Printronix P300 User manual

P300 / P600 Line Printers
Maintenance Manual
R

P300 / P600 Line Printer
Maintenance Manual
R
P/N 140294–001, Rev C

US and CANADA Radio Interference Note
Note: This device complies with Part 15 of the FCC Rules. Operation is subject to the following two
conditions: (1) this device may not cause harmful interference, and (2) this device must accept any
interference received, including interference that may cause undesired operation.
Properly shielded and grounded cables and connectors must be used in order to meet FCC emission limits.
The manufacturer is not responsible for any radio or television interference caused by using other than
recommended cables and connectors or by unauthorized changes or modifications to this equipment.
Unauthorized changes or modifications could void the user’s authority to operate the equipment.
The input/output (I/O) cable must be shielded for the printer to comply with FCC rules and regulations Part
15 governing the radiation limits for Class “A”equipment.
This Class A digital apparatus meets all requirements of the Canadian Interference–Causing Equipment
Regulations.
Cet appareil numérique de la classe A respecte toutes les exigences du Règlement sur le matériel brouilleur
du Canada.
WARNING
This is a Class A product. In a domestic environment this product may cause radio interference in which
case the user may be required to take adequate measures.
Printronix, Inc. makes no representations or warranties of any kind regarding this material, including, but not
limited to, implied warranties of merchantability and fitness for a particular purpose. Printronix, Inc. shall not
be held responsible for errors contained herein or any omissions from this material or for any damages,
whether direct, indirect, incidental or consequential, in connection with the furnishing, distribution,
performance or use of this material. The information in this manual is subject to change without notice.
This document contains proprietary information protected by copyright. No part of this document may be
reproduced, copied, translated or incorporated in any other material in any form or by any means, whether
manual, graphic, electronic, mechanical or otherwise, without the prior written consent of Printronix, Inc.
All rights reserved. Revision C. November 1996.
Trademark Acknowledgements
P300/P600 Maintenance Manual, 140294–001, Revision B, January 1996.

17500 Cartwright Road, P.O. Box 19559
Irvine, California 92713
Telephone [phone] FAX [phone]
Technical Support (714) 221–2686
COPYRIGHT 1988, 1991, 1996, PRINTRONIX, INC.

iP300/P600
ABOUT THIS MANUAL
What This Maintenance Manual Contains
This manual contains information for servicing and repairing P300 and P600 printers, in either pedestal or
floor cabinet (XQ) configurations, at the field maintenance level:
Chapter
1: Maintenance Overview — Briefly describes features, options, physical configurations,
and controls and indicators of P300 and P600 printers.
Chapter 2: Principles of Operation — Describes the operation of the printer through the use of
block
diagrams and associated text .
Chapter 3: Pr eventive Maintenance — Lists procedures for maintaining normal printer operation.
Chapter 4: Troubleshooting — Presents fault isolation procedures for determining the source of
common malfunctions.
Chapter 5: Corrective Maintenance — Contains procedures for printer adjustments, alignments,
and replacement of hardware.
Appendices — Appendix A lists PROM kit applications for P300 and P600 printers. Appendix B is a
PCBA jumper location guide. Appendix C lists part numbers for components replaceable at the
field maintenance level, cross–referenced to the illustrations in Chapter 5.
What This Manual Does Not Contain
Operational information covered in the User’ s Reference Manual is not repeated in this manual.
WARNING, CAUTION, IMPORTANT, and NOTE
Always read and comply with special information. Special information is highlighted under headings that
alert you to the nature of the information:
–WARNING –
AWARNING tells you of conditions that could harm you.
–CAUTION –
ACAUTION tells you of conditions that could damage the printer or
related equipment.
–IMPORTANT –
IMPORTANT gives you information vital to proper operation of the
printer.
NOTE:
Pr ovides information affecting printer operation consider ed impor -
tant
enough to emphasize.

