • Page 73: Rear Tractor Assy

    Oki Data CONFIDENTIAL 3.3.20 Rear Tractor Assy Remove the printhead (see 3.3.1). Remove the ribbon protector (see 3.3.2). Remove the pull-up roller assy (see 3.3.3) Remove the upper cover (see 3.3.4 (1) – (5)). Remove the reset spring (see 3.3.17 (3)) Remove the tractor gear 1.

  • Page 74: Rear Pressure Assy

    Oki Data CONFIDENTIAL 3.3.21 Rear Pressure Assy Remove the upper cover (see 3.3.4 (1) – (5)). Remove the change lever and gears (see 3.3.17). Remove the paper pan (see 3.3.19). Remove the rear pressure roller 1. Rotate the release shaft 2 and move it to the left to detach the release shaft 2.

  • Page 75: Switch Lever

    Oki Data CONFIDENTIAL 3.3.22 Switch Lever Remove the upper cover (see 3.3.4 (1) – (5)). Remove the Power Supply Assy (see 3.3.15). Remove the change lever and gears (see 3.3.17). Remove the paper pan (see 3.3.19). Remove the rear pressure assy (see 3.3.21).

  • Page 76: Adjustment

    Oki Data CONFIDENTIAL ADJUSTMENT Be sure to carry out this adjustment with the printer mechanism mounted on the lower cover. 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 77 Oki Data CONFIDENTIAL Item Specification Drawing Adjustment method 4–1–1 Gap between the plat- It shall be measured en and the print head at 3 points: the left end, the center and 1) Parallelism the right end of the justment Variation of platen.
  • Page 78 Oki Data CONFIDENTIAL Item Specification Drawing Adjustment method Note 1) Adjust lever The head gap shall be measured with the change lever set to rear position. Adjust gear Note 2) The head gap shall be measured positioning Adjust spring the platen gear (R) Adjust craw on the top.
  • Page 79 Oki Data CONFIDENTIAL Item Specification Drawing Adjustment method Adjust lever Gap between the con- 0.3mm or more Confirm followings. tact and the monitor Make sure that the gap between the con- tact and the motor PCB is 0.3 mm or more.
  • Page 80 Oki Data CONFIDENTIAL Item Specification Drawing Adjustment method 4–2 between 1±0.5 Confirm followings. platen and the paper (1) When the change lever is set at Change lever Friction position, the gap between Bottom Rear the platen and the paper pan at the rear side shall be 1±0.5mm.
  • Page 81 Oki Data CONFIDENTIAL Item Specification Drawing Adjustment method 4–4–1 Rotation of the push To confirm: tractor The tractor gear shall rotate smoothly when the change lever is set at Friction posi- tion. Change lever (Center friction) Push tractor Tractor gear Slight backlash 4–4–2...
  • Page 82 Oki Data CONFIDENTIAL Item Specification Drawing Adjustment method 4–5–1 Ribbon feed To confirm: Ribbon shall be fed smoothly when the carriage is moved from side to side. Ribbon feeding Ribbon 4–5–2 Running load to spac- 250g or less To confirm:...
  • Page 83 Oki Data CONFIDENTIAL Item Specification Drawing Adjustment method 4–6 Engagement of the To confirm: double gear and the LF The idle gear of the motor idle gear of the LF motor and the Platen Assy. platen gear (L) and the bias gear of the...
  • Page 84 Oki Data CONFIDENTIAL Item Method 4–7 Resetting Menu to the The factory default setting for the Printer. Factory Default. To reset the printer to the factory default: (1) Turn the printer off. (2) Press and hold down the SEL key and QUIET key while turning on the printer.

  • Page 85: Cleaning And Lubrication

    Oki Data CONFIDENTIAL CLEANING AND LUBRICATION Cleaning [Cautions] Be sure to turn OFF the AC POWER switch before cleaning. Remove the AC power cord from the printer. Avoid dust inside the printer mechanism when cleaning. If a lubricated part has been cleaned, be sure to apply lubricating oil to that portion after cleaning.

