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1. 3 When installing the space motor 1 align the face C with carriage frame 4 and push portion D against the frame 4 After installation check and adjust the gap between platen and printhead see 4 1 7 Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com CUN M N 1 NC ON AAA NEN d V NEN CUR 8 X 3 9 di CAR Page 7 6000 AT A Service Guide ML390 ML391 Turbo Chapter 3 Assembly Disassembly 3 3 08 Space Rack 1 Remove the printhead see 3 3 1 lt 3 2 Remove the upper cover see 3 3 4 i 3 Remove the shim from the carriage frame 4 Remove the gear case Assy see 3 3 5 44 5 Remove the space motor see 3 3 7 i 6 Remove the spring 1 7 Disengage the claw on left side of space rack 2 from the frame and remove the space rack 2 in upper direction 8 To install follow the removal steps in the reverse order Note on installation 1 After installation check and adjust the gap between platen and printhead see 4 1 44 Partner Exchange BPX for any updates to this material http bpx okidata com Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Page 8 6000 AT A Service Guide ML390 ML391 Turbo PR Chapter 3 Assembly Disassembly 3 3 09 Carriage Cable 1 Remove the
2. 2 1 08 Alarm Circuit 2 1 09 Power Supply Circuit 2 2 01 Printhead Mechanism and Operation 2 2 02 Spacing Operation 2 2 03 Head Gap Adjusting 2 2 04 Ribbon Drive 2 2 05 Paper Feed Operation E 1 Cut Sheet and Continuous Forms Switching Mechanism 2 Cut sheet feeder operation ES 3 Continuous Forms Operation Rear Push and pull tractor mechanism Option cae 5 Pull tractor mechanism option 6 Bottom Push Feed Operation Option x 7 Paper Clamp Mechanism 2 2 06 Paper Detection Mechanism 2 2 07 Automatic Sheet Feed 2 2 08 Paper Park Function Continuous Forms 3 Assembly Disassembly ASSEMBLY DISASSEMBLY 3 1 Precaution for Parts Replacement 9 2 Service Tools Table of Contents 3 3 Disassembly Reassembly Procedure How to Change Parts TN 3 3 01 Printhead eens 3 3 02 Ribbon Protector 8 3 3 03 Pull up Roller Assy 3 3 04 Upper Cover Assy Access Cover Assy and Sheet Guide Assy DD 3 3 05 Gear Case Assy 3 3 06 PC Connector 3 3 07 Space Motor Guide Roller Assy 3 3 08 Space Rack pies 3 3 09 Carriage Cable 3 3 10 Backup Roller Holder Assy 3 3 11 Platen Assy eee 3 3 12 Driver Board SRXD T 3 3 13 LF Motor 3 3 14 Operation Panel PCB LEOP Aud 3 3 15 Control Power Supply Board SRXC eae 3 3 16 Transformer Assy 3 3 17 Change Lever and Gears 3 3 18 Carriage Shaft 3 3 19 Paper Pan T NUN 3 3 20 Rear Tractor Assy 5 3 3 21
3. 8 Line feed trouble 9 Malfunction of switch on operation panel eins 10 Data receiving failure A PCB Layout APPENDIX A PCB LAYOUT B Parts Listing SPARE PARTS LIST Upper Cover Assembly Figure 11 1 Printer General Assembly Figure 11 2 Printer Unit Figure 11 3 1 of 2 Printer Unit Figure 11 3 2 of 2 Carriage Option Assembly Figure 11 4 Option Spare Parts Figure 11 5 C RS 232C Serial Interface Board APPENDIX C RS 232C SERIAL INTERFACE BOARD C2 Operation Description C2 2 01 Operation at Power On E C2 2 02 RS 232C Interface 62 3 Communication Procedure Flowchart 56 C2 3 02 Mode B Figure C 2 3 C3 Troubleshooting Flowcharts Table of Contents Page Local Test 118 3 3 C3 3 1 2 Function 119 Page 2 OKID AT A Service Guide ML390 ML391 Turbo e es Chapter 0 About This Manual Disclaimer This document may not be reproduced without the written permission of Okidata Training and Publications Every effort has been made to ensure the accuracy of the information contained in this training course Okidata is not responsible for errors beyond its control Copyright About Information 1996 by Okidata All rights reserved First Release P N 59274601 November 1996 Written by OKI Data Corporation 11 22 Shibaura 4 chome Minato ku Tokyo 108 Japan Tel 81 Japan 3 Tokyo 5445 6159 Fax 81 3 5445 6188 Revised by Okidata Training and Pub
4. Thank You for purchasing this Factory Service Manual on EBAY from PCTECHI NFO Click Here for more Factory Service Manuals for other Computer and Printer Copier Manufacturers from PCTECHI NFO Page 1 OKIDATA Service Guide ML390 ML391Turbo md Chapter 0 About This Manual OKIDATA Service Manual ML390 Turbo ML391 Turbo Dot Matrix Printers Adobe Acrobat printable reference copy of the OKIDATA Service Training Manual 09 17 97 Note This Adobe Acrobat version of the Okidata Service Training Manual was built with the pictures rendered at 300 dpi which is ideal for printing but does not view on most displays well Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page Table of Contents Service Guide ML390 ML391Turbo 0 About This Manual Front Cover Copyright About Information 1 Configuration 1 1 Standard Printer Configuration 1 2 Options 2 Theory of Operation 2 1 01 Summary 2 1 02 Microprocessor and the Peripheral Circuit R Printer Block Diagram Figure 2 1 50 Program ROM UE RAM MSM51C464A 80RS C Large Scale Integrated Chip LSI 2 1 09 Initialization 2 1 04 Parallel Interface Control 2 1 05 Print Control Print Compensation Control 2 1 06 Space Motor Line Feed Motor Control 2 1 07 Operation Panel
5. 1 Ribbon feed gear Assy Paretan gear shat Drive gear shaft upper and lower upper anc wer PIMEB 0 00640 Ocergi El 3OL A lde gear shaft upper and Ewen PREB ioo oos Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http opx okidata com Page 9 r c Service Guide ML390 ML391Turbo OKIDATA Chapter 5 Cleaning and Lubrication 2 Space rack Space rack 5 gesing range Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 80 OKID AT A Service Guide ML390 ML391 Turbo Chapter 5 Cleaning and Lubrication 3 Platen Assy l Contact face of platen shaft Bias gear and platen FG spring U EM 30L B i Grease the contact face of platen gear iL and bias gear Phu B w Platen gear IL Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 81 6000 AT A Service Guide ML390 ML391 Turbo 2 Chapter 5 Cleaning and Lubrication 4 Tractor driving mechanism Change lever sliding surface of change arm and change lever EM 30L A Tractor gear bearing portion Change arm
6. AE m ET 2 2 2 2 Er 2 Thermistor Typ k oim Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 91 OKID AT A Service Guide ML390 ML391 Turbo Chapter 6 Troubleshooting and Repair 2 Line Feed Motor Resistance of each coil should be about 7 6 Ohms oignal Connector pin number OME LF1 LF2 LF3 LF4 Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 2 p 0 Service Guide ML390 ML391Turbo OKIDATA Chapter 6 Troubleshooting and Repair 3 Space Motor Resistance of each coil should be about 5 Ohms oignal Connector pin number P L 3F wVv 3F N SPA SPB EL Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 3 OKID AT A Service Guide ML390 ML391 Turbo 0 P Chapter 6 Troubleshooting and Repair 6 5 Troubleshooting Flow Charts amp ls the AG cable connected comecth Yes Mo Connect the AG cable comecthy _ fuse F1 on the transiormmer assyfor F1 on the cantmlpoauwer supply board blown Mo Yes a Repl e
7. After adjustment mark the adjust cam position with a red pen After adjustment mark the adjust composition with a red pen M Left Right MC OS Adjust cam Marking Carriage shaft Paten a E Adjust lever d Adjust ar Pl 7 Adjust screw Adjust cam Adjust lever Adjust 3 spring a Adjust Click of platen gear H Print head W x Adjust lever Adjust gear ba i Ly Platen Adjust cam Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 64 6000 AT A Service Guide ML390 ML391 Turbo Chapter 4 Adjustments 4 1 2 Measure variation of gap when range is changed No item Specification Drawing Adjustment method 4 1 2 Measure variation of Gap 0 71 gap when range is 0 05 at the range changed 5 Gap between the O3mm or more Confirm followings contact and the monitor Make sure that the gap between the contact and the motor PCB is 0 33 mm or more At the time of printing test make sure that the contact touches the motor PCB and it becomes reduced speed mode when the adjust lever is set to range 2 and 4 Adjust lever Contact Motor POE Touching Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchang
8. Chapter 3 Assembly Disassembly 3 3 03 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 front remove from the shaft of platen Assy 4 4 To install follow the removal steps in the reverse order Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 43 6000 AT A Service Guide ML390 ML391 Turbo j Chapter 3 Assembly Disassembly 3 3 04 Upper Cover Assy Access Cover Assy and Sheet Guide Assy 1 Pull off the platen knob 1 2 Open the access cover Assy 4 toward the front to remove 3 Lift up the sheet guide Assy 5 to remove 4 Turn the change lever 2 toward the bottom position 5 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 6 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 7 Raise the upper cover Assy 3 to remove 8 To install follow the removal steps in the reverse order Remark on assembly Match the posts A at the both sides of the Sheet Guide 5 with the arrow marks on
9. Fie red ied Ma Y ez 4 End Fe place VF cable Printer WF pin assignment TxD e pin RFC 3 pin S50 11 pin CTR 20 pin DSR 5 pin 2 RSE MF the corect cable used Yes Ma Shange IF cable Iz ALARM LED blinking Ma Yes See tables 6 2 and 6 3 tor the troubeshooting hake sue of the parameters for RSE in the menu am conect Driver Board E BH HE HE HH HE HE HH TOM pine Busy signal and its polarity Baud rate Bit length Parity Protec 4 Rereded Ma Yes Eng l 5M suppled on Onwer Baar Yes Ma Remove RSE WF Board the SY supplied on the Driver Baar Ma Y ez Repke RSE IF Board Replace Driver Board a Replace ASSS25 Board x Hemedied Mo Yes End Replace Driver Board Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 3 OKIDATA Service Guide ML390 ML391Turbo BJ Chapter A PCB Layout APPENDIX A PCB LAYOUT PCB List 1 Circuit board SRXC Control Power Supply 2 Circuit board SRXD Driver 3 Circuit board LEOP Operation Panel 1 Control Power Supply Board SRXC SF 1 2 4 Mbit E PE Ghi 1 2 1 alala s 2 3 1 M2 bi EPR ON SP2 i Br and 3P 2 A B 2P3 Al IBI and Ta use program ROM of Cr SPS A B 3P2 in 503 A