P300/P600ii

iP300/P600
Table of Contents
Paragraph Title Page
CHAPTER 1. MAINTENANCE OVER VIEW
1–1 Introduction 1–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1–2 Printer Description 1–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1–3 Specifications 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1–4 Operation 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CHAPTER 2. PRINCIPLES OF OPERATION
2–1 Scope 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–2
Basic Functions and Circuit Locations 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–3 Principle States of Operation 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–4 Buffer Load State 2–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–5 Print State 2–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–6 Paper Feed State 2–35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–7 Ribbon Transport 2–56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–8 Power Supply 2–58. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CHAPTER 3. PREVENTIVE MAINTENANCE
3–1 General 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–2
Preventive Maintenance Checks and Service 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–3 Inspection 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–4 Cleaning 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–5 Lubrication 3–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CHAPTER 4. TROUBLESHOOTING
4–1 General 4–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–2
Common Causes Of Malfunctions 4–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–3 Testing 4–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–4 Fault Isolation 4–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–5 Performance Tests 4–71. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

P300/P600ii
Table of Contents
Paragraph Title Page
CHAPTER 5. CORRECTIVE MAINTENANCE
Section I. GENERAL
5–1 Introduction 5–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–2 Tools, Test Equipment, and Supplies 5–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Section II. ALIGNMENTS AND ADJUSTMENTS
5–3 Ribbon Hub Height Adjustment 5–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–4 Ribbon T
racking Check and Adjustment 5–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–5 Shuttle Spring Force Adjustment 5–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–6 Setting Shuttle and Counterweight Preload 5–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–7 Hammer Spring Retensioning 5–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–8 Hammer Tip Alignment 5–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–9 Hammer Tip Height (Protrusion) Adjustment 5–16. . . . . . . . . . . . . . . . . . . . . . . . . . .
5–10 Platen Gap 5–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–11
Magnetic Pickup Gap 5–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–12
Magnetic Pickup Phasing Adjustment 5–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–13 Adapting Shuttle Motor to Line Frequency 5–23. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–14 Shuttle Belt 5–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–15 Paper Feed Belt 5–26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–16 Paper Motion Sensor 5–28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–17 Paper Out Detectors 5–30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Section III. REPLACEMENT
5–18 Printer Cover 5–32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–19 Control Panel 5–36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–20 Ribbon Drive 5–38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–21
Ribbon Control PCBA 5–42. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–22 Ribbon Drive Motor 5–44. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–23 Ribbon Drive Blower 5–46. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–24
Shuttle Assembly 5–50. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–25 Hammer Spring 5–56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–26 Hammer Coil 5–58. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–27
Counterweight Assembly 5–62. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–28
Flywheel Assembly 5–65. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

iiiP300/P600
Table of Contents
Paragraph Title Page
CHAPTER 5. CORRECTIVE MAINTENANCE
Section III. REPLACEMENT – continued
5–29 Cam W ick 5–67. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–30 Magnetic Pickup 5–67. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–31 Shuttle Motor 5–70. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–32 Shuttle Belt 5–72. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–33 Paper Ironer 5–74. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–34 Paper Feed Belt 5–76. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–35 Paper Feed Motor 5–78. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–36 Tractor 5–80. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–37 Paper Motion Sensor 5–82. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–38
Paper Out Mechanical Switch 5–84. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–39 Paper Out Optical Sensor 5–86. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–40 DC Power Supply Fuse 5–88. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–41 Power Supply PCBA 5–90. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–42 Power Supply 5–92. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–43
Rear Fan 5–94. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–44 Logic PCBA 5–98. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–45 Hammer Driver PCBA 5–100. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–46
Hammer Bank Cable Harness 5–102. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
APPENDICES
Appendix A: Prom Kit Applications A–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix B: PCBA Jumper Location Guide B–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix C: Parts List C–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

