OKIDATA ML320 Turbo Service Manual

Dot matrix printers

Hide thumbs Also See for ML320 Turbo:

Service manual (294 pages)

User manual (60 pages)

Quick manual (2 pages)

Table Of Contents

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

Table of Contents

Quick Links

Troubleshooting

Summary of Contents for OKIDATA ML320 Turbo

Page 1 Thank You for purchasing this Factory Service Manual on EBAY from PCTECHINFO! Click Here for more Factory Service Manuals for other Computer and Printer / Copier Manufacturers from PCTECHINFO!
Page 2 300 dpi, which is ideal for printing, but does not view on most displays well. Okidata is a registered trademark, and OkiPage is a trademark of Oki Electric Industry Co., Ltd. HP, LaserJet and PCL5e are trademarks of Hewlett-Packard Co. Adobe and Acrobat are trademarks of Adobe Systems Incorporated.
Page 3: Table Of Contents
Table of Contents Page Service Guide ML320/321Turbo 0 About This Manual Front Cover 1 Configuration 1.1. Standard Printer Configuration 1.2 Options 2 Operation Description ..2.1.1 Summary ..2.1.2 Microprocessor and the Peripheral Circuit ..2.1.3 Initialization ..2.1.4 Parallel Interface Control ..2.1.5 Print Control ..2.1.6 SP/LF Motor Control ..2.1.7 Operation Panel ..2.1.8 Alarm Circuit...
Page 4 Table of Contents Page ..3.3.15 Control/Power Supply Board (SDCT) ..3.3.16 Transformer Assy ..3.3.17 Change Lever and Gears ..3.3.18 Carriage Shaft ..3.3.19 Paper Pan ..3.3.20 Rear Tractor Assy ..3.3.21 Rear Pressure Assy ..3.3.22 Switch Lever 4 Adjustments 4. ADJUSTMENT 5 Periodical Maintenance 5.1 Cleaning 5.2 Lubrication 6 Troubleshooting...
Page 5: Configuration
Page: 2 Service Guide ML320/321Turbo Chapter 1 Configuration 1.1. Standard Printer Configuration This printer consists of the following assemblies:...
Page 7: Options
Page: 3 Service Guide ML320/321Turbo Chapter 1 Configuration 1.2 Options (1) Cut sheet feeder unit (CSF) Single-bin CSF (2) Pull-tractor assy...
Page 8 (3) Bottom push tractor unit (4) Roll paper stand (Narrow only) (5) Serial I/F - RS-232C...
Page 10: Operation Description
Page: 4 Service Guide ML320/321Turbo Chapter 2 Operation Description 2.1.1 Summary Fig. 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.
Page 12: Microprocessor And The Peripheral Circuit
Page: 5 Service Guide ML320/321Turbo Chapter 2 Operation Description 2.1.2 Microprocessor and the Peripheral Circuit (1) 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.
Page 13 (3) RAM (MSM51C464A-80RS) The RAM is CMOS dynamic RAM with (64K x 4-bit) x 2 configuration, and used as buffers (such as receiving buffer, printing buffer, DLL buffer and working buffer). The following shows examples of the memory access operation.
Page 14 (4) 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.
Page 15 (5) LSI This 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.
Page 17: Initialization
Page: 6 Service Guide ML320/321Turbo Chapter 2 Operation Description 2.1.3 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 LSIs.
Page 19: Parallel Interface Control
When reception is impossible because the buffer is full, the BUSY signal is sent to stop 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 20: Print Control
Page: 8 Service Guide ML320/321Turbo Chapter 2 Operation Description 2.1.5 Print Control Print data is transmitted as parallel data (HEAD1-HEAD9) from the LSI to the print head. The LSI generates the print timing and drive time. Print Compensation Control The print compensation methods are shown below: (a) Voltage compensation (See 2.1.8 "Alarm Circuit."...
Page 21 According to the thickness of the printing medium, the print mode is compensated as shown in the table below 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: Sp/Lf Motor Control
Page: 9 Service Guide ML320/321Turbo Chapter 2 Operation Description 2.1.6 SP/LF Motor Control (1) 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 (øA, øB) of the slit encoder included in the space motor.
Page 23 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. 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 24: Operation Panel