10. NS TOP GLO SE GLO SE TOP 1 Change am Figure 2 14 Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 32 FA Service Guide ML390 ML391Turbo OKIDATA Chapter 2 Theory of Operation 2 2 06 Paper Detection Mechanism Refer to Figure 2 15 The three paper detection types are listed below 1 Cut Sheet Detection 2 Rear Feed Detection 3 Bottom Feed Detection 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 The procedure for the paper end is made in the reverse order that is its detection is performed when the paper end sensor is blocked Rear Feed Detection When the paper is fed from the push tractor the point B is pushed to the front side 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 paper is provided The procedure for the paper end is made in the reverse order that is its detection is performed when the rear sensor lever intercepts the sensor
11. 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 8 A Service Guide ML390 ML391Turbo OKIDATA Chapter 2 Theory of Operation 2 1 08 Alarm Circuit 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 alarm circuit sends an ALARM N signal to turn on the SCR SO This cause the secondary coil 40V of the transformer to be short circuited causing an overcurrent to flow through the primary coil and making the AC fuse transformer ASS open Alarm Processing When DC Power is Low 40V is converted into the POWLEV signal OV to 5V by R531 and R532 and input into the A D port of the MPU to control the drive time and the print speed pass number of the head Tory Fra 1 Praw LEW FESS Head Drive Time The head drive time is lengthened to compensate for the amount of voltage drop by monitoring the POWLEV signal once every 500 m sec to control and maintain the impact necessary for each printing pin at the fixed value Print Speed BM or more 100 25y 37V 00 30 25V ar ess SO Head Overheat Alarm The voltage of the output TSD signal of the thermistors one of which is contained in the print head and the other
12. 3 3 20 Rear Tractor Assy 1 Remove the printhead see 3 3 1 5 2 Remove the ribbon protector see 3 3 2 i 3 Remove the pull up roller assy see 3 3 3 i 4 Remove the upper cover see 3 3 4 43 5 Remove the reset spring see 3 3 17 i 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 of removal Remark on assembly 1 When the Tractor Assy L 3 R 4 have been detached from the Drive Shaft align the protrusions 5 of the Pin Tractor Wheels to the same direction before assembly Partner Exchange BPX for any updates to this material http bpx okidata com Inc All rights reserved See the OKIDATA Business Copyright 1997 Okidata Division of OKI America Page 60 OKID T x Service Guide ML390 ML391Turbo A A Chapter 3 Assembly Disassembly 3 3 21 Rear Pressure Assy 1 Remove the upper cover see 3 3 4 43 2 Remove the change lever and gears see 3 3 17 44 3 Remove the paper pan see 3 3 19 i 4 Remove the rear pressure roller 1 5 Rotate the release shaft 2 and move it to the left to detach the release shaft 2 Match the Main Frame Rib A with the protrusion B of the Release Shaft 6 Remove rear pressure SP assy 3 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 r
13. Ass 56513602 pressure N presser meum ee p pressure W Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com 1 Page 108 OKID AT A Service Guide ML390 ML391Turbo Chapter B Parts Listing Printer Unit Figure 11 3 2 of 2 Remaks ODA p GEMMESEN 3PA4044 5025G2 n T Foris Tuis For ML390 Turbo ot 14801 Platen N mE 3PA4044 5159G2 Assembly For ML391 Turbo 50114901 Platen W 24 3PP4044 5010P1 Rack Space N yt E or ML390 Turbo 53349601 EN 5156P1 iom Space TI ML391 Turbo 53349701 4PB4025 3377P2 Song Tension P 50923502 SpaceRack x rs 5008P1 Plate n AE For ML390 Turbo 51022201 Rail N Lom 5155P1 um TT ML391 Turbo 51022301 Rail W 27 3PP4025 2810P2 ies cm Yo l 51238601 m 5009P1 E Carriage NN For ML390 Turbo 51114201 BH bd 5009P2 Sam Carriage LI ML391 Turbo 51114202 29 3PP4044 5005P1 P FG L 51022401 Assy N eret rwr pee m Assy W Motor 24 Lower Assy R 39 4PA4044 5043G2 Frame Tractor 53350202 Assy L P TiPP4025 3395P4 enaft Drive For MESST Turbo 51114404 35 3PP4044 5046P 1 Guide Tractor 1 x ML391 Turbo 3 022901 Sheet 4PB4044 5095P1 Plate FG A 1622701 ee 3PP4044 5089P1 Shaft Change a 3 51114301 Gear Copyright 199
14. Bottom Feed Detection When the paper is fed from the bottom the point C rotates clockwise CW When the bottom sensor lever rotates clockwise CW it pulls out of the bottom paper end sensor to detect that the paper is provided The procedure for the paper end is made in the reverse order that is its detection is performed when the bottom sensor lever intercepts the sensor Paper End Sereor Bottom Paper End Lever Figure 2 15 Top Line Print Mechanism Refer to Figure 2 16 below The top edge of the sheet is protected by the ribbon protector so that it can stop at a position near to the print head 0 tear off position to start printing at the top 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 the front end of the sheet gets to the inside of the pull up roller cover After that that printing continues bi directionally EN Printhead Cariag fame zem m bly Figure 2 16 Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http opx okidata com Page 33 OKID AT A Service Guide ML390 ML391 Turbo P Chapter 2 Theory of Operation 2 2 07 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 forms is u
15. ET Ide gear teeth udin Nie Heset spring ks Gear 1 bearing portion 2 Sliding surface of change El 3 0L sliding surface Of Jever and gear reset spring and gear Elut 30L EM 30L A Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 2 6000 AT A Service Guide ML390 ML391 Turbo P Chapter 5 Cleaning and Lubrication 5 Tractor drive shaft sliding surface of Fi spring and drive shaft end Elv 30L Nc T Drive shaft bearing portion CNN d EM 30L A A Arrow view Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 83 6000 AT A Service Guide ML390 ML391 Turbo lx Chapter 5 Cleaning and Lubrication 6 Pressure roller Change arm sliding portion of release ES P4 shaft and change arm M EM 80L A Leo Release shaft suppert spring nais Contact portion of support 5 spring and shaft END An Front pressure roller EM 30L s lies a E a e Contact portion of rear 92 i holder and shaft aaa EM 30L A T Controller holder olding portion of rear roller holder and sliding portion of E E release shaft cam surface release release shaft and rear 7 I m shaft plane portion
16. Lubrication 9 Carriage Assy NE2 10 SLIS Bearing portion of guide roller El 30L B Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 87 OKID AT A Service Guide ML390 ML391 Turbo re Chapter 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 the trouble occurred 4 Proceed with the repair as follows Check the trouble status according to Table 6 1 7 for the details of the trouble Then locate the trouble position according to the detailed flowchart 5 Carry out a thorough test after the repair to check for correct functioning Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http opx okidata com Page 8 6000 AT A Service Guide ML390 ML391Turbo B Chapter 6 Troubleshooting and Repair 6 2 Troubleshooting Table Trouble Troubleshooting Surmise of Trouble No Trouble upon power on Power is not supplied Control Power Supply Board Driver Board Transformer Assy Space Motor Carriage Cable P
17. buffer memory and interface driver receiver circuit It then prints characters To start and stop this test push the SEL switch on the front of the printer To cancel the test hold the SEL and SHIFT switches and turn the printer on Move to the menu option for the test and change Diagnostic Test to No Here is an explanation of the details of this test 1 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 the memory check fails 5 Output level to DTR RTS and SSD signals is dropped low If DSR CTS or CD signals is High IF BAD is printed If DSR CTS and CD signals are all Low IF OK is printed 6 Output level to DTR RTS and SSD signals is raised high If DSR CTS or CD signals is Low IF BAD is printed If DSR CTS and CD signals are all High IF OK is printed 7 Transmits characters codes from 20H to 7FH is transmitted by SD signal At the same time characters are received by the RD signal and stored in the message buffer 8 The characters that were stored in the message buffer as indicated in 7 are printed 9 Steps 1 through 8 are repeated until test is interrupted Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this mat
18. cover see 3 3 4 i 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 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 installation check and adjust the gap between platen and printhead see 4 1 7 http opx okidata com Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material Page 46 6000 AT A Service Guide ML390 ML391 Turbo Pe Chapter 3 Assembly Disassembly 3 3 07 Space Motor Guide Roller Assy 1 Remove the printhead see 3 3 1 lt 3 2 Remove the upper cover see 3 3 4 43 3 Remove the gear case Assy see 3 3 5 4 Remove the PC connector see 3 3 6 i 5 Remove screw 2 then the guide roller Assy 3 from the space motor 1 6 Push down on the carriage cable and remove it 7 Remove the screws 5 then remove the guide roller assembly 3 from the space motor assembly 8 Remove the space motor 9 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 installing the guide roller Assy 3 push portions A and B against the space motor 1
19. fuse with same type and rating a Reredied Mo Yes End Does DX M out Mo Yes a Remove Print Head Turn power off then an Hemedied Mo Yes End a Heplaece camage cable or nbbon Ged mechanism a Hemedied Mo Yes End Repl e Gantral Pewer Supply Board Remove SHS on Driver Board amp liezsurm for any short cimu between 5M 40V Sy OW EL or EP Any short cimumit Ma Y ez Mo Yes Driver Board Drwer Baar Replace Trareformer Assy 0 Hemedied Mo Yes 5 OBH End Replace Gontml Power Supply Board Pin Mo 20 fia ie i ie fis 14 12 fio fa Je v e 5 A EL T 40 Tow Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 4 OKID AT A Service Guide ML390 ML391 Turbo J Chapter 6 Troubleshooting and Repair 2 No Spacing Operation The Alarm LED Blinks 2 Mao Spacing operation J The alam LED Blinks x ls carnage assembl binding or jammed Mo Yes a Check around space motor to repair tha mechanism of space rack back up mler ribbon feed mechanism and carnage frame etc Replace space motor assy Henmedied Mo Yes a End Heplace Driver Board Henmedied Ma Y ez End Fie place carriage cable Copyright 1997 Okidata Division of OKI Ameri
