Zebra® GK420t™ Desktop Thermal Printer User Guide
ii 980610-001 Rev.
iii ©2010 ZIH Corp. G-Series, GK420t, ZBI, ZBI 2.0, ZBI-Developer, Uni-Ribbon, ZebraDesigner, ZebraNet, EPL, EPL2, ZPL, ZPL II, OpenACCESS and all product names and numbers are Zebra trademarks, and Zebra, the Zebra head graphic, ZPL, ZPL II, Element Energy Equalizer circuit, E3 Circuitand, and ZebraNet are registered trademarks of ZIH Corp. All rights reserved. All other trademarks are the property of their respective owners.
iv FCC Compliance Statement This device complies with Part 15 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. This equipment has been tested and found to comply with the limits for Class B Digital Devices, pursuant to Part 15 of the FCC Rules.
About This Document This section provides you with contact information, document structure and organization, and additional reference documents. Contents Who Should Use This Document . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi How This Document Is Organized . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi Contacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
vi About This Document Who Should Use This Document Who Should Use This Document This User Guide is intended for use by any person who needs to operate or to troubleshoot problems with the printer. How This Document Is Organized The User Guide is set up as follows: 980610-001 Rev. C Section Description Introduction on page 1 This section describes what you get in your shipping box and provides an overview of printer features.
About This Document Contacts Contacts Technical Support via the Internet is available 24 hours per day, 365 days per year. Web Site: www.zebra.com E-mail Back Technical Library: emb@zebra.com Emaillist Self Service Knowledge Base: www.zebra.com/knowledgebase Online Case Registration: www.zebra.
viii About This Document Document Conventions Document Conventions The following conventions are used throughout this document to convey certain information. Alternate Color (online only) Cross-references contain hot links to other sections in this guide. If you are viewing this guide online in .pdf format, you can click the cross-reference (blue text) to jump directly to its location. Command Line Examples Command line examples appear in Courier New font.
Contents About This Document . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v Who Should Use This Document . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi How This Document Is Organized . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi Contacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
x 3 • Print Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Determining Printer Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Localizing the Printer Status Configuration Label . . . . . . . . . . . . . . . . . . . . . . . . . . . . Long Term Printer In-activity or Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thermal Printing . . . . . . . . . . . . . . . .
xi 6 • Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 Status Light Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Status Light Error Resolutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Print Quality Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Manual Calibration .
xii Notes • ___________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ _______________________________________________________
1 Introduction This section describes what you get in your shipping box and provides an overview of printer features. This includes procedures that describe how to open and close the printer and report any problems. Contents GK Series Thermal Printers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . What’s in the Box? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Unpack and Inspect the Printer .
2 Introduction GK Series Thermal Printers GK Series Thermal Printers The Zebra® GK model is the best value in a desktop thermal printer. The GK420t™ printer provides thermal transfer and direct thermal printing at speeds up to 5 ips (inches per second) at a 203 dpi (dots per inch) print density. The GK420t™ supports both ZPL™ and EPL™ Zebra printer programming languages and a wide variety of interface and feature options.
Introduction What’s in the Box? What’s in the Box? Save the carton and all packing materials in case you need to ship or store the printer later. After unpacking, make sure you have all parts. Follow the procedures for inspecting the printer to familiarize yourself with printer parts so you can follow the instructions in this book.
4 Introduction What’s in the Box? Your Printer Status Light Feed Button Release Latches Release Latches Interface Connectors Fan-Fold Media Entry Slot DC Power Power Receptacle Switch Opening the printer To access the media compartment, you must open the printer. Pull the release latches towards you and lift the cover. Check the media compartment for loose or damaged components.
Introduction What’s in the Box? Printer Features Printhead Ribbon Roll Holders Take Up Spindles Supply Spindles Ribbon Trailer Sensor (hidden from view) Roll Holders and Media Guides Media Guide Stop BlackLine Sensor Web (Gap) Sensor Dispenser Option Platen Roller Head-Up Sensor (inside) Dispenser Door (open) Sensor 8/4/10 GK420t™ User Guide Pinch Roller Peel Bar 980610-001 Rev.
6 Introduction What’s in the Box? Operator Controls Power Switch Press up to turn ON or down to turn OFF the printer. Caution • The printer power should be turned off before connecting or disconnecting the communications and power cables. Power Switch Power OFF Power ON Power Switch 980610-001 Rev.