P300/P600iv
List of Illustrations
Figure Title Page
1–1
Printer: Pedestal Model and XQ Cabinet Model 1–3. . . . . . . . . . . . . . . . . . . . . . . . .
1–2 External Controls and Indicators 1–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1–3 Internal Controls and Indicators 1–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1–4
Controls and Indicators for Options on Pedestal Models 1–8. . . . . . . . . . . . . . . . . . .
2–1 Printer System Block Diagram 2–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–2 Buffer Load State Block Diagram 2–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–3 Interface Block Diagram 2–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–4 Interface Timing 2–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–5 Dot Selection Block Diagram 2–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–6 Defining the Dot Matrix 2–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–7T
ypical Characters (Data Processing Mode) 2–13. . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–8 Elongated Character With and W
ithout Descenders 2–14. . . . . . . . . . . . . . . . . . . . . .
2–9 Dot Column and Character Column Timing for One Shuttle Cycle 2–16. . . . . . . . . .
2–10 Dot Column and Character Column Counter Block Diagram 2–17. . . . . . . . . . . . . . .
2–11 Plotting the Six Bit Code 2–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–12 Hammer Driver Block Diagram 2–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–13 Hammer Driver Circuit Timing 2–23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–14 Safety Circuits 2–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–15
Hammer Reset T imer 2–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–16 Dot Row Timing vs T iming Disk and Cam Position 2–27. . . . . . . . . . . . . . . . . . . . . .
2–17 Operation of MPU Circuit 2–28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–18 Hammer and Shuttle Arrangement 2–29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–19 Print Hammer Action 2–30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–20 Standard Character Formation 2–31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–21 P600 Phase Fire Operation 2–33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–22
Hammer Bank Shuttle Components 2–34. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–23 Paper Feed Logic Block Diagram 2–37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–24 Line Feed Operation Velocity Profile 2–39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–25 Timing Sequence for Printing One Character Line 2–40. . . . . . . . . . . . . . . . . . . . . . .
2–26 Top–of–Form Counter Block Diagram 2–42. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–27 Top–of–Form Slewing Velocity Profile 2–43. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–28 Paper Feed to Top–of–Form Timing 2–44. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–29 EVFU Loading Block Diagram 2–46. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–30 EVFU Loading Sequence Timing Diagram 2–46. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–31 EVFU Channel Seek Block Diagram 2–48. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–32 EVFU Channel Seek Velocity Profile 2–49. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–33 EVFU in Binary Count Mode 2–50. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–34 Paper T
ransport Components 2–52. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–35 Paper Motion Detector Diagram 2–54. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–36 Paper Feed Control Circuits Block Diagram 2–55. . . . . . . . . . . . . . . . . . . . . . . . . . . .

vP300/P600
List of Illustrations
Figure Title Page
2–37 Ribbon Drive Block Diagram 2–56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–38 Ribbon Control PCBA Simplified Schematic 2–57. . . . . . . . . . . . . . . . . . . . . . . . . . .
2–39 Power Supply Assembly 2–59. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–40
+36 V and +70 V Supplies 2–63. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–41
Reference V oltage Circuit 2–64. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–42
+5 V and MOS Supplies 2–65. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–43 Relay Switching Details 2–67. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–44 Motor Relay Trigger Circuit 2–68. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–1 Cleaning Interior of Cabinet 3–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–2
Cleaning Hammer Bank Assembly–Ribbon Drive to Service Position 3–7. . . . . . . .
3–3 Cleaning Hammer Bank Assembly–Hammer Bank to Service Position 3–8. . . . . . .
3–4 Lubrication, Counterweight and Cam Wick 3–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–5 Lubrication, Self–Aligning Cam Followers, P600 Only 3–13. . . . . . . . . . . . . . . . . . .
3–6 Lubrication, Antirotation Arm, P300 Only 3–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–1
Confidence Check 4–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–2 New Printer Does Not Operate 4–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–3 POWER Indicator Not Illuminated 4–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–4 CHECK Indicator Stays On 4–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–5 ON LINE Indicator Not Illuminated 4–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–6 Shuttle Does Not Accelerate to Speed When ON LINE Switch
is Pressed 4–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–7
Ribbon Does Not Advance 4–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–8 Ribbon Folds Over 4–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–9 Ribbon Not Feeding Smoothly 4–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–10 End of Ribbon Not Detected 4–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–11 Not Printing 4–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–12
Missing Characters 4–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–13
Missing Characters, Example of 4–28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–14 Missing Dots 4–29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–15
Missing Dots, Example of 4–35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–16 Light and/or Smeared Characters 4–36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–17 Light and/or Smeared Characters, Example of 4–38. . . . . . . . . . . . . . . . . . . . . . . . . .
4–18
Misplaced Dots 4–39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–19 Print Too Light or Dark 4–43. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–20 Print Too Light or Dark, Example of 4–45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–21
Horizontal Misalignment 4–46. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–22 Horizontal Misalignment, Example of 4–47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–23 V
ertical Misalignment 4–48. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–24 Vertical Misalignment Character Position, Example of 4–52. . . . . . . . . . . . . . . . . . . .
4–25 Vertically Deformed Characters, Example of 4–53. . . . . . . . . . . . . . . . . . . . . . . . . . .