20. in the print head driver is monitored by the CPU AD port to control the voltage Temp Stop 19 C Made up Made down iade and Pont Gontrol ie Speed Pass Direction Bi Bi e When the temperature is between aC and 119 C the mode switches sequentially to higher level When the temperature falls below B C the mode switches to lower level e When the temperature exceeds 119 C printing will stop e When temperature gradient is steep higher mode shall be specified directly Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 9 c Service Guide ML390 ML391Turbo OKIDATA Chapter 2 Theory of Operation 2 1 09 Power Supply Circuit This power supply circuit supplies the 5VDC 8VDC 40VDC 10VAC T5 AC 10 Logic IC LED drive voltage Serial interface line voltage and SP motor driver Printhead LF motor drive voltage SP motor drive voltage Option board Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 20 Service Guide ML390 ML391Turbo 5 OKIDATA Chapter 2 Theory of Operation 2 2 01 Printhead Mechanism and Operation Refer to Figure 2 2 shown below The printhead is a spring charged 24 pin driving h
21. install follow the removal steps in the reverse order Notes on Installation Important Before inserting the printhead note that there is a shim on the carriage frame 4 which hangs over the platen side of the frame Be sure to replace the shim correctly Improper positioning of this shim will severely affect the printhead gap and therefore affect print quality 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 carriage frame 4 as shown fig 3 3 2 3 Be sure to check the gap between platen and printhead see 4 4 Be careful not to touch the print head while it is very hot Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 41 6000 AT A Service Guide ML390 ML391Turbo ini ta Chapter 3 Assembly Disassembly 3 3 02 Ribbon Protector 1 Remove the printhead see 3 3 1 lt 3 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 Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 2 6000 AT A Service Guide ML390 ML391 Turbo B
22. ropes netu re Main i os Bi the meal alam excede 11577 Bo rd t iz recovered Spa medor Temperature of Space rator o FATALALARM L Fite Note BLINK1 400ms ON 400ms OFF BLINK 2 200ms ON 200ms OFF LED is kept in Current Condition no chang 2 Fault alarm display When the printer detects any of the various alarm states the information is displayed as shown below on the operation pan PRINT La CL IEAIEF Er z s E mE E Er m z mE CHARACTER PITCH EXIT GROUP FRINT zm POWER ALARM MERI Figure 64 Table amp 3 174 ALAF LED DISPLAY ALAFih REMARKS HES CATEGORY Es um e m a moe un mg MPU intemal Readwite error Regae Contra FA alam Power Supay Board Program Fico Check sum error ene rom or Con alam Spo Beard CONTROL RAM on control Fieaciwiite error Fete ALAF Eza dala m Power Supply Beard aee s I s gt fo enm aera Horacio when MPO Replace Contra EEPROM amm CERAM MPUis lockedupandit Tum he power FF and WOT wath Dog gy FIRM ARE HHI portar MPLS Tum he power GFF and DETECTION MMI signal ala mn iepticu leval OM ar 0 Control ALAF hM Power Sugis Boa rd BRK ine tructon FFFF data iz detected Replace Fite Or Con alami due MPU locked up Power Supply Board MP intemal Fieachwrite error circ LF Bear FAH alam
23. the upper cover Push the Guide into the Cover Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 44 OKID AT A Service Guide ML390 ML391 Turbo B Chapter 3 Assembly Disassembly 3 3 05 Gear Case Assy 1 Remove the printhead see 3 3 1 3 2 Remove the upper cover see 3 3 4 43 3 Move the carriage Assy to right hand side remove two screws 1 and then remove the space motor 2 4 Disconnect a carriage cable 5 Disengage claws 4 places Using a flat 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 7 To install follow the removal steps in the reverse order Note on installation 1 To assemble align the direction of the SP motor axis 4 with the Gear Hole of the Gear Case assy 2 Be sure to check and adjust if necessary the gap between platen and printhead see 4 1 3 Partner Exchange BPX for any updates to this material http bpx okidata com Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Page 45 OKID AT A Service Guide ML390 ML391 Turbo alla Chapter 3 Assembly Disassembly 3 3 06 PC Connector 1 Remove the printhead see 3 3 1 5 2 Remove the upper
24. 391 Turbo Chapter 3 Assembly Disassembly 3 3 18 Carriage Shaft 1 Remove the printhead see 3 3 1 3 2 Remove the upper cover see 3 3 4 43 3 Remove the driver board see 3 3 12 3 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 of removal Note on installation 1 After installation check and adjust the gap between platen and printhead see 4 1 7 Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 58 OKID AT A Service Guide ML390 ML391 Turbo FP Chapter 3 Assembly Disassembly 3 3 19 Paper Pan 1 Remove the printhead see 3 3 1 3 7 2 Remove the ribbon protector see 3 3 2 3 3 Remove the pull up roller assy see 3 3 3 i 4 Remove the upper cover assy see 3 3 4 i 5 Remove the platen assy see 3 3 11 i 6 Release claws A 7 Lift up the paper chute assy 1 and remove 8 To perform mounting follow the reverse procedure of removal Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 59 OKID AT A Service Guide ML390 ML391 Turbo alla Chapter 3 Assembly Disassembly
25. 7 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 9 6000 AT A Service Guide ML390 ML391Turbo Chapter B Parts Listing Carriage Option Assembly Figure 11 4 No Part No Description Qty 6006 4PP4044 5061G1 Frame Carriage H 53349801 2 o 0 0 4PA4025 3718G1 Assy Backup 53343201 Roller Holder 4 4PP4025 3398P1 Roller Guide 53341901 5 3PP4044 5065P1 Holder Guide Roller E 3 r pm Motor Space Assy 1 56513701 24 7 3PP4044 5015P1 Cable Printhead 1 For ML390 56634001 24N Turbo 3PP4044 5157P1 Cable Printhead 1 For ML391 56634101 24W Turbo 8 3PB4025 1241P1 PCconnector 36 00 56719200 9 3PA4044 5070G1 Gear Case Assy 1 51238801 10 3PP4044 5068P1 Clamp Printhead 1 507090001 11 4PP4044 5067P1 Plate Printhead H 51022501 12 SPP4044 5064P1 Protector Ribbon 1 53077100 4PP4025 3397P2 Spring Backup Roller MEM NE 50925001 Holder 14 4PP4044 5066P 1 Spring Guide Roller 1 50931801 Holder Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BP X for any updates to this material http bpx okidata com Page 110 OKID AT A Service Guide ML390 ML391 Turbo Chapter B Parts Listing Option Spare Pa
26. AT A Service Guide ML390 ML391 Turbo al F Chapter 3 Assembly Disassembly 3 3 14 Operation Panel PCB LEOP 1 Remove the upper cover see 3 3 4 i 2 Disconnect the cable 1 from connector 3 of Driver board 2 3 Disengage claws on both sides from the frame and remove the operation panel 4 4 Open claws 8 places and remove the operation panel PCB 5 from the operation panel 4 5 To install follow the removal steps in the reverse order Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 4 6000 AT A Service Guide ML390 ML391 Turbo j Chapter 3 Assembly Disassembly 3 3 15 Control Power Supply Board SRXC 1 Remove the upper cover see 3 3 4 i 2 Disconnect two flexible cable 3 from the connector 2 the Control Power Supply Board 1 3 Remove the cable 5 from the connector 4 on the Control Power Supply board 1 4 Remove two screws 6 and remove the Control Power Supply Board 1 5 To install follow the removal steps in the reverse order Remark on assembly 1 To mount the Control Power Supply Board set the change lever to the top position so that the Switch Lever 7 will not hooked on the microswitches 8 Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this mate
27. DATA Service Guide ML390 ML391 Turbo Fa Chapter C RS 232C Serial Interface Board C2 3 02 Mode B Figure C 2 3 Femra conie hase Ma Wes DSF valid Yes IS R High Wes Eu fer hia lore the recereed prinierin DES ELEC Yes Shale or thee paper bow E remann buffer spas x Iz ee buffer spect Sob during meme iri ca E Ma Ma Send OG aler sondnqDoz is UE T or frs d mgd gla Feed to sard Send DI 1 mine ha Cuiputore cherecter io printer Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 117 OKID AT A Service Guide ML390 ML391 Turbo QE F Chapter C RS 232C Serial Interface Board C3 Troubleshooting Flowcharts C3 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 same situation as that at the time of trouble occurrence to see if the same trouble occurs again If not perform the printers self test and thoroughly test the printers functionality If the trouble is reproducible proceed to the trouble shooting section C3 2 Troubleshootin
28. Guide ML390 ML391Turbo OKIDATA Chapter 2 Theory of Operation 2 1 06 Space Motor Line Feed Motor Control Space Motor Control The SP motor driver HA13412 drives the three phase brushless motor based on the phase signal SPU SPV and SPW and the speed instruction data from the LSI The MPU can identify the current speed of the space motor by measuring 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 speed instruction data the motor speed is accelerated or decelerated to maintain the specified speed for each print mode A Ld AP SP Truth Table HALL AMP INPUT OUTPUT H H L 1 1 L L L 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 and carriage position detection timing SPL 3F SPN DJ e L 1 3 ne f LI LT un UTILITY WoD E IPT 1a CPI Teu a IPT 120 Fl E IPT 12 CPI T1223 IPT 17 CPI IPT zac Pl Wed Line Feed Motor Control The Line Feed motor driver MTD2005F drives the Line Feed motor in two phase or 1 2 phase bipolar based on the phase changeover data a
29. M IC chips and boards do not use gloves which may cause static electricity 8 Do not place the printed circuit board directly on the equipment or on the floor 9 If adjustment is specified in the middle of installation follow the instructions fa AS input plug Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 37 6000 AT A Service Guide ML390 ML391 Turbo ini ta Chapter 3 Assembly Disassembly 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 Senice took 2 mais Mao 1 100 Fhillips 3 bun mm Ma 2200 Phillips Se Pens screw diver z5 mm Ma 5100 ANE Head gap 5 a L J 5 5 adjustment i i mee jJ Head 1 1 Ibe 505 bar pressure gauge Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 38 OKIDATA Service Guide ML390 ML391 Turbo 0 RJ Chapter 3 Assembly Disassembly 3 3 Disassembly Reassembly Procedure This section explains the assembly replacement procedures according to the following disassembly system Parts Layout Copyrigh
