Oki ML490 Series Maintenance Manual Download

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42114101 Rev.1

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ML490/491 PRINTER

Maintenance Manual

ODA

Summary of Contents for ML490 Series

Page 1: ...42114101 Rev 1 1 135 ML490 491 PRINTER Maintenance Manual ODA...

Page 2: ...42114101 Rev 1 2...

Page 3: ...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...

Page 4: ...d operation 39 2 2 6 Paper detection mechanism See Figure 2 14 49 2 2 7 Automatic sheet feed 51 2 2 8 Paper park function continuous paper 53 3 ASSEMBLY DISASSEMBLY 54 3 1 Precaution for Parts Replace...

Page 5: ...and SP LF Motor 102 6 5 Troubleshooting flow chart 104 APPENDIX A PCB LAYOUT 116 APPENDIX B SPARE PARTS LIST 117 APPENDIX C RS 232C SERIAL INTERFACE BOARD OPTION 128 1 GENERAL 128 2 OPERATION DESCRIP...

Page 6: ...onfiguration 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...

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...

Page 9: ...r and the peripheral circuit 1 Microprocessor This processor is a CMOS single chip computer with integrated peripheral device functions and a 16 bit MPU core all OKI original architecture The processo...

Page 10: ...ircuit 50 volt 12 volt 5 volt 42V 8V 3 3V 5VS Reset circuit I F IPT Print IPT EEPROM 1Kbits Microproce ssor ADDRESS Serial Serial ROM 8Mbit Max 16Mbit AD BUS DRAM 4Mbit LSI RESET 5VD POWLEV Fuse 42 V...

Page 11: ...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 program ROM is assigned to the program...

Page 12: ...ffer The following shows the examples of the memory access operation Clockout is provided when the original excitation is selected A0 A8 CAS N RAS N UCAS N LCAS N WR N RD N WRH N WRL N RAM MPU P03 CS1...

Page 13: ...er 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 acces...

Page 14: ...ows the memory access operation 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 tCS PRE O PE EECS P EECLK...

Page 15: ...s 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 N ALE P RDN WRL LSIC RAS 1 P07 RAS 0 RAS N Clocko...

Page 16: ...reset the MPU The program here sets the mode of the LSI including the MPU checks the memories ROMs and RAMs then carries out carriage homing and determines the LF motor phase Finally the program estab...

Page 17: ...the high level to inform the host that the data is being processed and outputs the RXD signal to inform the MPU of data reception The data is read upon receiving the RD N signal from the MPU When the...

Page 18: ...Rev 1 1 for normal operation Note Cable is not supplied 3 Table of USB I F signals Contact Signal Name Typical Wiring Number Assignment 1 Vbus Red 2 D White 3 D Green 4 GND Black Shell Shield Drain W...

Page 19: ...Input Output Level Parameter Input Levels High driven High floating Low Output Levels Low High driven Output Signal Crossover Voltage Symbol VIH VIHZ VIL OL OH VCRS Min 2 0 2 7 0 0 2 8 1 3 Max 3 6 0...

Page 20: ...ansmitted 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 Da...

Page 21: ...See 2 1 8 Alarm Circuit c Pin stroke compensation 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 H...

Page 22: ...ent from the MPU Transmission of SP LF Motor Control Data MPU A B A B B A LF A1 A2 B1 B2 M SLATCH N SDATA N SCLK N LSI MHM2025 SPU SPV SPW SPU Distri butor Driver SPV SPW Decoder Space speed register...

Page 23: ...ng through the LSI the pulse length of the output A B of the slit encoder included in the space motor By comparing the target speed for each print mode with the actual current speed to change the spee...

Page 24: ...nd carriage position detection timing UTILITY MODE 1 720 1 120 SPU SPV SPW PHASE A PHASE B IPT 10 CPI 12 CPI 15 CPI IPT 17 CPI 20 CPI 1 240 3 LF Motor Control The LF motor driver MHM2025 drives the LF...

Page 25: ...ch controller 5V 46 A 2 byte 15 bits 1 even parity bit command OPTXD is transmitted to the Operation panel contol IC in synchronization with the OPCLK signal The Operation panel control IC decodes thi...

Page 26: ...can be returned before decoding the command 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...

Page 27: ...ge alarm circuit turn on the ALM N signal is transmitted to the thyristor then the AC fuse transformer assy opens 2 Alarm processing when DC power is low 50V is converted into the POWLEV signal 0V to...

Page 28: ...n the temperature is between122 C and 132 C the mode switches sequentially to higher level When the temperature falls below 118 C the mode switches to lower level When the temperature exceeds 132 C pr...

Page 29: ...f 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: ...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 signal Use 3...