Introduction What’s in the Box? Feed Button • Tap the Feed button once to force the printer to feed one blank label. • Press the Feed button to take the printer out of a “pause” condition. The printer is put into “pause” by either a programming command or an error condition. See What the Status Light is Telling You on page 70 in the Troubleshooting chapter. • Use the Feed button for printer setup and status (see Feed Button Modes on page 80 in the Troubleshooting chapter).
8 Introduction What’s in the Box? Closing the printer 1. Lower the top cover. 2. Press down until the cover snaps closed. 980610-001 Rev.
2 Getting Started This section describes how to set up your printer for the first time and use the most common operating procedures for loading media. Contents Attaching Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Loading Roll Media . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Loading Transfer Ribbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10 Getting Started Attaching Power Attaching Power Important • Set up your printer so that you can handle the power cord easily if needed. To make certain the printer cannot carry electrical current, you must separate the power cord from the power supply receptacle or AC electrical outlet. Caution • Never operate the printer and power supply in an area where they can get wet. Serious personal injury could result! 1. Make sure the printer’s power switch is in the off position (down). 2.
Getting Started Loading Roll Media Loading Roll Media When you load media, you must place the roll onto the media hangers. You must use the correct media for the type of printing you require. Preparing Media Whether your roll media is inside or outside wound, you load it into the printer the same way. • Remove the outside length of media. During shipment, handling, or storage, the roll may become dirty or dusty.
12 Getting Started Loading Roll Media Placing the Roll in the Media Compartment 1. Open the printer. Remember that you need to pull the release latch levers toward the front of the printer. 2. Open the media roll holders. Pull the media guides open with your free hand and place the media roll on the roll holders and release the guides. Orient the media roll so that its printing surface will face up as it passes over the platen (drive) roller. 980610-001 Rev.
Getting Started Loading Roll Media 3. Pull the media so that it extends out of the front of the printer. Verify the roll turns freely. The roll must not sit in the bottom of the media compartment. Verify that the media’s printing surface is facing up. 4. Push the media under both of the media guides. Under Media Guides 5. Close the printer. Press down until the cover snaps closed. 8/4/10 GK420t™ User Guide 980610-001 Rev.
14 Getting Started Loading Transfer Ribbon Loading Transfer Ribbon Transfer ribbons come in several varieties and in some cases colors to match your application needs. Genuine Zebra® transfer ribbons are specifically designed for your printer and Zebra brand media. Using non-Zebra media or ribbons not approved for use in your Zebra® printer may damage your printer or printhead. • The media and ribbon types should be matched to provide you with optimal print results.
Getting Started Loading Transfer Ribbon 1. With the printer open, place a new ribbon roll on printer’s lower ribbon supply spindles. Rotate the roll until the notches align and lock into the left side of the supply hub. 2. Place an empty ribbon core on printer’s take-up spindles. Rotate the ribbon core until the notches align and lock into the left side of the take-up hub. You can find your first ribbon take-up core in the packing box.
16 Getting Started Loading Transfer Ribbon 3. Pull the transfer ribbon’s leader off the roll and attach it with the adhesive strip on the leader to the empty ribbon core on the supply spindle. Center the ribbon on the ribbon core. 980610-001 Rev.
Getting Started Loading Transfer Ribbon 4. Rotate the thumb wheel on the left side of the supply spindle towards the rear of the printer until the ribbon is pulled tight across the printhead. 5. Verify that the media is loaded and ready to print and then close the printer cover. 6. Press the Feed button to have the printer feed a minimum of 10 cm (4 inches) of media to remove slack and ribbon wrinkle, and to align the ribbon on the spindles. 7.
18 Getting Started Printing a Test (Printer Configuration) Label Printing a Test (Printer Configuration) Label Before you connect the printer to your computer, make sure that the printer is in proper working order. You can do this by printing a configuration status label. 1. Make sure the media is properly loaded and the top cover of the printer is closed. Then, turn the printer power on if you have not already done so.
Getting Started Pre-install Windows® Printer Drivers Pre-install Windows® Printer Drivers Zebra is changing the way you install and use your printer with your Windows based PC systems. We recommend that at minimum, the ZebraDesigner™ Windows® driver be preinstalled to take advantage of the advancements in ease of use and simplicity of the Windows operating systems since the release of Windows XP® SP2.