Page: 10 Service Guide ML320/321Turbo Chapter 2 Operation Description 2.1.7 Operation Panel The clock synchronization OPCLK signal of the LSI is used to input the switch data and output the LED data through the operation panel control LSI (IC1: BU5148S). A 2-byte (15 bits + 1 even parity bit) command signal (OPTXD) is transmitted to the LSI(BU5148S) in synchronization with the OPCLK signal.
Page 25 This is because the bit 0 to bit 3 the OPRXD signal are fixed so that the response can be returned before decoding the command. 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 26: Alarm Circuit
Page: 11 Service Guide ML320/321Turbo Chapter 2 Operation Description 2.1.8 Alarm Circuit (1) 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).
Page 27 - When the temperature exceeds 119°C, printing stops. - When temperature gradient is steep, the higher mode is 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 28: Power Supply Circuit
This power supply circuit supplies the +5VDC, +8VDC, +40VDC, 10VAC. The uses of output voltages and signals are described below. 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 29: Mechanical Operation
Page: 13 Service Guide ML320/321Turbo Chapter 2 Operation Description 2.2 Mechanical Operation 2.2.1 Printhead Mechanism and Operation (See Figure 2-2 below). The printhead is a spring charged 9-pin driving head using a permanent magnet. It is attached to the carriage, which moves parallel to the platen. Electrically, this unit is connected to the control circuits through the control board.
Page 30 A thermistor in the printhead prevents burning caused by overheating of the coil during extended continuous bi-directional printing. When the temperature of the coil exceeds a predetermined 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.
Page 32: Spacing Operation (See Figure 2-4.)
Page: 14 Service Guide ML320/321Turbo Chapter 2 Operation Description 2.2.2 Spacing Operation (See Figure 2-4 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)
Page 33 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 34: Head Gap Adjusting (See Figure 2-5.)
Page: 15 Service Guide ML320/321Turbo Chapter 2 Operation Description 2.2.3 Head Gap Adjusting (See Figure 2-5 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.
Page 35 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 36: Ribbon Drive (See Figure 2-6.)
Page: 16 Service Guide ML320/321Turbo Chapter 2 Operation Description 2.2.4 Ribbon Drive (See Figure 2-6 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...
Page 37 Figure 2-6 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: Paper Feed Operation
Page: 17 Service Guide ML320/321Turbo Chapter 2 Operation Description 2.2.5 Paper Feed Operation Paper is fed by turning the platen and the pin tractor, which is driven by the LF pulse motor. The paper feed mechanism consists of the following: (a) Pulse motor with gears (b) Decelerating gear (c) Platen...
Page 39 the drive gear of the bottom tractor feed unit through the idle gear to feed the sheet which set in the bottom tractor feed. At the same time, the switch lever turns on the bottom switch to inform the control board that you are in the continuous sheet mode.
Page 40 (2) Cut-sheet feeder operation (See Figure 2-9.) 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.
Page 41 (4) Pull tractor (option) and push tractor operation (See Figure 2-11) This mechanism supports the standard push tractor and an optional pull tractor. It can perform forward and reverse feed by sending paper either to the push tractor (for rear feed) or to the pull tractor (for bottom feed).
Page 42 (5) Pull tractor mechanism (option) (See Figure 2-12.) Bottom feed of continuous sheets is possible only when the 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.
Page 43 (7) Paper clamp mechanism (See Figure 2-14.) 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. At the same time, the position of the cam relative to the front release gear arm changes, opening or closing the pressure roller.
Page 45: Paper Detection Mechanism (See Figure 2-15.)