Page 31: ...ves in parallel with the platen Electrically this unit is connected to the control circuits through the control board Figure 2 2 Arrangement of the head pins View from the tip of the printhead 1 The p...

Page 32: ...iven in the direction of the platen by the force of the armature spring The print wire fixed to the armature protrudes from the tip of the wire guide strikes the paper through the ribbon and prints a...

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...

Page 34: ...e shaft in parallel with the platen When the spacing motor rotates counterclockwise the driving force is transmitted to the motor gear As the motor gear rotates the carriage moves from left to right M...

Page 35: ...hed down the adjusting screw can be turned with a screw driver to change the coarse gap adjustment When the adjusting lever is set to range the contact which is attached to the under side of the carri...

Page 36: ...s 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 fro...

Page 37: ...ith a single direction feed is used Ink is supplied from an ink tank which is built in to the ribbon cartridge 2 Ribbon feed operation When the space motor is activated the ribbon gear rotates The rot...

Page 38: ...42114101 Rev 1 38 Drive gear Ink tank Ribbon cartridge Figure 2 6...

Page 39: ...ing 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 ge...

Page 40: ...Continuous sheet from push tractor When the change lever is set to REAR position the change gear is engaged with the idle gear and the tractor gear to transmit the rotation of the platen to the push t...

Page 41: ...se 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...

Page 42: ...e and the rotation of the motor is transmitted through decelerating gears LF idle gear platen gear to the platen When using cut sheet paper the change lever must be in the TOP position to grab the pap...

Page 43: ...r 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: ...heets are fed by these two tractors at the same time To remove slack from the sheets set the sheets according to the following procedure when using the push and pull tractors 1 Set the change lever to...

Page 45: ...1 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 plat...

Page 46: ...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 thro...

Page 47: ...se 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 r...

Page 48: ...42114101 Rev 1 48 Change arm Change lever Platen Release cam Figure 2 13 REAR TOP BOTTOM...

Page 49: ...and the paper near end lever A rotates clockwise CW At this time the rear sensor lever rotates counterclockwise CCW and pulls out of the rear and top paper end sensor to detect that the sheet is prov...

Page 50: ...off position to start printing at the front end of the sheet without causing the sheet to crumple or curl up The printing starts at the front end of the sheet and continues uni directionally until th...

Page 51: ...et of paper between the platen and the paper shoot 3 After the lapse of time selected by the wait time in the menu the LF motor starts its operation to feed the sheet of paper up to the print position...

Page 52: ...start position 5 The paper is fed in up to the TOF position Factory default 0 85 inches from the top Push down the FF LOAD switch Detection of the sheet supplied PE LF action Line feed about 3 inches...

Page 53: ...urs or 19 inches maximum have been fed 3 The paper is fed in reverse to leave the paper on the push tractor Alarm LED lights up when P E is not detected after 19 inches reverse feeding Operator can pr...

Page 54: ...connect the AC cable again connect it to the inlet on the printer first then insert the AC input plug into a receptacle 2 Do not disassemble the printer as long as it is operating normally 3 Do not r...

Page 55: ...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 hook 1 5 J YX4025 83335 3 1 Head gap adjustment 6 Volt...

Page 56: ...rol 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 followin...

Page 57: ...sheet guide 3 3 5 Gear case assy 3 3 6 PC connector 3 3 7 Space motor and guide roller assy 3 3 8 Space rack 3 3 9 Carriage cable 3 3 10 Back up roller holder assy 3 3 11 Platen assy 3 3 19 Paper pan...

Page 58: ...se order Notes on installation 1 Insert the printhead 2 into the PC connector 3 while pushing it against the carriage frame 4 2 The head clamp 1 must surely be sandwiched between printhead 2 and carri...

Page 59: ...01 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 ord...

Page 60: ...eet 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 front rem...

Page 61: ...3 4 Raise the front side of upper cover Assy 3 and shift toward the rear to disengage claws 6 places 5 places for narrow type of frame 5 Raise the upper cover Assy 3 to remove 6 Open the access cover...

Page 62: ...at blade screwdriver push to widen the claw for easy disengagement 6 Remove the gear case Assy 3 in upper direction and release the carriage cable from the cable clamp of the gear case Assy 7 To insta...

Page 63: ...o install follow the removal steps in the reverse order Note on installation 1 Do not touch the space motor 2 or terminals of PC connector 1 Also take care to avoid dust or foreign matters 2 After ins...

Page 64: ...space motor 1 6 To install follow the removal steps in the reverse order Notes on installation 1 Do not touch the terminals of space motor 1 Also take care to avoid dust or foreign matters 2 When inst...

Page 65: ...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 and remove the space rack 2 in upper direction 7 To install follow the remov...

Page 66: ...Remove carriage cable 7 from fasteners on frame 8 To install follow the removal steps in the reverse order Note on installation 1 Take care not to fold the carriage cable 7 during installation Curve s...