20 Getting Started Pre-install Windows® Printer Drivers Serial Port and Windows® operating systems The Windows operating system default settings for the serial port communication closely match the printer’s defaults settings with one exception; the data Flow Control settings. The Windows default data Flow Control setting is NONE. The G-Series printer requires data Flow Control set to Hardware.
Getting Started Connecting your Printer to a Computer Connecting your Printer to a Computer The Zebra® G-Series™ printers support a variety of interface options and configurations. These include: Universal Serial Bus (USB) interface, RS232 Serial, Parallel (IEEE 1284.4) and 10/100 Ethernet. • USB, Serial and Parallel • Optional: USB, Serial, and Ethernet (Wired) The Zebra Setup Utility is designed to assist you with installing these interfaces.
22 Getting Started Connecting your Printer to a Computer USB Interface Requirements Universal Serial Bus (version 2.0 compliant) provides a fast interface that is compatible with your existing PC hardware. USB’s “plug and play” design makes installation easy. Multiple printers can share a single USB port/hub. When using a USB cable (not supplied with your printer), verify that the cable or cable packaging bears the “Certified USB™” mark (see below) to guarantee USB 2.0 compliance. .
Getting Started Connecting your Printer to a Computer Serial Communications The printer automatically detects and switches the serial port to match common serial port cabling and signal connection configurations for DTE and DCE communications. The required cable must have a nine-pin “D” type (DB-9P) male connector on one end which plugs into the mating (DB-9S) serial port located on the back of the printer. The other end of this signal interface cable connects to a serial port on the host computer.
24 Getting Started Connecting your Printer to a Computer EPL Y Command Use the serial port setup (Y) command to change the communications settings on the printer. 1. With the host computer set at the same communications settings as the printer, send the Y command to change the printer to the desired settings. Note: the Y command does not support setting the data flow control, use the Xon/Xoff setting. 2. Change the host computer settings to match the new printer settings.
Getting Started Connecting your Printer to a Computer Parallel Port The required cable must have a 25 pin “D” type (DB-25P) male connector on one and a Centronics on the end (IEEE 1284 A-B parallel interface specification). Early models of GSeries printers originally supported parallel cables with two 25 pin “D” type (DB-25P) male connectors on both ends (IEEE 1284 A-A parallel interface specification). Parallel Cable 8/4/10 GK420t™ User Guide 980610-001 Rev.
26 Getting Started Connecting your Printer to a Computer Ethernet The printer requires UTP RJ45 Ethernet cable rated CAT-5 or better. For more information on configuring your printer to run on a compatible Ethernet based network, see the ZebraNet® 10/100 Internal Print Server manual. The printer must be configured to run on your LAN (local area network) or WAN (wide area network). The print server on board your printer can be accessed through the printer’s Web pages.
Getting Started After Your Printer is Connected After Your Printer is Connected Now that you have basic communication to your printer, you may want to test printer communications and then install other printer related applications, drivers or utilities. Testing Communications by Printing Verifying the print system’s operation is a relatively simple process. For Windows operating systems, the Zebra Setup Utility or the Windows ‘Printers and Faxes’ Control Panel to access and print a test label.
28 Getting Started After Your Printer is Connected Test Print with a Copied ZPL Command File for Non-Windows Operating Systems: 1. Create a text file with the following ASCII three characters: ~WC 2. Save the file as: TEST.ZPL (an arbitrary file name and extension name). 3. Copy the file to the printer. For DOS, a file sent to a printer connected to the system’s parallel port would be as simple as: COPY TEST.
3 Print Operations This section provides media and print handling, font and language support, and the setup of less common printer configurations. Contents Determining Printer Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Long Term Printer In-activity or Storage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Modes of Printing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30 Print Operations Determining Printer Configuration Determining Printer Configuration The G-Series™ printer uses a ZPL printer configuration status label to report the printer’s configuration status for both EPL and ZPL operations.The ZPL style label provides a more intuitive and functionally descriptive naming conventions than the EPL style printer status label. Operational status (darkness, speed, media type, etc.), installed printer options (network, interface settings, cutter, etc.