30. Note on installation 1 Insert one sensor lever 3 between sensor when installing the driver board 2 Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 2 ALIR 47 AP Service Guide ML390 ML391Turbo OKIDATA Chapter 3 Assembly Disassembly 3 3 13 LF Motor 1 Remove the printhead see 3 3 1 lt 3 2 Remove the ribbon protector see 3 3 2 3 3 Remove the pull up roller Assy see 3 3 3 3 4 Remove the upper cover see 3 3 4 43 5 Remove the platen Assy see 3 3 11 i 6 Remove the driver board see 3 3 12 i 7 Remove the left FG plate 1 8 Release the lock A to remove the LF motor 2 9 To install follow the removal steps in the reverse order Remark on assembly 1 Press the LF Motor Cable with a portion A of the Motor Plate Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http opx okidata com S E E 3 w 8 e 3 x 3 S n po A x 2 E Bc m ige s 0 A a a N rade d ER t 3 dX oA S XN NEL A Y ue Or o i x p 1 4 k bi 1s 1 9 A amp o AS b URS ge E AM VA uo 8 RA C N Qn Ed E PE i 3 3 a lt bw 2 a 775 FA ri u 1 x F LS A EN s bae 19 M 2 Page 3 OKID
31. Rear Pressure Assy 3 3 22 Switch Lever 4 Adjustments 4 ADJUSTMENT 4 1 1 Gap between the platen and the printhead 4 1 2 Measure variation of gap when range is changed 4 2 Gap between the platen and the paper pan 4 3 Gap between the platen and the pressure roller 4 4 1 Rotation of the push tractor 4 4 2 Backlash between gears 4 5 1 Ribbon feed 4 5 2 Running load to spacing mechanism 4 6 Engagement of the double gear and the LF motor idle gear of the Platen 5 Cleaning and Lubrication 5 1 Cleaning 5 2 Lubrication 1 Cleaning time 2 Lubricant 3 Amount of lubricant 4 Areas to Avoid 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 Table of Contents pe 5 Lubrication points 1 Ribbon feed gear Assy 2 Space rack ieee 3 Platen Assy ieee 4 Tractor driving mechanism m 5 Tractor drive shaft 6 Pressure roller TO 7 Pull up roller Assy 8 Main chassis Assy e 9 Carriage Assy 6 Troubleshooting and Repair 6 1 Items to Check Before Repair 6 2 Troubleshooting Table 6 3 Lamp Display 6 4 Connection Circuit Check for Printhead and SP LF Motor err 2 Line Feed Motor E 3 Space Motor 6 5 Troubleshooting Flow Charts 2 No Spacing Operation The Alarm LED Blinks 3 Homing does not end normally 4 Paper jam while paper insertion TTE 5 Smearing Missing Dots RH 6 Faint or dark print Ribbon feed trouble
32. aled under the wire guide A thermistor in the printhead prevents burning caused by over heating of the coil during extended continuous bi directional printing When the temperature of the coil exceeds a pre determined limit about 119 C the control circuit detects a thermistor signal Printing will then be intermittent or stop completely until the coil temperature falls below the limit value n WW hen printing Am ature assem biy I Printwire p TEMET M WW hen not printing Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BP X for any updates to this material http bpx okidata com Page 21 FA Service Guide ML390 ML391Turbo OKIDATA Chapter 2 Theory of Operation 2 2 02 Spacing Operation Refer to Figure 2 4 shown below 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 mechanism are as follows a DC motor with motor gear b Carriage frame stationary yoke and motor driver board included c Carriage shaft d Space rack e Sensor f Encoder disk 1 Spacing Operation The carriage frame on which the printhead and space motor are mounted moves along the carriage shaft in parallel with the platen When the spacing motor rotates counterclockwise
33. and 3P2 IBI 503 BI Ta use program ROM of Q2 SP 1 2 2 8 1 2 Wo relation for amy setting a e Do not change default setting 2 Driver Board SRXD 3 Operation Panel Board LEOP Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 104 OKID AT A Service Guide ML390 ML391 Turbo Chapter B Parts Listing 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 or 730 hours year The following codes are used to indicate the number of printers for which maintenance parts are ordered Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 5 6000 AT A Service Guide ML390 ML391Turbo Chapter B Parts Listing Upper Cover Assembly Figure 11 1 d a No Part No Description Q y Remarks ODA 1 4PP4128 1186P1 Cover Upper N 1 For ML390 Turbo 53076501 1PP4128 1231P1 Cover Upper W For ML391 Turbo 53076601 1PA4094 7308G11 Guide Sheet Assy W 1 ForML391 Tu
34. bly Disassembly 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 Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 36 OKID T Service Guide ML390 ML391Turbo al A A Chapter 3 Assembly Disassembly 3 1 Precaution for Parts Replacement 1 Remove the AC cable and the interface cable before disassembling or assembling a Turn off the AC power switch Remove the AC input plug of the AC cable from the receptacle Remove the AC cable from the inlet on the printer b To 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 remove unnecessary parts and limit the disassembly area as much as pos sible 4 Use the designated service tools 5 Carry out disassembly in the prescribed sequence otherwise damage to the parts may result 6 It is advisable to temporarily install screws snap rings and other small parts in their original positions to avoid losing them 7 Whenever handling the microprocessors ROM RA
35. ca Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 95 OKID AT A Service Guide ML390 ML391 Turbo uw Chapter 6 Troubleshooting and Repair 3 Homing does not end normally a Homing does not end normally Yes Ma a Check around space motor to repair the mechanism Space rack nbbon feed assembly back up oler carnage frame Support protector and nbbon protector a Hemedied Mo Yes End Heplace space motor eszy amp Heplace space motor assy Hemedied Ma Yes End x Heplace carriage cable amp Henmedied Mo Yes End Replace Driver Board x Hemedied Mo Yes 4 End Replace Gontml Power Supply Board Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 96 OKID AT A Service Guide ML390 ML391 Turbo Chapter 6 Troubleshooting and Repair 4 Paper jam while paper insertion r Paper jam while paper ireertian Jam 1 Check the ribbon protector Check the pull up roller cower iz closed property Pul up roller cower 7 Ribon Protector Papel Jam 2 winked paperi Check amund pressum moler mechanism Front pressure springs are narmw 3 pos wide 5 pos mounted pmpearhy or mot Tension af all af front pressure mler is proper
36. ch is attached to the under side of the carriage cover will connect with the contact of the space motor PC board The printer will reduce the printing speed automatically to ensure that adequate printing pressure is maintained for multipart paper And the adjusting cam adjusts the headgap toward left and right side in accordance with the guide rail up and down as a position of the left end of it wo o o ___ G arriage shaft Frinthead qu f zd Adjusting zc mew Adjusting Ewer Idler gear Adjusting gear Fangs fmm 5 ta 1 n Adjusting zc mew eee B Adjusting cam EN ON E wo GOW 4 1 ma uide rail Widens Fangs fmm 1 ta 5 i Figure 2 5 Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 3 FA Service Guide ML390 ML391Turbo OKIDATA Chapter 2 Theory of Operation 2 2 04 Ribbon Drive Refer to Figure 2 6 shown below 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 Ribbon Cartridge An endless ribbon with a single direction feed is used Ink is supplied from an ink tank which is built in to the ribbon cartri
37. com Page 62 OKIDATA Service Guide ML390 ML391 Turbo Chapter 4 Adjustments 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 Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 3 6000 AT A Service Guide ML390 ML391 Turbo re Chapter 4 Adjustments 4 1 1 Gap between the platen and the printhead No Item Specification Drawing Adjustment method 4 1 1 Gap between the It shall be measured at 3 points the platen and the left end the center and the right end printhead of the platen 1 Parallelism Variation of value Adjustment method adjustment at the left the center and the 1 Gap between the platen and the right shall be less printhead at the left end and the then 0 02 mm right end shall be adjusted by rotating the adjust cam 2 Set the adjust lever at the Range 1 Press the adjust gear downward in direction A to push the adjust gear and the adjust gear out of mesh 2 Initial adjustment 041 0 03 mm 3 Adjust the gap by rotating the adjust screw in direction B or C while the adjust lever and the adjust gear are disengaged 4
38. data com Page 114 OKIDATA Service Guide ML390 ML391 Turbo Chapter C RS 232C Serial Interface Board C2 2 02 RS 232C Interface The DTR SSD TD and RTS signals output by the 80C51 are converted to RS 232C signals by line driver SN75188 Q1 and sent to the interface In addition signals DSR CTS CD and RD on the RS232C interface are converted to TTL level by line receiver SN75189 Q2 and input to the 80C51 Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BP X for any updates to this material http bpx okidata com Page 115 OKID TA Service Guide ML390 ML391Turbo uF 4 Chapter C RS 232C Serial Interface Board C2 3 Communication Procedure Flowchart C2 3 01 Mode A Figure C 2 2 Ready Busy Rece wed one character Ma Yi E DSR valid Yes oe Yes es Ma Buffer overflow Tes Ma Mao eror Stare the mcened character in buffer Store 40 H in buffer the printer in DESELEC state or t the paper loy Yes E En butter space zz5e B Er buffer space during Se ve time out Ma Ma ES Tum an the S SD signal Yes Tum off the S SD signal em Mo Qutput ane character fmm the bute rto printer Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 116 OKI
39. dge 2 Ribbon Feed Operation When the space motor is activated the ribbon gear rotates The rotation is transmit ted via the ribbon drive gear assembly to the drive gear in the ribbon cartridge thus moving the ribbon The feed direction of the ribbon is maintained by switching the rotational direction of the gears in the ribbon drive gear assembly This ensures ribbon movement when bidirectional printing is used Ribbon carmdas Dir gear Bpa hicotor ssam Hy Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 4 OKIDATA Service Guide ML390 ML391 Turbo d Chapter 2 Theory of Operation 2 2 05 Paper Feed Operation Feeding of the paper is performed by turning the platen and the pin tractor which is driven by the Line Feed Pulse Motor The paper feed mechanism is made up of the items listed below a Pulse motor with gears b Decelerating gear c Platen d Tractor feed unit e Pressure roller Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 5 OKID AT A Service Guide ML390 ML391 Turbo 30 Pi Chapter 2 Theory of Operation Cut Sheet and Continuous Forms Switching Mechanism Refer to Figure 2 8 below Three different pape
