Oki ML420 - Page 5

42113901TH01 Rev.3 5 /
Oki Data CONFIDENTIAL
3.3.20 Rear Tractor Assy ................................................................................................. 76
3.3.21 Rear Pressure Assy .............................................................................................. 77
3.3.22 Switch Lever ......................................................................................................... 78
4. ADJUSTMENT ...................................................................................................79
5. CLEANING AND LUBRICATION .......................................................................87
5.1 Cleaning ............................................................................................................................. 87
5.2 Lubrication ......................................................................................................................... 88
6. TROUBLESHOOTING AND REPAIR ................................................................95
6.1 Items to Check Before Repair............................................................................................ 95
6.2 Troubleshooting Table ....................................................................................................... 95
6.3 Lamp Display ..................................................................................................................... 96
6.4 Connection Circuit Check for Printhead and SP/LF Motor............................................... 100
6.5 Troubleshooting flow chart............................................................................................... 102
APPENDIX A PCB LAYOUT ...............................................................................114
APPENDIX B SPARE PARTS LIST ....................................................................115
APPENDIX C RS-232C SERIAL INTERFACE BOARD (OPTION)....................126
1. GENERAL............................................................................................................................ 126
2. OPERATION DESCRIPTION .............................................................................................. 126
2.1 Element Description .................................................................................................. 126
2.2 Circuit Description ..................................................................................................... 127
2.2.1 Operation at power on .................................................................................... 127
2.2.2. RS-232C interface .......................................................................................... 127
2.3 Communication Procedure Flowchart ....................................................................... 128
2.3.1 Mode a .......................................................................................................... 128
2.3.2 Mode b .......................................................................................................... 129
3. TROUBLESHOOTING FLOWCHART ................................................................................. 130
3.1 Before Repairing a Fault............................................................................................ 130
3.2 Troubleshooting ......................................................................................................... 130
3.3 Local Test .................................................................................................................. 133
3.3.1 Circuit test mode ............................................................................................ 133