Oki ML490 Maintenance Manual

Also see for ML490 Series: User guide Installation Installation User guide Safety & warranty

Contents

Oki ML490 Maintenance Manual Manual pdf 4 page image

42114101 Rev.1 4 /Contents1. CONFIGURATION ...............................................................................................61.1 Standard Printer Configuration ............................................................................................ 61.2 Options ................................................................................................................................. 72. THEORY OF OPERATION ..................................................................................92.1 Electrical Operation .............................................................................................................. 92.1.1 Summary ................................................................................................................. 92.1.2 Microprocessor and the peripheral circuit ............................................................... 92.1.3 Initialization ........................................................................................................... 162.1.4 Interface Control ................................................................................................... 172.1.5 Print Control .......................................................................................................... 202.1.6 SP/LF Motor Control ............................................................................................. 222.1.7 Operation Panel .................................................................................................... 252.1.8 Alarm Circuit ......................................................................................................... 272.1.9 Power Supply Circuit ............................................................................................. 302.2 Mechanical Operation ........................................................................................................ 312.2.1 Printhead mechanism and operation (See Figure 2-2.) ........................................ 312.2.2 Spacing operation (See Figure 2-4.) ..................................................................... 342.2.3 Head gap adjusting (See Figure 2-5.) ................................................................... 352.2.4 Ribbon drive (See Figure 2-6.) .............................................................................. 372.2.5 Paper feed operation ............................................................................................ 392.2.6 Paper detection mechanism (See Figure 2-14.) ................................................... 492.2.7 Automatic sheet feed ............................................................................................ 512.2.8 Paper park function (continuous paper) ................................................................ 533. ASSEMBLY/DISASSEMBLY ..............................................................................543.1 Precaution for Parts Replacement ..................................................................................... 543.2 Service Tools ..................................................................................................................... 553.3 Disassembly/Reassembly Procedure ................................................................................ 563.3.1 Printhead ............................................................................................................... 583.3.2 Ribbon Protector ................................................................................................... 593.3.3 Pull-up Roller Assy ................................................................................................ 603.3.4 Upper Cover Assy, Access Cover Assy and Sheet Guide Assy ........................... 613.3.5 Gear Case Assy .................................................................................................... 623.3.6 PC Connector ....................................................................................................... 633.3.7 Space Motor, Guide Roller Assy ........................................................................... 643.3.8 Space Rack ........................................................................................................... 653.3.9 Carriage Cable ...................................................................................................... 663.3.10 Backup Roller Holder Assy ................................................................................... 673.3.11 Platen Assy ........................................................................................................... 683.3.12 Control Board (TFS) .............................................................................................. 693.3.13 LF Motor ................................................................................................................ 703.3.14 Operation Panel Board (LEOP) ............................................................................ 713.3.15 Power Supply Board (TPW) .................................................................................. 723.3.16 Transformer Assy .................................................................................................. 733.3.17 Change Lever and Gears ...................................................................................... 743.3.18 Carriage Shaft ....................................................................................................... 753.3.19 Paper Pan ............................................................................................................. 76