AstroNova QuickLabel QL-900 User manual

Confidential, Not for Redistribution
QL-900 Service Guide
Part Number 22834722-EN-E
Revision 1.0
11/2023
AstroNova, Inc.®
600 East Greenwich Ave., West Warwick, RI 02893
Tel: [phone] Fax: [phone]
[email protected]
www.AstroNovaProductID.com

Confidential, Not for Redistribution
Copyright © 2023 AstroNova ®, Inc.
This manual is copyrighted with all rights reserved. No part of this manual may be reproduced,
transmitted, transcribed, stored in a retrieval system, or translated into any language in any form
by any means without written permission of AstroNova.
Trademarks
QL-900® is a registered trademark of AstroNova, Inc.

Contents
QL-900 Service Guide 4
Confidential, Not for Redistribution
Contents
Chapter 1: Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Intended Audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
General Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Safety When Working with Electricity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Chapter 2: Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Power Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Interface Communication Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Feeding Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Service Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Printhead. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Printing Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Errors and Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Printer Alert Window Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Toolbox System Status Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Software Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Jams in the Printer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Misfeeds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
System Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Advanced Service Menus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Chapter 3: Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Drive Motor Belt Tension Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Feed Roller Belt Tension Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Printhead Lift Motor Drive Belt Tension Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Printhead Lift Assembly Belts Tension Adjustment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Service Station Motor Drive Belt Tension Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Service Station Positioning Belts Tension Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Testing Belt Tension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Contents
QL-900 Service Guide 5
Confidential, Not for Redistribution
Chapter 4: Disassembly and Assembly Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Printer Basic Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Service Disassembly Warnings and Cautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Printer Covers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Operator Side Covers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Non-Operator Side Covers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Top Cover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Ink Tank Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Exit Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Major Components under Non-Operator Side Covers . . . . . . . . . . . . . . . . . . . . . . . 40
Major Components under Exit End Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
General Disassembly and Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Replace 24V DC Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Replace Side Fan Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Replace Side Fan Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Replace Interface PC Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Replace 5V DC Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Adjust 5V DC Power Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Replace Fast Internet Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Replace Top Cover Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Replace Peristaltic Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Replace Printhead Home Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Replace Main PC Board (MPCA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Replace Drive Motor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Replace DPCA Boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Replace Exit Media Guide Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Replace Exit Support and/or Exit Vent Fan Cover . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Replace Exit Vent Fan Assemblies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Replace Cutter Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Replace Ink Door Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Replace Encoder Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Replace Ink Tank Latches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Replace Clamshell Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Remove Ink Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Ink Station Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Replace Buffer Boxes (3 per Printer) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Replace QA Chip Assembly (3 per Printer) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Replace Ink Tank Level PCA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Replace Peristaltic Waste Pump Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Replace Dual Pinch Valve Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Clean Dual Pinch Valve Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Replace Dual Pinch Valve Sensor PC Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Replace Top Forwarding Wheels Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Replace Top Forwarding Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Replace Media Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Replace Center Plate Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Replace Media LED Array and Black Mark Sensor . . . . . . . . . . . . . . . . . . . . . . . . . 69
Replace Exit Media Guide Bottom Plate Assembly . . . . . . . . . . . . . . . . . . . . . . . . . 70
Replace Exit Media Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Remove Exit Media Guide Top Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Replace Exit Star Wheel Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Replace Feed Roller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Replace Transport Rollers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

