Zebra Technologies GC420t

Maintenance

Replacing the Printhead

5/22/2012 GC420t™ User Guide P1052686-001

6. Unplug both bundles of printhead wires from their connectors.

Replacing the Printhead

The new print head comes with the clip and ground screw attached.

1. Align the printhead and bracket to plug the left and right connectors into the black and

white wire bundles.

Contents

Main Page iii iv FCC Compliance Statement Environmental Management Page vi Who Should Use This Document How This Document Is Organized vii Contacts Contacts viii Document Conventions Contents Page Page Page Introduction GC420t Thermal Printers Whats in the Box? Unpack and Inspect the Printer Your Printer Opening the printer Printer Features Page Page Page Getting Started Attaching Power Loading Roll Media Preparing Media Placing the Roll in the Media Compartment Page Page Loading Transfer Ribbon Page Page Page Printing a Test (Printer Configuration) Label 20 Pre-install Windows Printer Drivers PlugNPlay (PnP) Printer Detection and Windows operating systems Page Connecting your Printer to a Computer Interface Cable Requirements Page 24 Serial Communications Autobaud ZPL ^SC Command EPL Y Command Resetting the Default Serial Port Parameters 2. While the status LED rapidly flashes amber and green, press the feed button. Serial baud, NO parity, 8 data bits, 1 stop bit and a HARDWARE and SOFTWARE (merged) data Page 27 After Your Printer is Connected Testing Communications by Printing Page Print Operations Determining Printer Configuration Long Term Printer In-activity or Storage Thermal Printing Modes of Printing Print Media Types Page Determining Thermal Media Types To perform a media scratch test, complete these steps: Replacing Supplies Adding a New Transfer Ribbon Replacing a Partially Used Transfer Ribbon Adjusting the Print Width Adjusting the Print Quality Media Sensing Ribbon Overview When to Use Ribbon Coated Side of Ribbon To determine which side of a ribbon is coated, complete these steps: 37 Ribbon Test with Adhesive To perform an adhesive test, complete these steps: Ribbon Scratch Test To perform a ribbon scratch test, complete these steps: Printing on Fan-Fold Media Page Printing with Externally Mounted Roll Media Externally Mounted Roll Media Considerations: Fonts and Your Printer Localizing the Printer with Code Pages Identifying Fonts in Your Printer Stand Alone Printing Sending Files to the Printer Print Meter Printer Options 46 Label Dispenser Option ^XA ^MMP ^XZ Page Page Zebra KDU Printer Accessory 50 KDU Plus Printer Accessory * - Not real values ( 45mA + 120mA + 25mA ) + 50mA <Max. Current Current Draw ZBI 2.0 Zebra Basic Interpreter Page Maintenance This section provides routine cleaning and maintenance procedures. Cleaning Cleaning the Printhead Media Path Considerations 57 Sensor Cleaning Platen Cleaning and Replacement Page Other Printer Maintenance Replacing the Printhead Page Page Page Troubleshooting Status Light Descriptions Status Light Error Resolutions Page Print Quality Problems No print on the label. The printed image does not look right. There are long tracks of missing print (blank vertical lines) on several labels. The printing does not start at the top of the label or misprinting of one to three labels. A ZPL label format was sent to, but not recognized by, the printer. A EPL label format was sent to, but not recognized by, the printer. Manual Calibration Troubleshooting Tests Resetting the Factory Default Values Communications Diagnostics Page Feed Button Modes Feed Button Modes Amber - Red Flashing Green Amber www.zebra.com Page Page Page Universal Serial Bus (USB) Interface Parallel Interface PRINTER DB-25 Pin No. Centronics Pin No. DB-25 to Centronics (Cable) Serial Port Interface Connecting the Printer to a DCE Device Page Page Page Page C 88 Managing the ZPL Printer Configuration ZPL Printer Configuration Format ZPL Configuration Status to Command Cross-reference Page Page Printer Memory Management and Related Status Reports ZPL Programming for Memory Management