40. e BPX for any updates to this material http bpx okidata com Page 65 000 AT A Service Guide ML390 ML391 Turbo Chapter 4 Adjustments 4 2 Gap between the platen and the paper pan No item Specification Drawing Adjustment method Gap between the 1 0 5 see below Confirm followings platen and the paper pan 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 the gap between the platen and the paper pan at the front side shall be 1 0 5 mm Change lever 0 Bottom Hear p e fos RR x a 5 E H Flaten 1 i B 7 Paper pan a ues a X DEM Frietion De T T position 7 Rear Bottom position Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 66 OKID AT A Service Guide ML390 ML391 Turbo 3 Chapter 4 Adjustments 4 3 Gap between the platen and the pressure roller No Item Specification Drawing Adjustment method Gap between the see below Confirm followings platen and the pressure roller 1 When the change 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 platen and the pr
41. ead 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 control board ru ae a e a E D 2 Le n B r u a 5 M 24 Figure 2 2 Arrangement of the head pins View from the tip of the printhead 1 Printhead Configuration The printhead is composed of the following parts a Wire guide b Spring assembly Wire Armature Spring Yoke Spacer c Magnet assembly Magnet core coil Yoke d Printed circuit board e Fin 2 Operation of Printhead Refer to Figure 2 3 shown below 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 character to be printed is detected a current flows through the coil When the coil is activated the magnetic flux caused by the permanent magnet between the armature and the core is canceled to eliminate the attraction force The armature is driven 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 dot on the paper c After the character has been printed the armature is magnetically attracted again and the print wires are again conce
42. elease shaft 2 change arm lever 6 change gear shaft 7 2 There are 5 Rear pressure Spring Assemblies Use two pieces which have larger spring diameter on the right side Use three remaining pieces on the left side for ML391 Turbo 3 Make sure that the Release Shaft 2 will be on top of the Support spring 4 4 To assemble the Release Shaft 2 make sure that the protrusion of the switch lever 5 is in the U groove of the Release Shaft 2 Partner Exchange BPX for any updates to this material http bpx okidata com Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business 0 CHU Page 61 6000 AT A Service Guide ML390 ML391 Turbo Chapter 3 Assembly Disassembly 3 3 22 Switch Lever 1 Remove the upper cover see 3 3 4 43 2 Remove the change lever and gears see 3 3 17 44 3 Remove the paper pan see 3 3 19 i 4 Remove the rear pressure assy see 3 3 21 lt 5 Pull the Switch Lever toward you and remove it upward 6 To install follow the removal step in the reverse order Remark on assembly 1 At the time of the Switch Lever assembly make sure that the Micro switch on the Main Board works properly Switch lever switch lever zu 7 Micra switch Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata
43. erial http bpx okidata com
44. ess Partner Exchange BPX for any updates to this material http bpx okidata com ODA Qty Description Printer Unit Figure 11 3 1 of 2 Service Guide ML390 ML391 Turbo Chapter B Parts Listing OKIDATA Page 107 Assy N OO T ew OO e e pe Assy W NEN 7 NN Paper End Pressure F N OO MUT po oos e Pi Pressure F presser gee ro mme c pem c For ML391 Turbo 53349001 F pemr 3327G2 Roller Front For ML390 Turbo 50410901 Pressure Assy For ML391 Turbo 50410901 e presser genes uem er Lean er ener pae Rey 8 3PP4025 3320P2 Spring Leaf N 1 For ML390 Turbo 50923000 3PP4025 3507P2 Spring Leaf W ForML391 Turbo 50923102 3PP4044 5011P1 Lever Paper 1 50809301 End 10 _ 3PP4044 5013P1 Lever Sensor 1 A 50809401 11 4PP4025 3340P X GearChang 1 51228001 3PP4025 3341P1 Gear Tractor 1 51228101 BEIT 5020P 1 Tm For ML390 Turbo 50931401 Pressure R Ps For ML391 Turbo 50931401 4PP4044 5163P1 Pressure Ww oo For ML391 Turbo 50931501 Pressure W 3PP4044 5033P1 m E id 3 ffo ML390 Turbo 53349101 5 ForML391 Turbo 53349101 16 eoa aa a BOT Turbo 17 SPP4044 504P Lever Switch 50809601 18 4PP4044 5024P1 22 Gearlde o 51238651 19 2PP4044 5016P1 2 LeverChane 50809501 20 3PP4044 5023P1 Spring Reset 50931601 21 3PA4044 5110G2_ MotorLF
45. essure roller at the rear side shall be 3mm The front pressure rollers shall be pressed to the platen Ghange lever s Center friction H Hear Flaten E Paper pan Front pressure 7 roller Pressure roller Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BP X for any updates to this material http bpx okidata com Page 67 6000 AT A Service Guide ML390 ML391 Turbo V Chapter 4 Adjustments 4 4 1 Rotation of the push tractor To confirm The tractor gear shall rotate smoothly when the change lever is set at Friction position Change lever Center friction Push tractor Tractor gear slight backlash Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 8 60 AT A Service Guide ML390 ML391 Turbo Chapter 4 Adjustments 4 4 2 Backlash between gears Specification Drawing Adjustment method Backlash between Approx 0 05 to To confirm gears 0 11 mm There shall be slight backlash between gears to allow smooth rotation of gears Backlash 0 05 to 0 11 mm Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 9 6000 AT A Service Gu
46. for any updates to this material http bpx okidata com Page 30 OKID AT A Service Guide ML390 ML391 Turbo Chapter 2 Theory of Operation 6 Bottom Push Feed Operation Option Refer to Figure 2 13 below The bottom push feed of the continuous forms 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 i el um Haten gear Change gear Tractor change gear Tractor ide gear Tractor drive gear Figure 2 13 Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 31 OKID AT A Service Guide ML390 ML391 Turbo 30 FFE Chapter 2 Theory of Operation 7 Paper Clamp Mechanism Refer to Figure 2 14 below 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 Position of Open or cbse o Open or close of change ewer front pressure roller rear pressure roller SI EEEM S
47. g rri mal FA fel c HEE K Fm C HEC E LSI RESET Extema FM CHECK LSI nial Setting and VF Busy EA clear Carnage Homing LF Matar Phase Inrtializatan Seria Parallel U IF LF BLIS Y OFF VF ACE Send Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 13 c Service Guide ML390 ML391Turbo OKIDATA Chapter 2 Theory of Operation 2 1 04 Parallel Interface Control The parallel data input from the host to the interfaced LSI is latched to its internal register at the falling edge of the STROBE N signal At the same time the LSI 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 MPU of data reception The data is read upon receiving the RD N signal from the MPU When the data processing ends the BUSY signal is set to off and the ACK N signal in sent to request the next data When reception is impossible because the buffer is full the BUSY signal is sent to request stopping of data transmission Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 14 OKID AT A Service Guide ML390 ML391 Turbo Chapter 2 Theory of Operation 2 1 05 Print Cont
48. g 1 Data is not received 2 Data does not print or data is missing when printed 1 Lata t not recewed A protocol amp st 0 READ BUSY state and BUSY UNE amp in 55D state oscillation wawvetfjrm ss specified in Fiqum G 3 17 the aur NIU 4045 Tire Figure C 3 1 Mo Repl e the OSC Yes ls a RST signal in G3 is specified in Figure L 3 fi iy Figure 2 Ma heck the RST cimurt on the SEXG baar Yes Are ALE PSEN RD WR signals as specified in Figure C33 5 dens 120 rez _ si ALE ov si PSEM ow aM Sons ROWE 5y oy Figure 5 3 3 Mo HBeplee the Q3 Yes Are T1 SELEGT and INTO BLS signals low fever Mo Check Gd on the SERA board Yes Are HY and OY input to G1 Mo Replace defectwe component in 9 9 wok control circuit Yes ls pind 55D signal af High evel Mo Replace the Q3 Yes ls pin 11 SSD of 1 low level a Ho Replace the i1 or the OMNI Yes ls the AxD of G3 specified in Figure G 3 4 zw OTT Tt ST bit SP bit Si S50 al 1 Figur 3 4 Mo Beplee the Ge Yes Replace the Fi iata does not print or data 15 missing when printed Am RED and 55D of 3 az specified in Figure 3 4 Mo HBeplee the Ge Yes Are WR and BUS signals af 43 pin 3 az specified in Figue 3 57 Figur 5 3 5 a Mo HBeplee the Q3 Yes sthe af a BUS
49. heck sum erm Replace ROM on IF E E E Gee ror FF Board m9 esp o eee alam Ma reactimi Thor Regate LF Boa or lol le 11 1 nmm SS LED Blink pome OM OIE OFF LED Light up Table 6 3 272 5Spacrng ala mi r IPTiz rot amam ed r Replace space moror within in zpedfied tim ing r Replace F H cable r Replace Control Pona Gippy Excer d Print Head Pire Freed doze rot reh Chack the mechanism s homing alam to the hom e position led iz beo much Them iter iz open short Check the HH conre with Oy or short with zy Replace Prirt Heed r Replace F H cable r Repa Control Powe amp pply Board Print Head ip Pirt Heed Gap Signal open Replace P H cable A D alam r Replace Spec bitor A amy r Replace Control Poser Supply LED Bink 200re OM So0me OFF LED Lignts up Operaton panel board Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 90 OKID AT A Service Guide ML390 ML391 Turbo e BR Chapter 6 Troubleshooting and Repair 6 4 Connection Circuit Check for Printhead and SP LF Motor 1 Printhead oignal Connector pin number a a fa ja a M E m i m I m 3 3 ju m H 35 ll TEELE 5 la E a le E IE p