Page: 18 Service Guide ML320/321Turbo Chapter 2 Operation Description 2.2.6 Paper Detection Mechanism (See Figure 2-15 below). (1) Cut sheet detection When the sheet is inserted, point A is pushed backward and the paper near end lever B rotates counterclockwise (CCW). At this time, the rear sensor lever rotates counterclockwise (CCW) and pulls out of the rear and top paper end sensor to detect that the sheet is inserted.
Page 46 Printing starts at the top of the sheet, and continues uni-directionally until the top edge of the sheet gets to the inside of the pull-up roller cover. After that, printing continues bi-directionally. Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business...
Page 47 Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)
Page 48: Automatic Sheet Feed
Page: 19 Service Guide ML320/321Turbo Chapter 2 Operation Description 2.2.7 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 sheet paper is used. Operational procedure (1) When using cut sheet paper: 1) Set the change lever to the TOP position.
Page 49 When the LF motor completes its operation and the sheet has not been fed in, an alarm condition results. 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: Paper Park Function (Continuous Sheet Paper)
This operation is required when the paper to be parked is more than 19 inches long. 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: Parts Replacement
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 52: Precautions For Parts Replacement
Page: 22 Service Guide ML320/321Turbo Chapter 3 Parts Replacement 3.1 Precautions for Parts Replacement (1) Remove the AC power cord and the interface cable before disassembling or assembling. (a) Turn off the power switch. Remove the plug of the AC power cord from the outlet. Remove the power cord from the receptacle on the printer.
Page 54: Service Tools
Table 3.1 lists the tools necessary for replacing printed circuit boards and parts of units in the field. 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 55: Disassembly/Reassembly Procedure
Page: 24 Service Guide ML320/321Turbo Chapter 3 Parts Replacement 3.3 Disassembly/Reassembly Procedure This section explains the assembly replacement procedures according to the following disassembly system. Parts Layout How to Change Parts This section explains how to change parts and assemblies appearing in the disassembly diagram below.
Page 57: Printhead
Page: 25 Service Guide ML320/321Turbo Chapter 3 Parts Replacement 3.3.1 Printhead (1) Open the access cover. (2) Pull up and rotate the head clamp 1 to unclamp the printhead 2 as shown in fig. 3.3.1. (3) Disconnect the printhead 2 from PC connector 3 and remove. (4) To install, reverse the removal steps.
Page 59: Ribbon Protector
(6) To install, follow the removal steps in reverse order. Be sure to replace the shim in exactly the same position as it was before disassembly. 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 60: Pull-Up Roller Assy
Note: Remove the sheet guide Assy 4 before installing or removing the pull-up roller Assy 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 61 Page: 28 Service Guide ML320/321Turbo Chapter 3 Parts Replacement 3.3.4 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.
Page 63: Gear Case Assy
Page: 29 Service Guide ML320/321Turbo Chapter 3 Parts Replacement 3.3.5 Gear Case Assy (see 3.3.1 (1) Remove the printhead (2) Remove the shim from the carriage frame. (3) Remove the upper cover (see 3.3.4 (4) Move the carriage Assy to right side, remove two screws 1, then remove the carriage Assy. (5) Disengage claws on the gear Assy (4 places).
Page 65: Pc Connector
(1) Do not touch the space motor 2 or terminals of PC connector 1. Also, take care to avoid dust or foreign matter. (2) After installation, check and adjust the gap between platen and printhead (see 4-1 Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business...
Page 66 Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)
Page 67: Space Motor, Guide Roller Assy
Page: 31 Service Guide ML320/321Turbo Chapter 3 Parts Replacement 3.3.7 Space Motor, Guide Roller Assy (see 3.3.1 (1) Remove the printhead (2) Remove the upper cover (see 3.3.4 (3) Remove the gear case Assy (see 3.3.5 (4) Remove the PC connector (see 3.3.6 (5) Remove screw 2, then the guide roller Assy 3 from the space motor Assy 1.