Contents
QL-900 Service Guide 6
Confidential, Not for Redistribution
Clamshell Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Replace Touchscreen Interface PC Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Replace Touchscreen Micro SD Card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Replace Touchscreen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Remove Adjustable Sensor Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Remove Latch Release Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Remove Printhead Lift Motor Assembly and/or Drive Belt . . . . . . . . . . . . . . . . . . . . 80
Remove Printhead Lift Motor Assembly Large Pulley . . . . . . . . . . . . . . . . . . . . . . . 81
Remove Service Station Sled Motor Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Remove Service Station Sled Motor Drive Belt . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Remove Printhead Lifter Drive Shaft Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Remove Printhead Lifter Belts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Remove Printhead Nest Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Remove Printhead Locator Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Remove Pen Driver Printed Circuit Assembly (PCA) . . . . . . . . . . . . . . . . . . . . . . . . 91
Replace Ink Revolvers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Replace Ink Revolver Gaskets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Replace Printhead Lever Latch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Replace Printhead Lever Latch Solenoid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Inspect the Service Station. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Service Station Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Remove Capping Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Remove Wiper Roller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Remove Wiper Roller Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
Remove Wiper Roller Assembly Springs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
Remove Service Station Base Plate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Remove Service Station Sled. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Remove Service Station Positioning Belts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Remove Service Station Home Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Remove Clamshell Media Guide Assembly (Base Plate w/Transport Wheels) . . . 114
U1C-L Unwinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Remove Top Cover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Rear Cover Access Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Front Panel Cover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Main Drive Belt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Main Drive Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Printed Circuit Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Large Gear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Potentiometer Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Recalibrate Unwinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
W1C-L Winder. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Remove Top Cover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Rear Cover Access Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Front Panel Cover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Main Drive Belt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Main Drive Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Printed Circuit Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
Large Gear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Potentiometer Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Recalibrate Winder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

Contents
QL-900 Service Guide 7
Confidential, Not for Redistribution
Chapter 5: Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
Maintenance Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Inspect/Clean Service Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Inspect Service Station. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Clean Service Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Clean Exit Media Star Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
Clean Cutter Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Clean Pen Driver Printed Circuit Board Contacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Appendix A: Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Appendix B: Ink Flow Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Appendix C: Printer Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
Print Engine Main Printed Circuit Assembly (MPCA) . . . . . . . . . . . . . . . . . . . . . . . . . . 143
Printer Interface PC Board Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Print Engine DPCA-1 and DPCA-2 Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Printer Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

Introduction
QL-900 Service Guide 8
Confidential, Not for Redistribution
Chapter 1: Introduction
Intended Audience
This service guide is intended for use by qualified service and maintenance personnel. For
operation and configuration information, refer to the QL-900 User Guide. This service guide
assumes that you have read the QL-900 User Guide and that you have it available for reference.
Note: This service guide is for use by authorized service and maintenance personnel. Do not
distribute it to others.
General Safety Precautions
Workplace and Work Methods
• Keep the area around the device clean during and after maintenance.
• Work in a safety-conscious manner.
• Store dismantled device parts in a safe place while maintenance is being performed.
• Ensure tools do not become trip hazards.
Clothing
Warning: Moving parts can draw in clothing and lead to injuries.
• If possible, do not wear clothing which could be caught by moving device parts.
• Button or roll up shirt or jacket sleeves.
• Tie or pin up long hair.
• Tuck the ends of scarves, ties and shawls into your clothing or secure them with non-
conductive clips.
Warning: Risk of death from increased flow of current via metal parts which come into contact with
the device.
• Do not wear clothing with metal parts.
• Do not wear jewelry.
• Do not wear glasses with a metal frame.

Introduction
QL-900 Service Guide 9
Confidential, Not for Redistribution
Protective Clothing
If a possible danger to your eyes is present, wear protective goggles, especially in the following
cases:
• when knocking in or knocking out pins and similar parts with a hammer
• when using spring hooks
• when loosening or inserting springs, snap rings and gripping rings
• when soldering
• when using solvents, cleaning agents or other chemicals
Protective Equipment
Warning: Risk of injury in case of missing or faulty protective equipment.
• After performing maintenance work, attach all safety equipment (covers, safety precautions,
ground cables, etc.).
• Replace faulty parts and those which have become unusable.
Safety When Working with Electricity
Qualifications of Personnel
The following work may only be performed by instructed and trained electricians:
• work on the electrical assemblies
• work on the device while it is open and connected to the power supply
Maintenance Precautions
• Locate the emergency-stop or power switch so that it can be actuated in case of an
emergency.
• Unplug the device from the electrical outlet before performing the following work:
• removing or installing power supply units
• working in the immediate vicinity of exposed power supply parts
• mechanical inspection of power supply parts
• modifying the device circuits
• Ensure that the device is de-energized.
• Check the workplace for possible sources of danger, e.g. moist floors, defective extension
cables, faulty protective conduction connections.
Additional Precautions for Devices with Exposed Energized Parts
• Give another person the task of remaining near the workplace. This person must be familiar
with the location and operation of the emergency-stop and power switches and switch off the
power if danger arises.
• Use only one hand while working on electrical circuits when a device is switched on. Hold the
other hand behind your back or put it in your jacket pocket. This prevents the electricity from
flowing through your body.