50. hy Wake sue af the fitting positon of change gear shaft change arm shaft and e ease shaft am comert Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 7 OKID AT A Service Guide ML390 ML391 Turbo J Chapter 6 Troubleshooting and Repair 5 Smearing Missing Dots s Does ALARM LED blink and display alamni Mo Yes See Tables 6 2 and 5 3 for tmubleshaoting information Replace Frinthead Henmedied Ma Yes a End Replace Driver Board Henmedied Mo Yes End amp Replace carriage cable or space motor asse mb b Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 98 OKID AT A Service Guide ML390 ML391 Turbo J Chapter 6 Troubleshooting and Repair 6 Faint or dark print the print head gap set Yes Mo Adjust the print head gap see section 5 Hemedied Mo Yes End Replace Printhead Henmedied Mo Yes End amp Replace Driver Board Hemedied Mo Yes End x Replace nbbon feed mechanism Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material h
51. ide ML390 ML391 Turbo V Chapter 4 Adjustments 4 5 1 Ribbon feed To confirm Ribbon shall be fed smoothly when the carriage is moved from side to side Hibbon feeding T MM R 250g or less without a rib Ribbon bon cartridge Load MEASURE ment portion cartridge Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 0 000 AT A Service Guide ML390 ML391 Turbo Chapter 4 Adjustments 4 5 2 Running load to spacing mechanism To confirm Make sure that the power is turned off at the time of measurement Hibbon feeding 250g or less without a rib Ribbon bon cartridge wg Load Meas m ME rnt portion cartridge Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 71 OKID AT A Service Guide ML390 ML391Turbo 4 Chapter 4 Adjustments 4 6 Engagement of the double gear and the LF motor idle gear of the Platen Assy 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 The idle gear stays in mesh with
52. ion of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 101 OKID AT A Service Guide ML390 ML391 Turbo Chapter 6 Troubleshooting and Repair 9 Malfunction of switch on operation panel g lulalfunction of switch on operation panel the GN of operation panel connected to the CMS on the Driver Board Yes Mo _ Connect the cable properly Replace Operation Panel Board x Rermedied Yes Mo End La Replace Driver Board Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 102 OKID AT A Service Guide ML390 ML391Turbo 30 Fr Chapter 6 Troubleshooting and Repair 10 Data receiving failure i Data ece iwing failure 5 the SEL LED blinking Ma Y ez a Pointer went into the print Suppress mode Wait until piner ecewes D 1 code or change the menu tem Print supprmezs Ineffectmie when the function t not required Is the IF RSz32807 Mo Yes To step amp Does the SEL LED light up Yes Mo e Press SEL key FRemedied Mo Yes Does the printer raceme data property Mo Yes 104 To step End Dizconrect WF cable Does the SEL LED light up Mo Yes Change menu iem l prirme to invalid or check for deftetiwe cable Replace Driver Board
53. lder assy 3 should be facing up when installing Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 50 6000 AT A Service Guide ML390 ML391 Turbo Chapter 3 Assembly Disassembly 3 3 11 Platen Assy 1 Remove the printhead see 3 3 1 5 2 Remove the ribbon protector see 3 3 2 i 3 Remove the pull up roller Assy see 3 3 3 3 4 Remove the upper cover see 3 3 4 i 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 upward by 90 7 Remove the platen Assy 4 from base frame 8 To install follow the removal steps in the reverse order ES 4 7 i ze re HE M S h aeu ANSA s B Me NW B vh bmi us 1 ST a Delos DS Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 51 OKID AT A Service Guide ML390 ML391 Turbo ini ta Chapter 3 Assembly Disassembly 3 3 12 Driver Board SRXD 1 Remove the upper cover see 3 3 4 i 2 Remove two screws 1 lift clamp 4 and release the driver board 2 and PCB sheet 5 3 Disconnect all cables from driver board 2 4 To install follow the removal steps in the reverse order
54. lications Contact Please address any comments on this publication to OKIDATA Training and Publications 532 Fellowship Road Mount Laurel NJ 08054 3499 Okilink Login Name Technical Training Internet Web Site okidata com Copyright Listing OKIDATA is a registered trademark of Oki America Inc OKIDATA est une marque d pos e de Oki America Inc Centronics is a registered trademark of Centronics Data Corporation Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 3 AUF A Service Guide ML390 ML391Turbo OKIDATA Chapter 1 Configuration 1 1 Standard Printer Configuration This printer consists of the following assemblies Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 4 7 te Service Guide ML390 ML391 Turbo OKIDATA Chapter 1 Configuration 1 2 Options 1 Cut Sheet Feeder Unit CSF Single Bin Cut Sheet Feeder 2 Pull tractor Assembly 3 Bottom Push Tractor Unit Narrow and wide versions available 4 Roll Paper Stand Narrow only 5 Serial Interface Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates t
55. nd the output current data from the LSI The data from the LSI is processed by a specific register contained in the LF motor driver to measure the overdrive time and to change the phase PHA SE A PHASE 6 FORWARD REVERSE Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 17 FA Service Guide ML390 ML391Turbo OKIDATA Chapter 2 Theory of Operation 2 1 07 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 LSI IC1 BU5148S sath contoller __ es o SS A 2 byte 15 bits 1 even parity bit command OPTXD is transmitted to the LSI BU5148S in synchronization with the OPCLK signal The LSI decodes this command and when it is found to be legal returns a 2 byte command response back to the LSI which includes data on Switch information LED status receive command ACK NAK and 1 odd parity bit Any transmission errors found cause the command to be reissued after the transmission of the OPCLR N signal 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 retumed before decoding the command Copyright
56. ning and Lubrication 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 Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 74 OKID AT A Service Guide ML390 ML391 Turbo Ww Chapter 5 Cleaning and Lubrication 1 Cleaning time Remarks 1 Turn off the power before cleaning 2 Make sure that paper dust will not fall inside of the machine Cleaning period 6 months of operation or 300 hours of operation whichever the earlier Cleaning points Carriage shaft and T Remove paper and ribbon dust Faper path Clean stains and dusts Faper End Sensor Hemoeove the dust on the Sensor Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 75 OKID AT A Service Guide ML390 ML391 Turbo Chapter 5 Cleaning and Lubrication 2 Lubricant Pan motor oil or equivalent PM Molicort or equivalent EM 30L Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any upda
57. o this material http opx okidata com Page 5 0 Service Guide ML390 ML391 Turbo OKIDATA Chapter 2 Theory of Operation 2 1 01 Summary Figure 2 1 shows the block diagram of the printer The control board is made up of the microprocessors peripheral circuits drive circuits sensors and interface connectors The power to the control board is supplied by the power board through the connector cord The power to other electrical parts is also distributed through the connectors within the control board Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 6 c Service Guide ML390 ML391Turbo OKIDATA Chapter 2 Theory of Operation 2 1 02 Microprocessor and the Peripheral Circuit Microprocessor Q7 67X640 This processor is a CMOS single chip computer with integrated peripheral device functions and a 16 bit MPU core all OKI original architecture The processor has a 20 bit address bus and a 16 bit data bus It is capable of accessing up to 1M word program memory and 1M bytes of data memory The following characteristics are also provided e Built in type data memory of 512 bytes e 8 bit 4 channel A D converter Y 1 e 16 bit automatic reload timer Y 2 e 8 bit serial port Y 2 e 8 bit parallel port 3 bitwise I O specification available And others The function of thi
58. or feed unit through the idle gear to feed the paper which has been set in the bottom tractor feed At the same time the switch lever turns on the bottom switch to confirm to the control board that you are in the continuous forms mode Figure 2 6 Condo Power Supply Azzembly Change Gear Shat Garelatian in blec han Ern Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 6 c Service Guide ML390 ML391Turbo OKIDATA Chapter 2 Theory of Operation 2 Cut sheet feeder operation Refer to Figure 2 9 below 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 When using cut sheet paper the change lever must be in the TOP position to grab the paper while disengaging the push tractor When the change lever is set to the TOP position the cut sheet is automatically fed in up to the print start position after pausing for the wait time stored in the menu Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 27 OKID AT A Service Guide ML390 ML391 Turbo Chapter 2 Theory of Operation 3 Continuo
59. printhead see 3 3 1 3 2 Remove the upper cover see 3 3 4 43 3 Remove the gear case Assy see 3 3 5 4 Remove the space motor see 3 3 7 i 5 Remove the space rack 3 3 8 i 6 Remove two screws 1 release the driver board 2 and PCB sheet 9 by lifting clamp 8 and disconnect cable from connector 3 4 5 6 7 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 slightly the car riage cable 7 when assembling into the fasteners 2 Make sure that the paper end lever A will not contact the Paper end Sensor 0 when mounting the Driver Board Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 9 6000 AT A Service Guide ML390 ML391 Turbo ini ta Chapter 3 Assembly Disassembly 3 3 10 Backup Roller Holder Assy 1 Remove the printhead see 3 3 1 lt 3 2 Remove the upper cover see 3 3 4 43 3 Remove the gear case Assy see 3 3 5 4 4 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 5 To install follow the removal steps in the reverse order Note Small round hole with metal tip on back up roller ho