Page 69: Space Rack
Page: 32 Service Guide ML320/321Turbo Chapter 3 Parts Replacement 3.3.8 Space Rack (see 3.3.4 (1) Remove the upper cover (2) Remove the printhead (see 3.3.1 (3) Remove the shim from the carriage frame. (4) Remove the gear case Assy (see 3.3.5 (5) Remove the space motor Assy (see 3.3.7 (6) Remove the spring 1.
Page 71: Carriage Cable
Page: 33 Service Guide ML320/321Turbo Chapter 3 Parts Replacement 3.3.9 Carriage Cable (see 3.3.4 (1) Remove the upper cover (2) Remove the printhead (see 3.3.1 (3) Remove the shim from the carriage frame. (4) Remove the gear case Assy (see 3.3.5 (5) Remove the space motor Assy (see 3.3.7 (6) Remove the two screws 1, release the driver board 2 and PCB board 9 by lifting clamp 8, and...
Page 73: Backup Roller Holder Assy
Note: Small round hole with metal tip on back of roller holder assy 3 should be facingup 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 74: Platen Assy
(7) Remove the platen Assy 4 from the base frame. (8) To install, follow the removal steps in 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 75: Driver Board (Sddv)
Page: 36 Service Guide ML320/321Turbo Chapter 3 Parts Replacement 3.3.12 Driver Board (SDDV) (see 3.3.4 (1) Remove the upper cover (2) Remove the two screws 1, and release the driver board 2 by lifting clamp 4. (3) Disconnect all cables from driver board 2. (4) To install, follow the removal steps in reverse order.
Page 77: Lf Motor
Page: 37 Service Guide ML320/321Turbo Chapter 3 Parts Replacement 3.3.13 LF Motor (see 3.3.4 (1) Remove the upper cover (2) Remove the printhead (see 3.3.1 (3) Remove the ribbon protector (see 3.3.2 (4) Remove the pull-up roller Assy (see 3.3.3 (5) Remove the platen Assy (see 3.3.11 (6) Remove the driver board...
Page 79: Operation Panel Pcb (Leop)
Page: 38 Service Guide ML320/321Turbo Chapter 3 Parts Replacement 3.3.14 Operation Panel PCB (LEOP) (see 3.3.4 (1) Remove the upper cover (2) Disconnect 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 .
Page 81: Control/Power Supply Board (Sdct)
Page: 39 Service Guide ML320/321Turbo Chapter 3 Parts Replacement 3.3.15 Control/Power Supply Board (SDCT) (see 3.3.4 (1) Remove the upper cover (2) Disconnect the two flexible cables 3 from connector 2 on the Control/Power Supply Board 1. (3) Remove cable 5 from connector 4 on the control/power supply board 1. (4) Remove the two screws 6, and remove the control power supply board 1.
Page 83: Transformer Assy
(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 84: Change Lever And Gears
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 85: Carriage Shaft
Note on installation: After installation, check and adjust the gap between platen and printhead (see 4-1). 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: Paper Pan
(7) Lift up the paper chute assy 1 and remove. (8) To install, reverse 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 87: Rear Tractor Assy
Page: 44 Service Guide ML320/321Turbo Chapter 3 Parts Replacement 3.3.20 Rear Tractor Assy (see 3.3.1 (1) Remove the printhead (see 3.3.2 (2) Remove the ribbon protector (see 3.3.3 (3) Remove the pull-up roller assy (see 3.3.4 (4) Remove the upper cover (5) Remove the reset spring (see 3.3.17 (3) ).
Page 89: Rear Pressure Assy
Page: 45 Service Guide ML320/321Turbo Chapter 3 Parts Replacement 3.3.21 Rear Pressure Assy (see 3.3.4 (1) Remove the upper cover (2) Remove the change lever and gears (see 3.3.17 (3) Remove the paper pan (see 3.3.19 (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.
Page 91: Switch Lever
When installing the switch lever, make sure that the microswitch on the driver board works properly. 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 92: Adjustments
Page: 47 Service Guide ML320/321Turbo Chapter 4 Adjustments 4. ADJUSTMENT (1) Be sure to carry out these adjustments with the printer mechanism installed on the lower cover. (2) Be sure to carry out these adjustment operations on a level and highly rigid work table (flatness: less than 0.039 inch or 1 mm) so as to minimize adjustment error.