Page 67: ...Remove the space motor see 3 3 7 5 Remove the backup roller spring 2 Disengage claws 2 places of roller holder from the carriage frame 1 and remove the backup roller holder assy 3 6 To install follow...

Page 68: ...ll 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 2 on both sides to unlock from the frame then rotate them...

Page 69: ...2 and PCB sheet 5 by lifting clamp 4 3 Disconnect all cables from Control Board 2 4 To install follow the removal steps in the reverse order Note on installation 1 Insert one sensor lever 3 between se...

Page 70: ...er 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 see 3 3 12 7 Remove the left FG plate 1 8 Release the lock A to remove the LF mot...

Page 71: ...Disengage claws on both sides from the frame and remove the operation panel 4 4 Open claws 4 places and remove the operation panel Board 5 from the operation panel 4 5 To install follow the removal s...

Page 72: ...ower Supply Board 1 4 Remove two screws 6 and remove the Power Supply Board 1 5 To install follow the removal steps in the reverse order Remark on assembly 1 To mount the Power Supply Board set the ch...

Page 73: ...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 screws...

Page 74: ...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 the change lever 3 4 To perform mounting follow the reverse proc...

Page 75: ...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 To perform mounting follow the reverse procedure...

Page 76: ...e 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 up the paper chute...

Page 77: ...Remove the reset spring see 3 3 17 3 6 Remove the tractor gear 1 7 Shift the drive shaft 2 to the right side to remove in the direction of the arrow 8 To perform mounting follow the reverse procedure...

Page 78: ...7 To install follow the removal step in the reverse order Note 1 At mounting release shaft 2 pay attention to the gear engagement of release shaft 2 change arm lever 6 change gear shaft 7 2 There are...

Page 79: ...3 17 4 Remove the paper pan see 3 3 19 5 Remove the rear pressure assy see 3 3 21 6 Pull the Switch Lever toward you and remove it upward 7 To install follow the removal step in the reverse order Rema...

Page 80: ...o 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...

Page 81: ...nt method 1 Gap between the platen and the print head at the left end and the right end shall be adjusted by rota ting the adjust cam 2 Set the adjust lever at the Range 1 Press the adjust gear downwa...

Page 82: ...shall be measured positioning the platen gear R craw on the top Note 3 Move the adjust screw in clockwise direction in direction B to measure Measure variation of gap when range is changed 4 1 2 G a...

Page 83: ...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 the motor PCB and it be...

Page 84: ...lever is set at Friction position all the pressure rollers shall be pressed to the platen 2 When the change lever is set at Rear or Bottom position the gap between the pla ten and the pres sure roller...

Page 85: ...tor 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 backlash between gears to allow s...

Page 86: ...ibbon 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 250g or...

Page 87: ...en gear L and the bias gear rotate against each other to pinch the teeth of idle gear The idle gear stays in mesh with the platen gear L and the bias gear and not locked The bias gear and the platen g...

Page 88: ...ng oil to that portion after cleaning 1 Cleaning time When the equipment operating time has reached six months or 300 hours whichever comes first 2 Cleaning tools Dry cloth soft cloth such as gauze va...

Page 89: ...ve the dust on the Sensor 2 Lubricant Pan motor oil or equivalent PM Molicort or equivalent EM 30L 3 Amount of lubricant Medium amount A Apply three to four drops of oil or 0 008 inch 0 2 mm thick gre...

Page 90: ...ar 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...

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: ...M 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 spring Change leve...

Page 93: ...ft plane portion EM 30L A Rear roller holder Shaft Bearing portion of front roller holder and pressure roller EM 30L B Sliding portion of release shaft and rear roller holder EM 30L A Contact portion...

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: ...ing Flowchart No Surmise of Trouble Power is not supplied No spacing operation 1 2 Power Supply Board Control Board Transformer Assy Space Motor Carriage Cable Printhead Homing does not end normally 3...

Page 98: ...t or bottom paper end Set New paper Paper change lever alarm ON OFF BLINK 1 OFF Change lever is set to TOP position while paper is already inserted from rear or bottom Set the lever to specified posit...

Page 99: ...k sum error No reaction when MPU reads data MPU is locked up and it ios reset after 65ms NMI port of MPU is kept low level FFFF data is detected due to MPU locked up Read write error Check sum error R...

Page 100: ...ce motor Replace P H cable Replace Control Board Check the mechanisms if load is too much Check the P H connection Replace Print Head Replace P H cable Replace Control Power Supply Board Print head do...