Introduction
QL-900 Service Guide 10
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Tools
• Do not use worn or damaged tools.
• Use only tools and testing equipment that is suitable for the respective task.
If an Accident Occurs
• Proceed in a very cautions and calm manner.
• Avoid endangering yourself.
• Switch the power off.
• Request medical help (emergency physician).
• Call for first aid if necessary.

Troubleshooting
QL-900 Service Guide 11
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Chapter 2: Troubleshooting
This section is arranged by first the condition that might occur, and then by possible problems,
causes, and recommended solutions.
Power Problems
Interface Communication Problems
Condition Problem Solution
Power is ON, nothing happens. No power to printer. Check that power cord is plugged
in.
Check that power outlet is live.
Replace AC Adapter.
Lost time and date after printer is
shut down.
Internal Memory Battery dead. Replace CR 2032 lithium battery
on MPCA.
Condition Problem Solution
Printer does not respond to
software.
Connection problems. Check that the port is
communicating with the printer by
using another USB cable. Replace
the cable if necessary.
If the port cannot communicate
using USB cable, check the printer.
If port cannot communicate using
USB cable and the printer is OK,
check USB port on computer.
Printer not responding to software. Poor connection between printer
and computer.
Turn printer OFF and ON again.
Check connections.

Troubleshooting
QL-900 Service Guide 12
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Feeding Problems
Service Station
Condition Problem Solution
Failure to feed No power to printer. Check that power buttons are ON
(Control Panel and Main Power)
and that the power cord is plugged
in.
Material is out of specification. Maximum thickness is 0.3 mm.
Motor failure. Check that motor is receiving
power from the power supply.
No power. See “Power Problems” on page 11.
Jams Media path obstruction. Clear jam and remove pieces
remaining under printhead.
Media not loaded properly. Instruct operator in proper loading
of media.
Media curled or bent. Uncurl media.
Condition Problem Solution
Motor stalls • Jammed gear train due to
broken post or improperly
seated gears.
• Squeegee blade wedged, not
seated properly.
• Debris build-up on blade and
rollers, increasing friction.
• Bad motor.
1. Check each of possible causes
and correct if possible: reseat
gears and/or squeegee, clean
debris from blade and rollers.
2. Retest.
3. If motor is still stalled, replace
motor.
Color mixing Wiper roller is saturated.
Squeegee blade is wedged, not
seated properly, or bowed.
1. If saturated, clean or replace
roller.
2. Reseat squeegee.
3. If squeegee is bowed, adjust
squeegee blade.