60. r 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 marked TOP Operation The driving force of the platen gear R is transmitted to the idle gear by setting the change lever to the TOP position However this causes the idle gear to be disengaged from the change gear leaving it free At this time the pressure rollers at the rear and the front are pressed securely to the platen to feed the cut sheet At the same time the switch lever positions between the rear switch and bottom switch to confirm to the control board that you are in the cut sheet mode In the cut sheet mode the control board automatically feeds the sheet up to the print start position after pausing for the wait time stored in the menu b REAR Continuous forms 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 tractor shaft and the continuous forms is fed from the push tractor At the same time the switch lever turns on the rear switch to confirm to the control board that you are in the continuous forms mode c BOTTOM Continuous forms from bottom feeder option When the change lever is set in the BOTTOM position the rotation of the platen is transmitted to the drive gear of the bottom tract
61. r to the REAR position Pull racer Figure 2 11 Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 9 6000 AT A Service Guide ML390 ML391 Turbo wr Chapter 2 Theory of Operation 5 Pull tractor mechanism option Refer to Figure 2 12 below Bottom feed of continuous forms 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 The rotation of the idle gear is transmitted to the drive gear and continuous forms forms are fed by the pull tractor being rotated through the sheet feeder shaft 1 a FL E oa U G e R QT ad 3 Jr Sheet feedei E a udo CA wA dE INT E TE 95 Bos E Pay wh 2 UE we de t 4 r a x 1 1 ae x a ME f 2 i i 2 ET 1 E Er a 0 Ub 1 T ar a ND 1 8 Dri J 3 ae ut auf Tru Mo o5 8 1 TI ak a i o a LER A o E E de gy h Ex A a gs M e KAA A A A 0 Lr 1 T n e UM t 1 i CREER VA EE pA 3 e N Do Wa wa 3 LF mot x E aic 3 ux EQ I Fal Pon Figure 2 12 Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX
62. rbo 51009510 12PA4128 1241G1 Cover Access Assy W For ML391 Turbo 53076801 1PP4128 1188P1 Cover Acoustic N For ML390 Turbo 53076901 4PP4128 1233P1 Cover Acoustic W For ML391 Turbo 53077001 Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com ODA 91902220 Qty Description Knob Platen Printer General Assembly Figure 11 2 3PP4025 2871P21 Service Guide ML390 ML391 Turbo Chapter B Parts Listing OKIDATA Page 106 Control Power supply Driver Board 0 4 4YA4042 1516G4 PCB LEOP 4 1 55081104 5 SPP4044 5360G2 Operator Panel Assembly 111 50221902 6 ACcordfori2 V 1 frODA 56631804 pf lACcordfo220V fM 56631901 Printhead Assy 24 1 0114701 J 8 Fuse 125V 25A 2 For120V___ 40085501 NN 1 For 230 240V 563072001 9 enS 56415601 4YB4042 1551P1 Fuse 250V 1 25A 4YB4049 7105P1 ML390 Turbo 120V UNE 4YB4049 7106P1 Transformer ML390 Turbo 230 240V T Transformer ML391 Turbo EI m 120V 4YB4049 7106P2 Transformer ML391 Turbo sienn 230 240V 3PB4050 3429P1 PCB plate d b1022801 40045601 FG plate d b1023501 1 1 1 1 1 2 1 1 1 Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Busin
63. rial http bpx okidata com Page 55 OKID AT A Service Guide ML390 ML391 Turbo as Chapter 3 Assembly Disassembly 3 3 16 Transformer Assy 1 Remove the upper cover see 3 3 4 43 2 Remove AC inlet 1 and AC switch 2 from the frame guide 3 Disconnect the cable 3 from the connector 4 on the Control Power Supply Board 5 4 Remove a screw 6 and disconnect ground cable 7 5 Remove two screws 8 and shift the transformer Assy 9 to the left and remove it Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 56 OKID AT A Service Guide ML390 ML391 Turbo j Chapter 3 Assembly Disassembly 3 3 17 Change Lever and Gears 1 Remove the upper cover see 3 3 4 43 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 the change lever 3 4 To perform mounting follow the reverse procedure of removal Remark on assembly 1 To insert the change lever into the Change Gear Shaft 6 match the flat surface D cut Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 57 6000 AT A Service Guide ML390 ML
64. rinthead e No spacing operation 2 e Homing does not end 3 opace Motor Carriage normally Cable Control Power oupply Board Driver Board Spacing Mechanism Trouble during printing Paper jam while paper ee Pressure Roller insertion Mechanism Pull Up C ex Cover Smearing Missing dots 5 Printhead Driver Board Space Motor Carriage Cable Faint or dark print Printhead Ribbon Feed Assembly Driver Board mand ae Space Motor Driver Board RE Driver Board ENEEENN S on operation panel Data receiving failure Driver Board I F Board I F Cable Menu Setting Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 89 6000 AT A Service Guide ML390 ML391 Turbo Chapter 6 Troubleshooting and Repair 6 3 Lamp Display 1 Printer mode display Table 67 LED CON DITESH CONTENTS i HOC FA Fl 150 Pl E cut sheet or botiem vem leveri meti TOP et spedted poston while paperiz position lever ala rn ereedyinzered from resror Check ear sna r lerr better Replace Control Board Cut sheet could rot be OPERATOR ejected i A LA Rt SEED IS Cut sheet could rot be fed ind prevail Press SEL bey Weit uni it iz cooled Pont Head Print head
65. rol Print data is transmitted as parallel data HEAD1 HEAD24 from LSI to print head LSI generates print timing and drive time Print Head HEAD DRIVE This CHART LIT1 OTe u BLESS DRIVE CURRENT Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 15 OKID AT A Service Guide ML390 ML391 Turbo PP Chapter 2 Theory of Operation Print Compensation Control The print compensation can be made as shown below a Voltage compensation See 2 1 8 Alarm Circuit b Temperature compensation See 2 1 8 7 Alarm Circuit c Pin stroke compensation Print Head Azzhown in the drawing left the stake length up to the platen i different for each pin Tire Pin coi current Fin 1 4 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 Mode Compensation According to the thickness of the printing medium the print mode is compensated as shown in the table below qu ee ame me fo m sone Drive time ke ethers at each step Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 16 FA Service
66. roller holder IL n EM 30L A4 EM 30L ed ub d Release shaft protruding portion 2 portions ElM 3 L A ys 1 ud 5 35 Shaft 7 4 ls EN 1 im 7 Bearing portion of front roller TT am holder and pressure roller J EM 30L B Fear roller holder Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 4 6000 AT A Service Guide ML390 ML391Turbo Chapter 5 Cleaning and Lubrication T Pull up roller Assy All bearing portions of pull up roller shaft and pull up roller frame Eh 3oL B Gear and post Elv S L A Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 85 6000 AT A Service Guide ML390 ML391 Turbo e fers Chapter 5 Cleaning and Lubrication 8 Main chassis Assy Grease portion rl 3 podos W 5 podore rear side EM SaL A N CO Mae Ay M MLzan Turbo E ary ope ML331 Turbo i Lo arase portion at nb E M 3 ponore W 13 porione J EM 30L Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 86 OKID AT A Service Guide ML390 ML391 Turbo Chapter 5 Cleaning and
67. rts Figure 11 5 Ful Tractor Bottom Tractor YF Boa rl 4PA4025 3608 Hoe n amp Bottom EM 50098001 G1 Assy 2 3603 mE fa amp Bottom d cm 50097901 Assy 3 PPT 1239 Cover EN i ML390 53077201 Turbo SPPE 1243 cud Tractor Assy For ML391 53077301 G1 Turbo E 1277 is Bottom Push T 3 51902301 G1 eer rer erem T erem emer peer eee Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 111 OKIDATA Service Guide ML390 ML391Turbo Chapter C RS 232C Serial Interface Board APPENDIX C RS 232C SERIAL INTERFACE BOARD C1 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 Two protocols are available printer Ready Busy and X ON X OFF modes Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 112 OKID AT A Service Guide ML390 ML391 Turbo P Chapter C RS 232C Serial Interface Board C2 Operation Description C2 1 Elemen
68. s 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 Clock autizproeided when Tie orginal excatat on is zeeckted Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 12 6000 AT A Service Guide ML390 ML391 Turbo 3 B Chapter 2 Theory of Operation 2 1 03 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 LSls When resetting ends the program starts and the LSIs are reset by MPU via LSIRST N Reset operation by I PRIME starts program to initialize but does not 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 establishes the interface signals P I F ACK P signal sending and S I F BUSY N signal off and lights the SELECT lamp to inform the ready state for receiving to the host side and ends the initialize operation in t 4 RFU RESET MF LI Initial Setin
69. s microprocessor is to provide a central mechanism for the entire printer by executing the control program through the LSI and driver circuits Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 7 OKIDATA Service Guide ML390 ML391 Turbo t RJ Chapter 2 Theory of Operation Printer Block Diagram Figure 2 1 a eee eg ee Y Serial er z E ME Lu LL SHAPONSDT 16 SE f 22 a u ET ila 5 cnp cocer lr E y T 1 Zr 1 xx Bj amp EY lt r Wo 12255 MHz F AI Woc Level TSD SEL N Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 8 OKID AT A Service Guide ML390 ML391 Turbo Chapter 2 Theory of Operation Program ROM This is a 256 X 16 bits 4M bit MAX EPROM with the control program for the printer stored The MPU executes instructions under this program The program ROM is assigned to the program memory area of the MPU and is fetched by the PSEN signal of the MPU The following shows the operation of the memory access ww TTK TTY Por M ON UN a rn FS EHH Em P aum NM Au MM a Program Program Program L D15 Copyrigh
70. s not been fed in the feeding operating operation becomes ineffective thus resulting in the feeding jam Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 34 OKID AT A Service Guide ML390 ML391 Turbo Chapter 2 Theory of Operation 2 2 08 Paper Park Function Continuous Forms Continuous forms 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 paper end occurs or 19 inches maximum have been fed 3 The paper is fed in reverse to leave the paper on the push tractor or bottom tractor Paperend detector Reverse LF tom F E Sensor to tracinr Bed assy Fee LF unil paperend or 13 inches TEZ Alarm LED lights up when P E is not detected after 19 inches reverse feeding Operator can press SEL key to turn off the ALARM LED then press PARK key to continue park function This operation is required when the length of paper for parking is more than 19 inches Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 35 OKIDATA Service Guide ML390 ML391 Turbo Chapter 3 Assem
