Oki ML421 Maintenance Manual

Oki Data CONFIDENTIAL ML420/421 PRINTER Maintenance Manual ODA ...

PREFACE This maintenance manual describes how to maintain the ML420/421 printer in the field. This manual is for customer engineers. For further information, refer to the Users Manual for handling or operating the equipment. The relation between the destination point and the model name of this printer is as ...

Contents 1. CONFIGURATION ...............................................................................................6 1.1 Standard Printer Configuration ............................................................................................ 6 1.2 Options............................................ ...

3.3.20 Rear Tractor Assy ................................................................................................. 76 3.3.21 Rear Pressure Assy .............................................................................................. 77 3.3.22 Switch Lever ...................................... ...

1. CONFIGURATION 1.1 Standard Printer Configuration This printer consists of the following assemblies: Figure 1-1 Configuration Upper cover Access cover assy Platen knob Sheet guide assy Control board Power supply board Transformer assy Pull-up roller assy Main chassis assy Operation panel assy ...

1.2 Options (1) Cut sheet feeder unit (CSF) (Narrow and wide versions available) Dual-bin CSF Single-bin CSF (2) Pull-tractor assy Attachment assy Attachment assy ...

(3) Bottom push tractor unit (4) Roll paper stand (Narrow only) (5) RS232C Serial interface board ...

2. THEORY OF OPERATION 2.1 Electrical Operation The electrical operation of the printer circuit is described in this section. 2.1.1 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 conne ...

Figure 2-1 HTEMP 14.456 MHz 4 POWLEV HTEMP HEADGAP SPTEMP A/D PE-SENSOR OPERATION PANEL Serial Alarm -circuit HD alarm Over-V alarm Over-V alarm FAN alarm Power-off Transformer Rectifier circuit 50 volt 12 volt 5 volt 42V -8V 3.3V 5VS Reset circuit I/F-IPT Print-IPT EEPROM 1Kbits Microproce- ssor ADDRESS ...