Troubleshooting
QL-900 Service Guide 13
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Printhead
Condition Problem Solution
Missing parts of letters or text. Air and bubbles blocking nozzles.
Printhead is dry.
Clean printhead using recirculation,
priming, or cycles of depriming and
priming found on the printer
touchscreen or in the Printer
Toolbox.
Rehydrate the printhead using
distilled water and a wet, clean,
lint-free cloth.
Air bubbles often disappear with
printer use.
Print shows regularly missing or
misdirected nozzles or ink color
mixing.
Debris on printhead. Perform startup routine.
Clean the printhead using a
cleaning level on the printer
touchscreen or in the Printer
Toolbox.
Wipe the printhead manually with
distilled water and a wet, clean,
lint-free cloth.
Replace the printhead.
Ink mixing - Mixed or muddy colors. Ink flooding, air in printhead, or a
dirty printhead.
Clean the printhead using a
cleaning level on the printer
touchscreen or in the Printer
Toolbox.
Wipe the printhead manually with
distilled water and a wet, clean,
lint-free cloth.
No print or crisp blocks of missing
drops.
Electrical failure or poor electrical
connection.
Reseat the printhead.
Replace the printhead.
System will not reprime ink after
replacing the printhead cartridge.
Printhead nozzles are dry. Wipe the printhead manually with
distilled water and a wet, clean,
lint-free cloth.
Ink tanks may be 1/3 full or less. Replace the ink tanks.
Ink blobs or excessive ink from
nozzles.
Printer left idle or stored too long
with ink still in hoses.
Ink may congeal and eject all at
once or cause a blockage that
builds enough pressure to cause
the hose to detach.
Deprime and clear ink from printer
hoses and printhead before storing
or leaving the printer idle for long
periods of time.

Troubleshooting
QL-900 Service Guide 14
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Printing Problems
Condition Problem Solution
Ink tank installed, no ink level
indication in Toolbox
Ink tank contacts are dirty,
preventing printer/ink tank
communication.
Remove ink tank(s).
Clean prism and QA chip contacts.
See QL-900 User Guide.
Extra lines; losing data Database problem. Check data in database program.
Improper output (address
information out of order,
misfeeding, etc.)
Wrong interface settings. Check software or database on
PC.
Static electricity. Close software, then turn printer
OFF and ON.
Dirty media sensor. Clean media sensor.
Media jams Misfeeds.
Media is curled or bent.
Media is too thin.
Label Rolls: Adjust unwinder/
winder speed.
Fanfold Labels: Check if labels are
stuck together.
Uncurl media.
Minimum media thickness is 0.1
mm.
No communication Improper cabling / connector. Use a proper cable.
Unit not receiving power. Check plug connections, ON/OFF
switch, and fuse on back panel.
Print too light or missing character
dots
Clogged or dirty printhead. Check the printhead.
Running out of ink. Check the ink tanks.
Blurry address Image is not sharp. Clean the printhead using a
cleaning level on the printer
touchscreen or in the Printer
Toolbox.
Replace ink tanks or change the
printer resolution setting.
Check media thickness.
Split line of type A line of type does not match up. Check media thickness. Minimum
thickness for material is 0.1 mm.
Increase resolution of print.

Troubleshooting
QL-900 Service Guide 15
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Errors and Warnings
Printer Alert Window Messages
Messages sent from the driver are displayed on the PC screen in a small popup window.
Feeding problems Misfeeds. Label Rolls: Adjust unwinder/
winder speed.
Fanfold Labels: Check if labels are
stuck together.
Check if labels are sticking
together.
At start of a job, media runs and
stops without printing.
Printer not set for type of media
being used.
Blackmark sensor not reading
blackmark on media (too light) or
notches on media not deep enough
(less than 1/4” deep).
Reset printer for type of media
used.
Notched Media: Check notch
depth.
Condition Problem Solution
Message Solution
Cleaning in Progress Wait until the message disappears. The printer will start
printing your job once the cleaning process is complete.
Incompatible Printhead Remove and reinsert your printhead cartridge. Replace
the printhead.
Incorrect … Ink Tank Replace the ink tank.
…. Ink Low
Example: Black Ink Low
Reorder ink.
…. Out of Ink
Example: Cyan Ink Out
Replace empty ink tank.
Load Paper Out of paper. Load media into the printer and press the
PAUSE/RESUME button to resume printing.
Mechanical Jam Check for and remove obstruction, then press PAUSE/
RESUME button to resume printing.
Check/Clean sensors. If the problem persists, contact
technical support.
Missing Printhead Remove the printhead cartridge. Check/Clean electrical
contacts. Reinsert the printhead. Replace the printhead. If
the problem persists, contact technical support.