Print Operations Modes of Printing Modes of Printing You can operate this printer in many different modes and media configurations: • Direct thermal printing (which uses heat sensitive media to print). • Thermal transfer printing (which uses ribbon to heat transfer print to the media). • Standard Tear-Off mode allows you to tear off each label (or batch print a strip of labels) after it is printed.
32 Print Operations Print Media Types Table 1 • Types of Media Roll and Fanfold Media Media Type Non-Continuous Roll Media How It Looks Description Roll media is wound on a core that can be 0.5 to 1.5 in. (12.7 to 38.1 mm) in diameter. Labels have adhesive backing that sticks them to a liner, and they are separated by gaps, holes, notches, or black marks. Tags are separated by perforations.
Print Operations Replacing Supplies Determining Thermal Media Types Thermal transfer media requires ribbon for printing while direct thermal media does not. To determine if ribbon must be used with a particular media, perform a media scratch test. To perform a media scratch test, complete these steps: 1. Scratch the print surface of the media with a finger nail or pen cap. Press firmly and quickly while dragging it across the media surface.
34 Print Operations Adjusting the Print Width Replacing a Partially Used Transfer Ribbon To remove used transfer ribbon, perform the following steps. 1. Cut the ribbon from the take-up roll. 2. Remove the take-up roll and discard used ribbon. 3. Remove the supply roll and tape the end of any fresh ribbon to prevent it from unwrapping. When reinstalling a partially used supply roll, tape the cut end onto the empty take-up roll.
Print Operations Media Sensing Media Sensing The G-Series printer has automatic media sensing capability. The printer is designed to continuously check and adjust media length sensing for minor variations. Once the printer is printing or feeding media, the printer continually checks and adjusts the media sensing to accommodate for minor changes in media parameters from label to label on a roll and from roll to roll of media.
36 Print Operations Ribbon Overview Ribbon Overview Ribbon is a thin film that is coated on one side with wax, resin, or wax resin, which is transferred to the media during the thermal transfer process. The media determines whether you need to use ribbon and how wide the ribbon must be. When ribbon is used, it must be as wide as or wider than the media being used. If the ribbon is narrower than the media, areas of the printhead are unprotected and subject to premature wear.
Print Operations Ribbon Overview 4. Observe the results. Did flakes or particles of ink from the ribbon adhere to the label? If ink from the ribbon... Then... Adhered to the label The ribbon is coated on the outside and can be used with the G-Series printer. Did not adhere to the label The ribbon is coated on the inside and can not be used in the G-Series printer. Ribbon Scratch Test Perform the ribbon scratch test when labels are unavailable.
38 Print Operations Printing on Fan-Fold Media Printing on Fan-Fold Media Printing on fan-fold media requires you to adjust the media guide’s stop position. 1. Open the top cover. Fan-Fold Media Path 2. Adjust the media guide stop position with the green thumb wheel. Use a piece of the fan- fold media to set the stop position. Rotate the wheel toward you to open the guides wider. Rotate the wheel away from you to make the media guide narrower. 980610-001 Rev.
Print Operations Printing on Fan-Fold Media 3. Insert the media through the slot at the rear of the printer. 4. Run the media between the media guide and roll holders. 5. Close the top cover. After printing or feeding several labels: If the media does not track down the center (moves from side to side) or the sides of the media (liner, tag, paper, etc.) are frayed or damaged when exiting the printer, then the media guides may need further adjustment.
40 Print Operations Printing with Externally Mounted Roll Media Printing with Externally Mounted Roll Media The G-Series printer accommodates externally mounted roll media similar to the printer’s support of fan-fold media. The printer requires the media roll and stand combination to have a low initial inertia to pull the media off the roll. The G-Series™ motor has 30% more torque than the Zebra® 2800™ Series desktop printers to provide improved media handling and speed.
Print Operations Fonts and Your Printer Fonts and Your Printer The G-Series™ printer supports your language and font requirements with a variety of internal fonts, on-board font scaling, international font sets and character code page support, Unicode support, and font download. The G-Series™ printer’s font capabilities are programming language dependent. The EPL™ programming language provides for basic bitmapped fonts and international code pages.
42 Print Operations Fonts and Your Printer Identifying Fonts in Your Printer Fonts and memory are shared by the programming languages in the printer. Fonts can be loaded in many memory areas in the G-Series printer. ZPL programming can recognize EPL and ZPL fonts. EPL programming can only recognize EPL fonts. See the respective programmer guides for more information on fonts and printer memory.