P300/P600vi
List of Illustrations
Figure Title Page
4–26 Vertical Compression of Print 4–54. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–27 Garbled Letters and/or Wrong Font 4–55. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–28 No Paper Feed 4–57. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–29 Paper Feeds Erratically 4–61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–30 Paper Drags 4–66. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–31 Top–of–Form Does Not Operate 4–69. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–32 Shift Recycle Test –Sliding Pattern 4–71. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–33 Plot Pattern Test 4–72. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–34 MPU Phasing T
est –All Hs 4–73. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–35 Row Increment T
est –Uppercase Characters 4–74. . . . . . . . . . . . . . . . . . . . . . . . . . .
4–36 Underline/Vertical Hammer Alignment Test 4–75. . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–1
Ribbon Hub Height Adjustment 5–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–2 Ribbon T
racking Check and Adjustment 5–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–3 Shuttle Spring Force Adjustment 5–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–4 Setting Shuttle and Counterweight Preload 5–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–5 Hammer Spring Retensioning 5–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–6 Hammer Tip Alignment 5–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–7 Hammer Tip Height Adjustment 5–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–8
Platen Gap Adjustment 5–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–9
Magnetic Pickup Gap and Phasing Adjustment 5–21. . . . . . . . . . . . . . . . . . . . . . . . . .
5–10 Shuttle Belt T ension Check and Adjustment 5–25. . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–11 Paper Feed Belt T
ension Check and Adjustment 5–27. . . . . . . . . . . . . . . . . . . . . . . . .
5–12 Paper Motion Sensor Check and Adjustment 5–29. . . . . . . . . . . . . . . . . . . . . . . . . . .
5–13 Paper Out Detector Adjustment 5–31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–14
Cover Removal/Installation, Pedestal Models 5–34. . . . . . . . . . . . . . . . . . . . . . . . . . .
5–15 Cover Removal/Installation, Floor Cabinet (XQ) Models 5–35. . . . . . . . . . . . . . . . . .
5–16 Control Panel Removal/Installation 5–37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–17
Ribbon Drive Removal/Installation, Pedestal Models 5–40. . . . . . . . . . . . . . . . . . . . .
5–18 Ribbon Drive Removal/Installation, Floor Cabinet (XQ) Models 5–41. . . . . . . . . . . .
5–19
Ribbon Control PCBA Removal/Installation, Pedestal Models 5–43. . . . . . . . . . . . . .
5–20 Ribbon Drive Motor Removal/Installation 5–45. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–21
Ribbon Drive Blower Removal/Installation, Pedestal Models 5–48. . . . . . . . . . . . . .
5–22
Ribbon Drive Blower Removal/Installation, XQ Models 5–49. . . . . . . . . . . . . . . . . .
5–23
Shuttle Assembly Removal/Installation 5–51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–24 Hammer Spring Removal/Installation 5–57. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–25 Hammer Coil Removal/Installation 5–60. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–26
Counterweight Assembly Removal/Installation 5–63. . . . . . . . . . . . . . . . . . . . . . . . . .
5–27 Flywheel Assembly Removal/Installation 5–66. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–28
Cam W ick Removal/Installation 5–68. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–29 Magnetic Pickup Removal/Installation 5–69. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–30 Shuttle Motor Removal/Installation 5–71. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–31 Shuttle Belt Removal/Installation 5–73. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–32 Paper Ironer Removal/Installation 5–75. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