Page 93 Adjustment method (1) Gap between the platen and the printhead at the left end and the right end shall be adjusted by rotating the adjust cam. (2) Set the adjust lever at the Range: 1. Press the adjust gear downward (indirection A) to push the adjust gear and the adjust gear out of mesh.
Page 94 Note 3) Move the adjust screw in clockwise direction (in direction B) to measure. 4-1-2 Measure variation of gap when range is changed. Gap =0 .6 9±0.05 at the range 5.
Page 95 Gap between the contact and the monitor. 0.3mm or more Verify the following. Make sure that the gap between the contact and the motor PCB is 0.3 mm or more. At the time of printing test, make sure that the contact touches the motor PCB and it enters reduced speed mode when the adjust lever is set to range 2 and 4.
Page 96 Verify the following. (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 pressure roller at the rear side shall be 3mm.
Page 97 Verify: There shall be slight backlash between gears to allow smooth rotation of gears. (Backlash 0.05 to 0.11 4-5-1 Ribbon feed Verify: Ribbon shall be fed smoothly when the carriage is moved from side to side. 4-5-2 Running load to spacing mechanism 250g or less without a ribbon cartridge Verify: Make sure that the power is turned off at the time of measurement.
Page 99: Periodical Maintenance
Page: 48 Service Guide ML320/321Turbo Chapter 5 Periodical Maintenance 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.
Page 101: Lubrication
Page: 49 Service Guide ML320/321Turbo Chapter 5 Periodical Maintenance 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 if the printer is disassembled, reassembled, cleaned, or if parts have been changed.
Page 102 (5) Lubrication point 1. Ribbon feed gear Assy. 2. Space Rack...
Page 103 3. Platen Assy. 4. Tractor driving mechanism...
Page 104 5. Tractor drive shaft 6. Pressure roller...
Page 105 7. Pull up roller Assy.
Page 106 8. Main chassis Assy. 9. Carriage Assy.
Page 108: Troubleshooting
(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://bpx.okidata.com)
Page 109: Troubleshooting Table
Page: 51 Service Guide ML320/321Turbo Chapter 6 Troubleshooting 6.2 Troubleshooting Table 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 110: Lamp Display
Page: 52 Service Guide ML320/321Turbo Chapter 6 Troubleshooting 6.3 Lamp Display (1) Printer mode display (2) Fault alarm display When the printer detects any of the various alarm states, the information is displayed as shown below on the operation panel. The alarm is specified by lamp combination of PRINT QUALITY and CHARACTER PITCH.
Page 111 PITCH. (See Table 6.3 below for details.) (3) Fatal Alarm Alarm Alarm Alar Remarks Troubleshooting Category Display Main Control MPU internal Read/write Replace Control/Power Alarm RAM alarm error Supply Board Main Control Program Check sum Replace ROM or Alarm ROM alarm error control/Power Supply Board...
Page 112 Alarm Alarm Alar Remarks Troubleshooting Category Display Spacing Spacing PROP, Space IPT is * Replace space motor. Alarm alarm not occurred * Replace P.H. cable. within in * Replace Control/Power specified Supply Board. timing. * Check the mechanisms if load is too much. Spacing Print Head PROP,...
Page 114: Connection Circuit Check For Printhead And Sp/Lf Motor
Page: 53 Service Guide ML320/321Turbo Chapter 6 Troubleshooting 6.4 Connection Circuit Check for Printhead and SP/LF Motor (1) Printhead (2) Line Feed Motor Resistance of each coil should be about 7.6 Ohms.
Page 115 (3) Space Motor Resistance of each coil should be about 5 Ohms. 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: Troubleshooting Flow Chart
Page: 54 Service Guide ML320/321Turbo Chapter 6 Troubleshooting 6.5 Troubleshooting Flow Chart...
Page 126: A Centronics Parallel Interface
(1) Circuit board SDCT (Control/Power Supply) (2) Circuit board SDDV (Driver) (3) Circuit board LEOP-3 (Operation Panel) 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 127: B Parts Listing