Print Operations Stand Alone Printing Stand Alone Printing Your printer can be configured to work without being attached to a computer. The printer has the ability to automatically run a single label form. One or more downloaded label forms can be accessed and run with a terminal or wedge device or a Zebra® KDU (keyboard display unit) to call a label form. These methods allow the developer to incorporate data input devices, such as scanners or weight scales, to the printer via the serial port.
44 Print Operations Sending Files to the Printer Sending Files to the Printer Graphics, fonts and programming files can be sent to the printer from the Microsoft Windows operating systems by using the Zebra Setup Utilities (and driver), ZebraNet™ Bridge or Zebra® ZDownloader found on the user's CD or at www.zebra.com. These methods are common for both programming languages and the G-Series printers. Print Meter The G-Series printer has the capability to report printhead maintenance alerts.
4 Printer Options This section covers the common printer options and accessories with brief descriptions and how to get you started using or configuring your printer option or accessory. Contents Label Dispenser Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ZebraNet® 10/100 Internal (Wired) Print Server Option . . . . . . . . . . . . . . . . . . . . . . . . . Zebra® KDU — Printer Accessory. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
46 Printer Options Label Dispenser Option Label Dispenser Option The factory installed label dispenser option allows you to print a label with backing (liner/web) being removed from the label as it prints, ready for application. When printing multiple labels, removing the dispensed (peeled) label notifies the printer to print and dispense the next label.
Printer Options Label Dispenser Option 2. Lift the liner over the top of the printer and open the dispenser door. 3. Insert the label liner between the dispenser door and the printer body. 8/4/10 GK420t™ User Guide 980610-001 Rev.
48 Printer Options Label Dispenser Option 4. Close the dispenser door. 5. Press the Feed button to advance the media. 6. During the print job, the printer will peel off the backing and present a single label. Take the label from the printer to allow the printer to print the next label. Note: If you did not activate the label taken sensor to detect the removal of the dispensed (peeled) label with software commands, the printer will stack and eject peeled labels. 980610-001 Rev.
Printer Options ZebraNet® 10/100 Internal (Wired) Print Server Option ZebraNet® 10/100 Internal (Wired) Print Server Option The ZebraNet® 10/100 Internal Print Server (PS) is an optional factory installed device that connects the network and your ZebraLinkTM-enabled printer. The print server provides you with a browser interface for printer and print server settings.
50 Printer Options ZebraNet® 10/100 Internal (Wired) Print Server Option Printer Network Configuration Status Label G-Series™ printers with the ZebraNet® 10/100 Internal Print Server option on-board print an additional printer configuration status label for information needed to establish and trouble shoot network printing. The following printout is printed with the ZPL ~WL command.
Printer Options Zebra® KDU — Printer Accessory Zebra® KDU — Printer Accessory The Zebra® KDU (keyboard display unit) is a small terminal unit that interfaces with the printer for accessing EPL label forms stored in the printer. The KDU is strictly a terminal and does not have the capability to store data or set up parameters.
52 Printer Options KDU Plus™ — Printer Accessory KDU Plus™ — Printer Accessory The KDU Plus™ is a terminal device with memory for storing files and maintaining one or more remote printers. The KDU Plus has a larger laptop style keyboard than the Zebra’s original KDU design.
Printer Options ZBI 2.0™ — Zebra Basic Interpreter ZBI 2.0™ — Zebra Basic Interpreter Customize and enhance your printer with ZBI 2.0™ optional programming language. ZBI 2.0 allows Zebra printers to run applications and take input from scales, scanners and other peripherals—all without a PC or network connection. ZBI 2.0 works with the ZPL printer command language so that printers can understand non-ZPL data streams and convert them into labels.
54 Printer Options ZBI 2.
5 Maintenance This section provides routine cleaning and maintenance procedures. Contents Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cleaning the Printhead . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Media Path Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Platen Cleaning and Replacement . . . . . . . . . .
56 Maintenance Cleaning Cleaning When you clean the printer, use one of the following supplies that best suits your needs: Cleaning Supplies Order Quantity Intended Purpose Cleaning pens (105950-035) Set of 12 Clean printhead Cleaning swabs (105909-057) Set of 25 Clean media path, guides and sensors You can obtain cleaning supplies at www.zipzebra.com. The cleaning process takes just a couple of minutes using the steps outlined below.