viiP300/P600
List of Illustrations
Figure Title Page
5–33 Paper Feed Belt Removal/Installation 5–77. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–34 Paper Feed Motor Removal/Installation 5–79. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–35 Tractor Removal/Installation 5–81. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–36 Paper Motion Sensor Removal/Installation 5–83. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–37
Paper Out Mechanical Switch Removal/Installation 5–85. . . . . . . . . . . . . . . . . . . . . .
5–38 Paper Out Optical Sensor Removal/Installation 5–87. . . . . . . . . . . . . . . . . . . . . . . . .
5–39
DC Power Supply Fuses Removal/Installation 5–89. . . . . . . . . . . . . . . . . . . . . . . . . .
5–40 Power Supply PCBA Removal/Installation 5–91. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–41 Power Supply Removal/Installation 5–93. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–42
Rear Fan Removal/Installation, Pedestal Models 5–95. . . . . . . . . . . . . . . . . . . . . . . .
5–43 Rear Fan Removal/Installation, Floor Cabinet (XQ) Models 5–96. . . . . . . . . . . . . . .
5–44
Logic PCBA Removal/Installation 5–99. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–45 Hammer Driver PCBA Removal/Installation 5–101. . . . . . . . . . . . . . . . . . . . . . . . . . .
5–46
Hammer Bank Cable Harness Removal/Installation 5–103. . . . . . . . . . . . . . . . . . . . . .
List of Tables
Table Title Page
1–1 External Controls and Indicators 1–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1–2 Internal Controls and Indicators 1–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1–3
Controls and Indicators for Options on Pedestal Models 1–8. . . . . . . . . . . . . . . . . . .
2–1 Location of Functional Elements on PCBAs 2–3. . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–2 Interface Signals 2–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–1
Preventive Maintenance Checks and Service 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–2
Physical Inspection 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–1 Malfunction Symptom Index 4–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5–1 Tools, Test Equipment, and Supplies 5–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

P300/P600viii

1–1P300/P600 Maintenance Overview
CHAPTER 1
MAINTENANCE OVERVIEW
1–1. Introduction
This manual contains information for servicing and repairing Printronix P300 or P600 printers, in both
pedestal
and floor cabinet (XQ) configurations, at the field maintenance level. Print speed is the principal
dif ference between P300 and P600 printers. Pedestal and XQ models of a given type dif fer mainly in type
of equipment housing and control panel layout; functionally, they are nearly identical.
1–2. Printer Description (Figure 1–1)
a. General
The Printronix P–Series Printer is a rugged, reliable, multi–function dot matrix line printer . In addition to
basic printing functions, the P–Series printer can produce high speed draft print and dynamic character
generation (character attributes) for wider application compatibility.
b. Standard Features
1. Quiet Operation
2.
Plot Mode
3. Double Height Characters
4. Underlined Characters
5. 14 Channel Electronic Vertical Format Unit (EVFU)
6. Test Pattern Printout
7. Compressed Print (standard on XQ models, optional for pedestal models)
8. High Speed Draft Mode (standard on XQ models, optional for pedestal models)
9. Runs either parallel Centronics or parallel Dataproducts interface
c. Optional Features
1. Alternate Character Sets 5. RS–232C, PI–5225, PI–3287 interfaces
2.
Compressed Print * 6. Forms Length Selector
3. Multi–Mode Print 7. High Speed Draft Mode *
4. Intelligent Graphics Processor
* Standard on XQ models

P300/P600 Maintenance Overview1–2
1–3. Specifications
Detailed specifications for each model printer are listed in the User ’ s Reference Manual that comes with
the printer.
1–4. Operation
a. Operating Procedures
For detailed operating procedures, refer to the User’ s Reference Manual.
b. Controls and Indicators
Controls and indicators are printed in this manual as they appear on the printer —with all capital letters.
(For example: “The POWER switch has two settings —ON and OFF .”) Controls and indicators without
labeled names are assigned functional names that are printed with the first letter of each word capitalized.
(For example: “Raise the Forms Thickness Adjustment Lever to the open position.”)
1. External Controls and Indicators are illustrated in Figure 1–2 and described in T able 1–1.
2. Internal Controls and Indicators are illustrated in Figure 1–3 and described in T able 1–2.
3. Controls and Indicators for printer options are illustrated in Figure 1–4 and described in Table
1–3.