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: ...HD7 HD13 HD15 50V 50V HD23 HD24 50V 50V HD16 HD14 HD8 HD6 0V N C N C N C N C 1 2 1 2 1 1 2 3 1 2 5 1 2 7 1 2 9 1 2 11 1 3 5 7 9 11 1 2 13 13 1 2 15 15 1 2 17 17 1 2 19 19 1 2 21 21 1 2 23 23 1 2 2 2...

Page 103: ...f each coil should be about 10 4 Signal Connector pin number LF1 LF2 LF3 LF4 CN2 SP Motor A Photo sensor Thermistor 5K at 25 C B 3 5 2 20 19 17 18 22 3 Space Motor Resistance of each coil should be ab...

Page 104: ...er Supply Board blown No Yes Replace fuse with same type and rating Remedied No Yes End Does DC 50V out No Yes Remove Print Head Turn power off then on Remedied No Yes End Replace carriage cable or ri...

Page 105: ...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...

Page 106: ...age 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 Ye...

Page 107: ...m 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 No Yes End Replace...

Page 108: ...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 of change gear shaft change...

Page 109: ...g 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 car...

Page 110: ...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 Rep...

Page 111: ...tridge 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...

Page 112: ...en assembly Is the LF motor idle gear broken No Yes Replace the LF motor assembly or LF idle gear Is the platen gear R idle gear or change gear broken No Yes Replace the gear Set change lever to the r...

Page 113: ...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 Re...

Page 114: ...press Ineffective when the function is not required Is the I F RS232C No Yes To step 10 2 Does the SEL LED light up Yes No Press SEL key Remedied No Yes Does the printer receive data properly No Yes T...

Page 115: ...oting Make sure of the parameters for RS232C in the menu are correct Baud rate Bit length Parity Protocol Busy signal and its polarity Remedied No Yes End Is 12V 8V supplied on Control Board Yes No Re...

Page 116: ...ev 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 B...

Page 117: ...art 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 are used to...

Page 118: ...01 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 N 1 2 For ML490 4...

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: ...TFS 1 9 4 55081109 Operator panel board 1 3 LEOP 5 42116101 Operation panel 1 2 6 AC cord for 120V 1 1 AC cord for 230V 1 1 AC cord for 230V 1 1 7 42124201 Print head 24 1 10 8 42124701 Fuse Trans 125...

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: ...2 For ML490 42256201 Leaf spring W 1 2 For ML491 9 50809301 Paper end lever 1 1 10 40775901 Sensor lever 1 1 11 51228001 Change gear 1 2 12 51228101 Tractor gear 1 2 13 50931401 Pressure spring R 3 2...

Page 123: ...e Weld 1 1 30 42044701 Pull up roller assy N 1 2 For ML490 42045701 Pull up roller assy W 1 2 For ML491 31 40355101 Idle gear 9 1 4 32 53350302 Tractor frame assy R 1 2 33 53350202 Tractor frame assy...

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: ...oller holder assy 1 2 5 6 42104201 Space motor assy 24 1 4 7 1 42252704 Head cable 23 1 5 ML490 42252702 ML491 7 2 42252801 Head cable 20 1 5 ML490 42252802 ML491 8 PC connector 36 40 1 2 9 51238801 G...

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: ...actor 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 51902301 Bottom push stand L 1 2 5 51902302 Botto...

Page 128: ...bits per second Two protocols are available printer Ready Busy and X ON X OFF modes 2 OPERATION DESCRIPTION 2 1 Element Description 1 80C51 with MASK ROM An eight bit microprocessor controller that c...

Page 129: ...Operation at power on After power is turned on an RST OUT signal is sent from the printer control board to reset the printer When the reset is canceled the 80C51 CPU performs initialization Initializa...

Page 130: ...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 Yes No Yes Is remaining buffer space 256 Yes No Turn on the SSD signal Turn off the...

Page 131: ...ter in DESELECT state or is the paper low No No Yes Yes No DSR High Yes Store 40 H in buffer Yes Yes No Yes Is remaining buffer space 256 Yes No Printer busy No Output one character to printer No Yes...

Page 132: ...rinters self test and thoroughly test the printers functionality If the trouble is reproducible proceed to the troubleshooting section 3 2 Troubleshooting 1 The data is not received using a serial int...

Page 133: ...ST bit SP bit 5V 0V 5V 0V RxD SSD No Replace the Q3 Yes Are T1 SELECT and INTO BUSY signals low level No Check Q3 on the Control Board Yes Are 9V and 9V input to Q1 No Replace defective component in...

Page 134: ...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 BUS signals at Q7 pins 2 9 the same as that of DB0 7 when WR signal is star...

Page 135: ...The program revision using two numerical characters is printed 2 LOOP TEST is printed 3 Memory is checked for the message buffer 4 Prints OK is printed if the memory check is OK and BAD is printed if...

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Oki ML490 Series, Maintenance Manual

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Summary of Contents for ML490 Series

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