  • Page 86: Lubrication

    Oki Data CONFIDENTIAL 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. Cleaning time Remarks: 1) Turn off the power before cleaning.
  • Page 87 Oki Data CONFIDENTIAL Lubrication point Ribbon feed gear Assy. Planetary gear shaft Drive gear shaft (upper and lower) (upper and lower) PM-B (0.006–0.002g) EM-30L-A Idle gear shaft (upper and lower) PM-B (0.006–0.002g) Space rack Space rack Rack upper side Approx. 35 (greasing range) EM-30L-A Approx.
  • Page 88 Oki Data CONFIDENTIAL Platen Assy. Grease the contact face of platen gear (L) and bias gear Bias gear PM-B Platen gear (L) 88 / 42113931TH Rev.1...
  • Page 89 Oki Data CONFIDENTIAL Tractor driving mechanism Change lever Tractor gear bearing portion EM-30L-A Change arm Idle gear teeth EM-30L-A Reset spring Sliding surface of Sliding surface of change lever and gear Gear bearing portion reset spring and gear EM-30L-A EM-30L-A...
  • Page 90 Oki Data CONFIDENTIAL Pressure roller Change arm Release shaft Support spring Contact portion of support spring and shaft EM-30L-A Contact portion of rear Front pressure roller holder and shaft EM-30L-A Controller holder Sliding portion of release shaft Sliding portion of rear roller holder...
  • Page 91 Oki Data CONFIDENTIAL 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 91 / 42113931TH Rev.1...
  • Page 92 Oki Data CONFIDENTIAL Main chassis Assy. Grease portion (N: 3 portions) rear side EM-30L-A Grease portion at rib (N: 9 portions) EM-30L-A Grease portion Carriage Assy. NK2-10-SUS Bearing portion of guide roller EM-30L-B 92 / 42113931TH Rev.1...

  • Page 93: Troubleshooting And Repair

    Oki Data CONFIDENTIAL TROUBLESHOOTING AND REPAIR Items to Check Before Repair Check the inspection items specified in the instruction manual. Find out as many details of the trouble as possible from the customer. Inspect in the conditions as close as possible to those at the time the trouble occurred.

  • Page 94: Lamp Display

    Oki Data CONFIDENTIAL Lamp Display Printer mode display Table 6.2 LED CONDITION TROUBLE ALARM ALARM CONTENTS CATEGORY SHOOTING ALARM MENU 10CPI 15CPI From, cut sheet or bottom — — — Set New paper. Paper end alarm paper end Change lever is set to TOP •...
  • Page 95 Oki Data CONFIDENTIAL 95 / 42113931TH Rev.1...
  • Page 96 Oki Data CONFIDENTIAL 96 / 42113931TH Rev.1...
  • Page 97 Oki Data CONFIDENTIAL 97 / 42113931TH Rev.1...

  • Page 98: Connection Circuit Check For Printhead And Sp/Lf Motor

    Oki Data CONFIDENTIAL Connection Circuit Check for Printhead and SP/LF Motor Printhead Signal Connector pin number HEAD1 HEAD2 HEAD4 HEAD6 HEAD8 Thermistor HTEMP (5KΩ at 25°C) +50V +50V +50V HEAD9 HEAD7 HEAD5 HEAD3 98 / 42113931TH Rev.1...
  • Page 99 Oki Data CONFIDENTIAL Line Feed Motor Resistance of each coil should be about 10.4Ω. Signal Connector pin number motor Space Motor Resistance of each coil should be about 22.4Ω. Signal Connector pin number SP-U SP-V Motor SP-W Photo φA sensor φB...