Troubleshooting
QL-900 Service Guide 16
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Multiple Inks Low Reorder ink.
Multiple Ink Tanks Out Replace empty ink tanks.
Multiple Ink Tanks are missing Insert missing ink tanks.
Clean electrical contacts and reseat ink tanks.
Multiple Unauthorized Ink Tanks Remove and reinsert the ink tank. Replace the ink tank.
Paper Jam Remove jammed media. Check for proper feed setup then
press the PAUSE/RESUME button to resume printing.
Check/Clean the sensors. If the problem persists, contact
technical support.
Printhead Latch Open Ensure the printhead cartridge has been inserted properly,
then close and lock the printhead latch.
Print Zone Assembly (Clamshell)
Open
Check to be sure the clamshell is completely closed and
latched.
The … Ink Tank is missing Insert the missing ink tank.
Clean electrical contacts and reseat the ink tank.
Unauthorized … Ink Tank
Installed
Replace the ink tank.
Unauthorized Printhead Replace the printhead cartridge.
Message Solution

Troubleshooting
QL-900 Service Guide 17
Confidential, Not for Redistribution
Toolbox System Status Messages
Use the touchscreen or Toolbox screen to quickly determine and locate a problem in the printer.
The status indicator shows ERROR in a red box. The printer graphic icon highlights the printer and
system affected. The system status information displays the basic problem (in red). Ink levels
display the ink status. Control buttons (at the screen bottom) let you perform often-used tasks
without leaving the screen.
Listed below are some of the messages that may appear in the system status.
System Status Source Solution
PAPERPATH_END_OF_ROLL Out of media. Load a new roll of media into the
printer. Tap the Clear Error button
and then tap the Pause/Resume
button on the Job screen to resume
printing.
Unwinder label tension arm has hit
its upper or lower limit.
Verify that the unwinder is threaded
correctly and the speed is set
correctly.
The end of the media did not
release from the roll core. The tape
is too strong.
Try to use stock that has soft-
release tape holding the media to
the cardboard core.

Troubleshooting
QL-900 Service Guide 18
Confidential, Not for Redistribution
PAPERPATH_PAPERJAM
Depending on where the media
stops/jams, it is also possible for
the printer to display:
PAPERPATH_FEED_TIMEOUT
Media jam detected.
The printer has detected that one
(or more) media sensors are
blocked (interrupted).
Carefully remove jammed media
from the printer and close the print
engine. System status message in
red should go away.
Touchscreen and Toolbox
Paperpath Sensor indicators
should change from red to green.
After jam is cleared, you can:
Label Rolls: Adjust unwinder/
winder speed.
Fanfold Labels: Check if labels are
stuck together.
Uncurl media.
Tap the Clear Error button and
then tap the Pause/Resume button
on the Job screen to resume
printing.
MAINTENANCE_BUSY Machine is performing a
maintenance procedure.
No action required. Wait for the
printer to finish.
DOOROPEN_PRINTHEAD Indicates that the printhead door is
open.
Verify that the printhead door is
closed. Make sure that the
printhead door switch (located at
the back center of the door) is
activated when the printhead door
is open and closed.
Switch damaged or disconnected. Use Scan Sensors in the Printer
Toolbox to check that the printhead
door switch is functioning.
DOOROPEN_INK Indicates that ink tank door is open. Verify that the ink tank door is
closed. Make sure that the ink tank
door switch (located at the upper
right corner of the door) is activated
when the ink tank door is open and
closed.
Switch damaged or disconnected. Use Scan Sensors in the Printer
Toolbox to check that the ink tank
door switch is functioning.
System Status Source Solution