Maintenance Cleaning Cleaning the Printhead Always use a new cleaning pen on the printhead (an old pen carries contaminants from its previous uses that may damage the printhead). Caution • The printhead becomes hot while printing. To protect from damaging the printhead and risk of personal injury, avoid touching the printhead. Use only the cleaning pen to perform maintenance. When you load new media, you can also clean the printhead. 1. Rub the cleaning pen across the dark area of the printhead.
58 Maintenance Cleaning Media Path Considerations Use a cleaning swab to remove debris, dust or crust that has built-up on the holders, guides and media path surfaces. 1. Use the alcohol in the cleaning swab to soak the debris to break up the adhesive. 2. Wipe the ridges to remove accumulated debris. 3. Wipe the inside edges of both edge guides to remove any built-up residue. 4. Wait one minute before closing the printer. Discard the cleaning swab after use.
Maintenance Cleaning Sensor Cleaning Dust can accumulate on the media sensors. 1. Gently brush away dust; if necessary, use a dry swab to brush away dust. If adhesives or other contaminates remain, use an alcohol moistened swab to break it up. 2. Use a dry swab to remove any residue that may be left from the first cleaning. 3. Repeat steps 1 and 2 as required until all residue and streaks are removed from the sensor. .
60 Maintenance Cleaning Platen Cleaning and Replacement The standard platen (drive roller) normally does not require cleaning. Paper and liner dust can accumulate without effecting print operations. Contaminates on the platen roller can damage the printhead or cause the media to slip or stick when printing. Adhesive, dirt, general dust, oils and other contaminates should be cleaned immediately off the platen.
Maintenance Cleaning 3. Lift the platen out of the printer’s bottom frame. 4. Clean the platen with the alcohol moistened swab. Clean from the center out. Repeat this process until the all of the roller surface has been cleaned. If there has been heavy adhesive build-up or label jam, repeat with a new swab to remove residual contaminates. Adhesives and oils, for example, may be thinned by the initial cleaning but not completely removed. 5. Install the platen in the printer.
62 Maintenance Cleaning 7. Align the platen with the gear to the left and lower it into the printer’s bottom frame. 8. Rotate the platen bearing latch release tabs down on the right and left sides towards the rear of the printer and snap them into place. Allow the printer to dry for one minute before closing the dispenser door, media cover or loading labels. Other Printer Maintenance There are no user level maintenance procedures beyond those detailed in this section.
Maintenance Replacing the Printhead Replacing the Printhead If you need to replace the printhead, read the procedure and review the removal and installation steps before actually replacing the printhead. Caution • Prepare your work area by protecting against static discharge. Your work area must be static-safe and include a properly grounded conductive cushioned mat to hold the printer and a conductive wrist strap for yourself.
64 Maintenance Replacing the Printhead 3. Use a blunt tipped tool to press the release tab on the right side and then the left side of the printhead. The tool diameter can be from 0.10 to 0.15 inches (2.5 to 3.8 mm). Insert the tool into the ribbon frame's printhead release access (the round) opening. Push the release tab and gently pull the printhead bracket down. 980610-001 Rev.
Maintenance Replacing the Printhead 4. Gently but firmly pull the two printhead cable bundles’ connectors off of the printhead. 5. Gently but firmly pull the green ground wire off the printhead. 8/4/10 GK420t™ User Guide 980610-001 Rev.
66 Maintenance Replacing the Printhead Replacing the Printhead 1. Push the left side printhead connector into the printhead. The connector is keyed to only insert one way. 2. Connect the green ground wire to the printhead. 3. Push the right side printhead wire connector onto the printhead. 4. Check that the ground wire and wire bundles are still connected to the printhead. 980610-001 Rev.
Maintenance Replacing the Printhead 5. Insert the printhead bracket’s the tab into slot in the ribbon frame assembly. Align the printhead spring slots to the five posts and snap the printhead into the ribbon frame. Post Slot Tab Spring Post Spring Slot Spring Slot 8/4/10 GK420t™ User Guide 980610-001 Rev.