71. sed Operational procedure When Using Cut Sheet 1 Set the change lever to the TOP position See Figure 2 17 below 2 Insert a sheet 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 4 When the default is selected the sheet of paper is feed in up to the position 0 35 inches first dot position from the upper end of the sheet However the 0 tear off mechanism allows the printing at the front end of the sheet by changing the TOF position Sheetseting i mE Tire aut PE y Dietecton acer b Tire selected an Tie meni 7 7 LF acdon Figure 2 17 When Using Continuous Forms 1 Set the change lever either to the rear side or the bottom side position See Figure 2 17 above 2 Set a sheet of paper either to the push tractor or the bottom tractor 3 Press the FF LOAD switch 4 The LF motor starts its operation to feed the paper up to the print start position 5 The paper is fed in up to the TOF position Factory default 0 35 inches from the top Push down the FFA swith 37 i Deecton of he sheet supplied LF aon 1 v Line ed about 3 inches unt te detection ofthe sheet supplied When the FF LOAD switch is pushed down the LF motor feeds in the sheet about 3 inches When the LF motor completes the operation and the sheet ha
72. signals atar pins 2 9 the same s that of DB 7 when WR signal is started Mo HBeplee the Q7 Yes s4 pin of C6 identical to WR signal in Figure L 3 Mo HBeplee the Q5 e Yes Gheck G7 LS 10501042 in th SAAD contol POE Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 118 c Service Guide ML390 ML391Turbo OKIDATA Chapter C RS 232C Serial Interface Board C3 3 Local Test C3 3 1 Circuit Test Mode C3 3 1 1 Setting 1 Diagnostic test set by menu 2 Test connector Connect the test connector shown in Figure C 3 6 to the interface connector Test Connector Connection Diagram Figure C 3 6 Equivalent ta Gannon Setup Test Hold SHIFT and SEL switches to enter Menu Mode Move to the Serial I F Options and continue on the Diagnostic Test option Change this option to Yes This will setup the Diagnostic Test Program Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 119 6000 AT A Service Guide ML390 ML391 Turbo a fers Chapter C RS 232C Serial Interface Board C3 3 1 2 Function After the settings outlined in Section 3 3 1 1 are completed and power is turned on the serial interface checks the message
73. t 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 39 6000 AT A Service Guide ML390 ML391 Turbo Chapter 3 Assembly Disassembly How to Change Parts This section explains how to change parts and assemblies appearing in the disassembly diagram below Porter urit 33 1 Pinhead 33 3 Pull up roller assy 33 2 Hbben protector S344 Upper cover access cover and sheet gude 33 5 Gearcase assy 35 PO connector 3 3 7 Space mowr and qude rllerassy 3 35 Space rack 3 39 Carriage cabs 3 340 Back up mler Felder assy 33 11 Patenassy 3 3 19 Paperpan 353 12 Driver board SERAD 3 343 LF motor 3 318 Gamage shaft 353 14 Cperation panel POB LEOP 33 15 Contmd Power supply board SEC 33 156 Trarefommer assy 33 17 Ghangeleverand gears 3 320 Rear actor assy 3 321 Rear pressure assy 3 322 Zameh lever Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 40 OKID AT A Service Guide ML390 ML391 Turbo Pers Chapter 3 Assembly Disassembly 3 3 01 Printhead 1 Open the access over 2 Pull up and rotate the head clamp 1 to unclamp the printhead 2 as shown fig 3 3 1 see below 3 Disconnect the printhead 2 from PC connector 3 4 To
74. t 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 9 OKID AT A Service Guide ML390 ML391 Turbo Chapter 2 Theory of Operation RAM MSM51C464A 80RS The RAM is CMOS dynamic RAM with 64K 4 bit 2 configuration 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 MPL FAM 1 fx Glec kout T1 Tg T3 Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 10 6000 AT A Service Guide ML390 ML391 Turbo SU FN Chapter 2 Theory of Operation 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 MP LI EEF Frati P24 Di Po cs EEDraLIT P Pos Dra EEC LiF Write cycle timing WRITE Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 11 c Service Guide ML390 ML391Turbo OKIDATA Chapter 2 Theory of Operation Large Scale Integrated Chip LSI Thi
75. t Description 1 80C51 with MASK ROM An eight bit microprocessor controller that controls the following a Serial interface protocol and data transfer through a serial port b Message buffer c Transmission of parallel data to the printer d Serial interface control program 2 SN75189 An RS 232C standard line receiver 3 SN75188 An RS 232C standard line driver 4 HM6264 An 8192 byte static RAM used as a message buffer C2 2 Circuit Description A block diagram is shown in Figure C 2 1 Block Diagram Figure 6 2 1 NI Wi eZ Boer Recener Serial data wp contol lire IIT poi i AU V AG SUp phy cim uit 94 7 Eus line 35 BV m Gantral line Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 113 OKIDATA Service Guide ML390 ML391 Turbo Chapter C RS 232C Serial Interface Board C2 2 01 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 Initialization consists of setting the 80C51 timer and setting the serial mode Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx oki
76. tes to this material http bpx okidata com Page 76 OKID AT A Service Guide ML390 ML391 Turbo Chapter 5 Cleaning and Lubrication 3 Amount of lubricant Medium amount A Apply three to four drops of oil or 0 008 inch 0 2 mm thick grease e Small amount B Apply one drop of oil 0 006 0 002 g Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http opx okidata com Page 77 OKID AT A Service Guide ML390 ML391Turbo wr Chapter 5 Cleaning and Lubrication 4 Areas to Avoid Ne Do not vorne Remarks 1 Platen assembly To prevent stained paper rubber face and illegal paper fec Pressure roller rubber To prewent stained paper Pay attention motto put face the grease on the rubber face of the pressure roller 3 CaTiage shaft To stabilize ca riage traveling kag 4 Ink ribbon To prevent buring of print image 5 Pin tractor To prevent stained paper a Flexible ca ble To prevent bose connection and crack T uctor PCB To prevent bose connection 5 Connecter terminals To prevent bose connection Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 8 OKIDATA Service Guide ML390 ML391 Turbo Fa Chapter 5 Cleaning and Lubrication 5 Lubrication points
77. the driving force is transmitted to the motor gear As the motor gear rotates the carriage moves from left to right Mechanically it is designed in such a way that for every revolution of the DC motor the carriage frame moves 0 8 inch 20 32 mm At the same time the encoder disk rotates together with the motor and passes the sensor The position of the carriage frame can be determined by counting the inter rupts detected by the sensor In the same way the rotation of the space motor can be recognized and controlled by measuring the cycle of interrupts detected by the sensor Print Head Carizg shaf Camizge fame Buide rail Figure 2 4 Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 22 OKID AT A Service Guide ML390 ML391 Turbo w Chapter 2 Theory of Operation 2 2 03 Head Gap Adjusting Refer to Figure 2 5 shown below 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 If the adjusting gear is pushed 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 j f the contact whi
78. the platen gear L and the bias gear and not locked The bias gear and the platen gear shall be staggered by one teeth as shown in the drawing LF Motor Flaten gear iL idle gear 1 Blas gear Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 72 OKID AT A Service Guide ML390 ML391 Turbo Per Chapter 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 lubricating 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 vacuum cleaner 3 Places to be cleaned Table 5 1 lists the places to be cleaned Table 5 1 Place to be daeared earning procedure Carnage shaft and te vicinity Remove paper waste and wipe off Paper travel Surface Stain dust nbbon waste etc Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 73 OKIDATA Service Guide ML390 ML391 Turbo Chapter 5 Clea
79. ttp bpx okidata com Page 9 OKID AT A Service Guide ML390 ML391 Turbo Chapter 6 Troubleshooting and Repair 7 Ribbon feed trouble T Ribbon teed tmuble Hhemewe the ribbon cartridge amp s carriage to left and night e Does the ribbon diwe shaft mtatae Mo Yes Change nbbon cartridge Remove nbbon feed mechanism amp hove carmiage to left and night amp Does the ribbon diwe shaft rotate Mo Yes Heplece ribbon feed mechanism Replace space motor assy Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 0 OKID AT A Service Guide ML390 ML391 Turbo Chapter 6 Troubleshooting and Repair 8 Line feed trouble 2 Line feed trouble Turn the power off and mtae the platen manually Doe the platen ptite zmoaothh Yes Mo the plan gear iL boken Mo Yes Replace platen assembly ls the LF motor idle gear broken Mo Yes Replace the LF motor assembly or LF idle gear ls the plan gear Ai de gear or change gear broken Mo Yes Replace the gear Set change lever to the mar position Does the platen rotate smoothly Mo Yes Replace tractor feed assembly s Heplaee LF motor 352e mb hr Fe place LF motor assem bh He med ied Ma Y ez u End Replace Driver Board Copyright 1997 Okidata Divis
80. us Forms Operation Rear See Figure 2 10 below 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 forms Pull tarer Figure 2 11 Copyright 1997 Okidata Division of OKI America Inc All rights reserved See the OKIDATA Business Partner Exchange BPX for any updates to this material http bpx okidata com Page 8 A Service Guide ML390 ML391Turbo OKIDATA Chapter 2 Theory of Operation 4 Push and pull tractor mechanism Option Refer to Figure 2 11 below 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 forms to the push tractor and pull tractor The rotation of the platen is transmitted to the push tractor and the pull tractor Continuous forms 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 the REAR position setting the forms to the push tractor to feed 2 Set the paper which is fed in front of the platen to the pull tractor 3 Set the change lever to the TOP position and feed paper using the platen knob 4 If paper slack is removed set the change leve

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