Figure 11-2 Printer General Assy Figure 11-3 Printer Unit Figure 11-4 Carriage Assy Figure 11-5 Option Spare Parts 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 128 Chapter B Parts Listing Figure 11-1 Upper Cover Assy Part No. Description Remarks ODA P/N Reqd 1PP4128-1186P6 Upper cover (N) For ML320 Turbo For INT 1PP4128-1186P4 Upper cover (N) For ML320 Turbo For OEL 1PP4128-1186P2 Upper cover (N) For ML320 Turbo...
Page 129 (W) 1PP4128-1188P1 Acoustic cover For ML320 Turbo 53076901 1PP4128-1233P1 Acoustic cover For ML321 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)
Page 130 Page: 58 Service Guide ML320/321Turbo Chapter B Parts Listing Figure 11-2 Printer General Assy Part No. Description Q'ty Q'ty Remar ODA P/N...
Page 131 (ML320 Turbo 230/240V) 4YB4049-7104P2 Transformer assy (ML321 Turbo 230/240V) 3PB4050-3429P2 PCB plate ODA, OEL 230V 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 132 Page: 59 Service Guide ML320/321Turbo Chapter B Parts Listing Figure 11-3 Printer Unit...
Page 133 Part No. Description Q'ty Q'ty Remarks ODA P/N Required 3PA4044-5002G2 Main chassis assy (N) For ML320 Turbo 53348801 53348801 Main chassis assy For ML321 Turbo 53348901 3PP4044-5012P1 Bottom paper end 50809201 lever 4PP4044-5019P1 Pressure spring (F) For ML320 Turbo 50931301...
Page 134 For ML321 Turbo 3PP4044-5046P1 Tractor sheet guide For ML321 Turbo 51022901 4PB4044-5095P1 FG plate (A) 51022401 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 135 Page: 60 Service Guide ML320/321Turbo Chapter B Parts Listing Figure 11-4 Carriage Assy Part No. Description Q'ty Q'ty Remarks ODA# Req'd 4PP4044-5061G1 Carriage frame set 53349801...
Page 136 Ribbon protector 53077101 4PP4025-3397P1 Back up roller holder 50925001 spring 4PP4044-5066P1 Guide roller spring 50931801 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 137 Page: 61 Service Guide ML320/321Turbo Chapter B Parts Listing Figure 11-5 Option Spare Parts 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 138: C Software Diagnostics And Adjustments
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 139: Operation Description
Page: 63 Service Guide ML320/321Turbo Chapter C Software Diagnostics and Adjustments 2. OPERATION DESCRIPTION 2.1 Element 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.
Page 141: Operation At Power On
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.okidata.com)
Page 142: Rs-232C 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 (BPX) for any updates to this material. (http://bpx.okidata.com)
Page 143: Communication Procedure Flowchart
Page: 66 Service Guide ML320/321Turbo Chapter C Software Diagnostics and Adjustments 2.3 Communication Procedure Flowchart...
Page 146: Troubleshooting Flowchart
Page: 67 Service Guide ML320/321Turbo Chapter C Software Diagnostics and Adjustments 3. TROUBLESHOOTING FLOWCHART 3.1 Before Repairing a Fault Before servicing the printer, ask the customer under what circumstances the trouble occurred and record the response. Before you start troubleshooting, operate the printer under the same conditions as that at the time of the problem to see if the same trouble occurs again.
Page 148 2 In receiving by serial interface, printing data is omitted or printing operation is not performed.
Page 150: Local Test
Page: 68 Service Guide ML320/321Turbo Chapter C Software Diagnostics and Adjustments 3.3 Local Test 3.3.1 Circuit test mode 3.3.1.1 Setting (1) Diagnostic test (set by menu) (2) Test connector Connect the test connector shown in Figure C-3-6 to the interface connector CN1 on the LXH1 board 3.3.1.2 Function After the settings outlined in Section 3.3.1.1 are completed and power is turned on, the serial interface checks the message buffer memory and interface driver/receiver circuit.
Page 151 (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 material. (http://bpx.okidata.com)

This manual is also suitable for:

Ml321 turbo

OKIDATA ML320 Turbo Service Manual

1 Configuration

2 Operation Description

3 Parts Replacement

4 Adjustments

5 Periodical Maintenance

6 Troubleshooting

A Centronics Parallel Interface

B Parts Listing

C Software Diagnostics and Adjustments

Quick Links

Troubleshooting

Related Manuals for OKIDATA ML320 Turbo

Summary of Contents for OKIDATA ML320 Turbo

This manual is also suitable for:

Table of Contents