1–3P300/P600 Maintenance Overview
Figure 1–1. Printer: Pedestal Model and XQ Cabinet Model

P300/P600 Maintenance Overview1–4
Table 1–1. External Contr ols and Indicators
KEY
(FIG 1–2)
1
2
CONTROL or
ON/POWER/OFF
1
POWER
FUNCTION
Sets AC power on or off. On XQ models, combined
Indicates power is applied to printer. Non–functional
INDICATOR
INDICATOR
3
4
5
6
7
CHECK
Switch/Indicator
8LPI (pedestal)
Switch/Indicator
PAPER ADVANCE
Switch
TOP OF
FORM
Switch/Indicator
ON LINE
Switch/Indicator
Indicator lights when: platen is open. There is no
paper in printer. Paper doesn’t move during print
ing. Power is interrupted or low.
Switch clears only paper motion fault.
Indicator extinguishes automatically
when other faults are cleared. Performs SELF TEST
On pedestal model, illuminates when 8LPI or
Switch selects line spacing unless overridden by host
computer.
Advances paper as long as it is pressed. Non–func–
Advances paper to top of next form or to channel 1
if EVFU is loaded. Operates only when printer is
offline.
Illuminates on pedestal models when EVFU is loaded
or forms length selector option is installed.
Illuminates when printer is online. Press to select
offline.
switch is available as a spare.
tional lamp is available as a spare. Performs SELF
with circuit breaker and located at right rear bottom
of cabinet.
0
6LPI (cabinet)
alternate is selected. Extinguishes when 6LPI is
selected. On cabinet models, illuminates when 6LPI
is selected and extinguishes when alternate is selected.
4a ALTERNATE
(XQ models only)
Illuminates when line spacing other than 6LPI is
selected. Extinguishes when 6LPI is selected.
PRINT MODE
SELECT
8 Switches select one of three possible print modes:
Switches/Indicators Normal (DP), Compressed, or Draft. Indicators illuminate when switch or host computer control code
selects one of these modes.
OPERATOR
CHECKS
Switches/Indicators
9 CHECK indicator same as number 3 above. RESET
clears and resets printer after a fault is cleared.
Press PRINT TEST then ON LINE to activate all Es
print test. Printer must be on line to perform print
tests.
Indicator
Illuminates when an EVFU form definition program
is loaded into printer memory.
EVFU LOADED10 Indicator
Floor Cabinet (XQ) Models only:
when used with P APER ADV ANCE switch.
TEST when used with CHECK switch.

1–5P300/P600 Maintenance Overview
Figure 1–2. External Contr ols and Indicators

P300/P600 Maintenance Overview1–6
Table 1–2. Internal Contr ols and Indicators
KEY
(FIG 1–3) CONTROL
or
FUNCTION
INDICATOR
1
2
3
4
5
6
7
Forms Thickness
Adjustment Lever
Forms Thickness
Scale and Pointer
Tractors
Tractor Locks
Horizontal
Adjustment
Knob
Vertical Position
Knob
Vertical Position
Disk
Sets platen for different thickness forms or paper.
Opened (raised) fully for loading paper.
Indicates relative thickness of forms or paper.
Used to set left mar gin and paper width. Left
tractor moves about one inch. Right tractor moves
full range. Tractors may be either plastic or metal.*
Lock tractors in position.
Allows fine positioning of left print mar
gin. Moves
paper slightly to left or right.
Provides reference for setting top of form or first
line to be printed.
Normally set at 1 or higher, not fully closed.
Rotate to move paper vertically.
Best set while printing; set to widest possible opening
before print dropout occurs.
Plastic tractors must be aligned by lining* NOTE:
up the marks on the sides of each upper
pulley.