68 Maintenance Replacing the Printhead 6. Place the left hand side of the ribbon guide into the ribbon frame. Swing the right side of the ribbon guide into the slot and snap it into position. 7. Verify that the printhead moves up and down freely when pressure is applied and remains locked when released. 8. Clean the printhead. Use a new pen to wipe body oils (finger prints) and debris of the printhead. Clean from the center of the printhead to the outside. See Cleaning the Printhead on page 57. 9.
6 Troubleshooting This section provides information about printer error reporting that you might need for printer troubleshooting. Assorted diagnostic tests are included. Contents Status Light Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Status Light Error Resolutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Print Quality Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
70 Troubleshooting Status Light Descriptions Status Light Descriptions What the Status Light is Telling You 980610-001 Rev.
Troubleshooting Status Light Error Resolutions Status Light Error Resolutions The following Status Error Light Resolution numbers correspond to the Status Light Description table on the previous page. Each error number may have one or more resolution to correct that error listed. 1. The printer is not receiving power. • Have you turned on the printer power? • Check power connections from the wall outlet to the power supply, and from the power supply to the printer. See Attaching Power on page 10.
72 Troubleshooting Status Light Error Resolutions 5. The media is out. • Follow the instructions for Loading Roll Media on page 11 in the Getting Started section, and then press the Feed button to resume printing. The ribbon is out. • The printer has sensed the end of the ribbon roll. Replace the ribbon. The printhead is open. • Close the top cover and then press the Feed button to resume printing. 6. The printer is paused. • Press the Feed button to resume printing. 7.
Troubleshooting Print Quality Problems Print Quality Problems No print on the label. • The media may not be direct thermal media when printing without ribbon (i.e. thermal transfer). The media may not be direct thermal media. See the test procedure Determining Thermal Media Types on page 33. • For thermal transfer printers, the media may not be outside wound or approved for use in the G-Series printer.
74 Troubleshooting Print Quality Problems There are long tracks of missing print (blank vertical lines) on several labels. • The printhead is dirty. Clean the printhead. • The printhead elements are damaged. The printing does not start at the top of the label or misprinting of one to three labels. • The media may not be threaded correctly. Follow the instructions for Loading Roll Media on page 11 in the Getting Started section. • The printer needs to be calibrated.
Troubleshooting Print Quality Problems A EPL label format was sent to, but not recognized by, the printer. • Is the printer in pause mode? If so, press the Feed button. • If the printer has label dispensing enabled, the printer may be waiting for the label to be removed. The liner/web must be properly threaded through the label dispenser mechanism (peeler) to correctly operate in label dispense mode, refer to Label Dispenser Option on page 46.
76 Troubleshooting Manual Calibration Manual Calibration Manual calibration is recommended whenever you are using pre-printed media or if the printer will not correctly auto calibrate. 1. Make sure media is loaded. 2. Turn on the printer power. 3. Press and hold the Feed button until the green status light flashes once, then twice and then continuing until the flash groups reach the group of seven flashes. Release the Feed button. 4. The printer will set the media sensor for the label backing being used.
Troubleshooting Troubleshooting Tests Troubleshooting Tests Printing a Configuration Label To print out a listing of the printer’s current configuration, refer to the one-flash sequence in Feed Button Modes on page 80 in this section. See Appendix: ZPL Configuration on page 93 to interpret the label. Recalibration Recalibrate the printer if it starts to display unusual symptoms, such as skipping labels. Refer to the two-flash sequence in Feed Button Modes on page 80 in this section.
78 Troubleshooting Resetting the Factory Default Values Resetting the Factory Default Values Sometimes, resetting the printer to the factory defaults may solve some problems. Refer to the four-flash sequence in Feed Button Modes on page 80 in this section. Communications Diagnostics If there is a problem transferring data between the computer and printer, try putting the printer in the communications diagnostics mode.
Troubleshooting Communications Diagnostics The following example of a communications DUMP mode printed out. The printout displays hexadecimal data 00h-FFh (0-255 decimal) with a unique character for each hexadecimal value displayed above the hexadecimal data. The blank lines between the lines of data are where serial port and Bluetooth data handling errors get logged.
80 Troubleshooting Feed Button Modes Feed Button Modes Power Off Modes With the printer power off, press and hold the Feed button while you turn on the power. Flash Sequence Amber - Red Flashing Action Firmware Download Mode - The printer starts rapidly flashing red to denote entry into the Firmware Download mode. Releasing the Feed button here will start initializing the printer for download.