  • Page 100: Troubleshooting Flow Chart

    Oki Data CONFIDENTIAL Troubleshooting flow chart Power is not supplied. Is the AC cable connected correctly? Connect the AC cable correctly. Are the voltage setting pins on the power supply unit configured correctly? 1 to next step Does the device operate when restoring power supply after turning the power switch off and changing the settings to ones suited to the AC voltage used? 1 Remove CN101 on power supply unit.
  • Page 101 Oki Data CONFIDENTIAL No spacing operation (The alarm LED Blinks) Is carriage assembly binding or jammed? Check around space motor to repair the mechanism of space belt, idle pulley, ribbon feed mechanism, and carriage frame etc. Replace Space motor assy.
  • Page 102 Oki Data CONFIDENTIAL Homing does not end normally Check around space motor to repair the mechanism. (Space rack, ribbon feed assembly back up roller, carriage frame, support protector and ribbon protector.) Remedied? Replace Space motor assy. Replace Space motor assy.
  • Page 103 Oki Data CONFIDENTIAL Paper jam while paper insertion Jam 1 Check the ribbon protector. Check the pull up roller cover is closed properly. Pull up roller cover Platen Ribon Protector Paper Jam 2 (wrinkled paper) Check around pressure roller mechanism.
  • Page 104 Oki Data CONFIDENTIAL Smearing/missing dots Does ALARM LED blink and display alarm? See Tables 6.2 and 6.3 for troubleshooting information. Replace Printhead. Remedied? Replace the Main Control PCB. Remedied? Replace Carriage cable or Space motor assy. 104 / 42113931TH Rev.1...
  • Page 105 Oki Data CONFIDENTIAL Faint or dark print Is the print head gap set properly? Adjust the printhead gap (see section 5). Remedied? Replace Printhead. Remedied? Replace the Main Control PCB. Remedied? Replace Ribbon feed mechanism. 105 / 42113931TH Rev.1...
  • Page 106 Oki Data CONFIDENTIAL Ribbon feed trouble Remove the ribbon cartridge. Move carriage to left and right. Does the ribbon drive shaft rotate? Change Ribbon cartridge. Remove Ribbon feed mechanism. Move carriage to left and right. Does the ribbon drive shaft rotate? Replace Ribbon feed mechanism.
  • Page 107 Oki Data CONFIDENTIAL Line feed trouble Turn the power off, and rotate the platen manually. Does the platen rotate smoothly? Is the platen gear (L) broken? Replace Platen assembly. Is the LF motor idle gear broken? Replace the LF motor assembly or LF idle gear.
  • Page 108 Oki Data CONFIDENTIAL Malfunction of switch on operation panel Is the CN1 of Operation panel connected to the OP on the Main Control PCB? Connect the cable properly. Replace the Operation panel PCB. Remedied? Replace the Main Control PCB. 108 /...
  • Page 109 Oki Data CONFIDENTIAL Data receiving failure Is the SEL LED blinking? 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?
  • Page 110 Oki Data CONFIDENTIAL 10-2 (RS232C I/F) Printer I/F pin assignment. Is the correct cable used? 2 pin, 3 pin, 11 pin, 20 pin, Change I/F cable. 6 pin. Is ALARM LED blinking? See tables 6.2 and 6.3 for the troubleshooting.

  • Page 111: Appendix Apcb Layout

    Oki Data CONFIDENTIAL Appendix A PCB LAYOUT PCB list Main Control PCB Operation Panel PCB Power Supply Unit Sensor PCB Main Control PCB LFMOT Board – EXB- EXB- Note. Stamp 1 Note. Stamp 2 Note. Stamp Stamp 1 *1) Stamp 2...

  • Page 112: Appendix Brs-232C Serial Interface Board (Option)

    Oki Data CONFIDENTIAL Appendix B RS-232C SERIAL INTERFACE BOARD (OPTION) 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 capable of transmitting and receiving simultaneously at speeds up to 19,200 bits per second.
  • Page 113 Oki Data CONFIDENTIAL Circuit Description A block diagram is shown in Figure B-1. RSDV1 (HIN202E) RSDV2 (HIN202E) RSCONECT-N Control board and connection terminal Figure B-1 Block Diagram 2.2.1 Operation at power on It becomes possible to use the RS232C board because SOC of the Main Control PCB recog- nizes that the RSCONECT-N signal is connected with OV when the power supply is turned on.

  • Page 114: Communication Procedure Flowchart

    Oki Data CONFIDENTIAL Communication Procedure Flowchart 2.3.1 Mode a Ready/Busy Received one character ? is DSR signal valid ? DSR signal is High ? Parity Error ? Store 0x40("@") in buffer. Framing Error ? Store 0x3f("?") in buffer. Overrun Error ? Store 0x21("!")
  • Page 115 Oki Data CONFIDENTIAL 2.3.2 Mode b X-ON/X-OFF Received one character ? is DSR signal valid ? DSR signal is High ? Parity Error ? Store 0x40("@") in buffer. Framing Error ? Store 0x3f("?") in buffer. Overrun Error ? Store 0x21("!") in buffer.
  • Page 116 Oki Data CONFIDENTIAL TROUBLESHOOTING FLOWCHART 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 same situation as that at the time of trouble occurrence to see if the same trouble occurs again.
  • Page 117 Oki Data CONFIDENTIAL Local Test 3.3.1 Circuit test mode 3.3.1.1 Setting Diagnostic test (set by menu) Test connector Connect the test connector shown in Figure B-9 to the interface connector Equivalent to Cannon DB-25P Figure B-9 Test Connector Connection Diagram 3.3.1.2 Function...

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