Troubleshooting
QL-900 Service Guide 19
Confidential, Not for Redistribution
DATA_PATH_UNDERRUN Media is not moving from the entry
sensor to the exit sensor within a
specified time.
Possible issue with format or
orientation of job being sent.
Dirty encoder wheel.
Check/Clean the media transport
rollers. Check/Clean the sensors
and reflector.
Try changing the orientation setting
in software/driver or setting a
different media size.
If the problem persists, contact
technical support. They should
check/clean the encoder wheel.
INK_LOW_X One or more ink tanks are low on
ink.
X = Color.
MULT = More than one tank color.
Ink tank replacement will be
necessary soon. Reorder ink.
INK_OUT_YELLOW One or more ink tanks are out of
ink.
X = Color.
MULT = More than one tank color.
“Out” = System calculated that
250ml of ink was drawn from the
tank or visible ink sensor sees no
ink in tank prism.
Open the ink tank door. Replace
empty ink tank(s).
Verify that ink tanks are seated
firmly and latches are fully closed.
Close the ink tank door and tap the
Clear Error button. The ink levels
should fill in.
Note: A premature visible ink “Out”
condition can occur if the printer is
not on a sturdy, level surface.
CARTRIDGE_MISSING_MULT
or
CARTRIDGE_MISSING_X
Ink tank is missing or not
recognized (obtained from an
unauthorized reseller).
X = color (C M Y K1 K2)
MULT = more than one tank color.
Insert the missing ink tank or move
ink tank in and out to improve the
connection. Check/clean the ink
tank contacts.
Tap the Clear Error button and
then tap Pause/Resume button on
the Job screen to resume printing.
MECH_FAIL_PERMANENT
ERROR on System Status screen.
Check the Printer Graphic to
determine which component has a
problem or failed:
Service Station, Ink Valve, or
Printhead (usually indicated with a
steady ?)
Mechanical error
One of the printer's mechanical
components was not properly
registered at the expected position.
Mechanical failure or sensor
failure.
Visually inspect the component
stated as a reason for failure.
Using the Scan Sensors page in
the Printer Toolbox, perform toggle
test on sensor responsible for
registration of failed mechanical
component position.
Try restarting the printer.
If the problem persists, call for
service.
System Status Source Solution

Troubleshooting
QL-900 Service Guide 20
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[Crit 63 03-phead offline
cancelpage restart]
Dirty/Damaged printhead contacts
at the printhead or board.
Try restarting the printer.
Try replacing the printhead.
If the problem persists, call for
service.
ONLINE
ERROR on System Status screen.
Printer Graphic shows Printer
Service Station as “?”.
Service station position sensors
are damaged or malfunctioning.
Check service station position.
Check for mechanical jam.
Try restarting the printer.
If the problem persists, call for
service.
MECH_CANCELPAGE Job was canceled by the user
pressing the Cancel Job button.
Wait until the print job has cleared
from the printer. Then manually
clear the job from the computer's
print queue. Send a new print job.
PRINTHEAD_MISSINGQA
Printer Graphic shows Printer
Printhead as “?”.
Printhead missing or printhead not
making proper connections.
Remove the printhead, clean the
contacts, and reinstall the
printhead.
Replace the printhead. Refer to the
QL-900 User Guide for removing
and installing the printhead
cartridge.
Try restarting the printer.
If the problem persists, call for
service.
PRINTHEAD_UNPRIMED Printhead unprimed.
Printhead latch is open and/or the
door is open.
Printhead priming process has
failed.
After installing the printhead you
must close the printhead latch and
close all doors to start the priming
process.
Remove the printhead cartridge,
wet the print nozzles using distilled
water, and reinstall printhead
cartridge. Refer to the QL-900 User
Guide for removing and installing
the printhead cartridge. If you
continue to have trouble priming
the printhead, check for kinked or
pinched ink tubes.
Try restarting the printer.
If the problem persists, call for
service.
System Status Source Solution