Troubleshooting Feed Button Modes Power On Modes With the printer power on and top cover closed, press and hold the Feed button for several seconds. The green status LED will flash a number of times in sequence. The explanation at the right (Action) shows what happens when you release the key after the start specific number of flashes and before the next flash sequence starts. Flash Sequence * * ** Action Configuration Status - Prints a detailed printer configuration status label.
82 Troubleshooting Feed Button Modes Notes • ___________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ _____________________
A Appendix: Interface Wiring This section provides printer interface connection information. Contents Universal Serial Bus (USB) Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Parallel Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ethernet Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Serial Port Interface . . . . . .
84 Universal Serial Bus (USB) Interface Universal Serial Bus (USB) Interface The figure below displays the cable wiring required to use the printer’s USB interface. The printer requires cable or cable packaging that bears the “Certified USB™” mark to guarantee USB 2.0 compliance. 2 3 1 4 Pin Signal 1 Vbus - N/C 2 D- 3 D+ 4 Ground Shell Shield / Drain Wire For printer supported operating systems and drivers, see the software and documentation CD or visit the Zebra Web site at: http://www.
85 Parallel Interface Parallel Interface The printer’s parallel interface uses the IEEE 1284-A to 1284-B parallel interface cables. the host connector has a DB-25 pin male connector. The printer connector is a Centronics style connector. Early model G-Series printers had DB-25 pin connector on the printer side, as well as, the host connection side (IEEE 1284-A to A parallel cable). HOST DB-25 Pin No. STROBE~ DATA 0 DATA 1 DATA 2 DATA 3 DATA 4 DATA 5 DATA 6 DATA 7 ACK~ BUSY PAPER ERR.
86 Ethernet Interface Ethernet Interface This interface requires a UTP RJ45 Ethernet cable rated CAT-5 or better. The table below provides the cable’s pinout assignments. Signal Tx+ TxRx+ — — Rx— — Pin 1 2 3 4 5 6 7 8 Signal Tx+ TxRx+ — — Rx— — 5 6 7 8 4 3 2 1 980610-001 Rev.
87 Serial Port Interface Serial Port Interface Pin 1 2 3 4 5 6 7 8 9 Description Not used RXD (receive data) input to the printer TXD (transmit data) output from the printer DTR (data terminal ready) output from the printer -- controls when the host may send data Chassis ground DSR (data set ready) input to the printer RTS (request to send) output from the printer -- always in the ACTIVE condition when the printer is turned on CTS (clear to send) - Not used by the printer +5 V @ 0.
88 Serial Port Interface Connecting the Printer to a DTE Device DB-25S Connector to DTE Device (PC) DB-9P Connector to Printer DB-9S Connector to DTE Device (PC) DB-9P Connector to Printer Connecting the Printer to a DCE Device DB-25S Connector to DCE Device 980610-001 Rev.
B Appendix: Dimensions This section provides external printer dimensions. Contents External GK Printer Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 Label Dispenser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 8/4/10 GK420t™ User Guide 980610-001 Rev.
90 External GK Printer Dimensions External GK Printer Dimensions 7.90 7.50 2.46 10.05 All dimensions are in inches 3 9.5 13.58 4.05 0.52 10.05 7.50 1.84 980610-001 Rev.
91 External GK Printer Dimensions Label Dispenser 7.90 7.50 2.46 10.25 10.96 8/4/10 GK420t™ User Guide 980610-001 Rev.
92 External GK Printer Dimensions Notes • ___________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ _________________________
C Appendix: ZPL Configuration This section provides a basic overview of managing printer configuration, the Configuring Status Printout, and Printer Memory Printouts. Contents Managing the ZPL Printer Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 ZPL Configuration Status to Command Cross-reference. . . . . . . . . . . . . . . . . . . . . . . . . 95 Printer Memory Management and Related Status Reports . . . . . . . . . . . . . . . . . . . . . . .
94 Managing the ZPL Printer Configuration Managing the ZPL Printer Configuration The ZPL printer is designed to allow you to change printer settings dynamically for fast first label out printing. Printer parameters that are persistent, will be retained for following formats to use.
95 ZPL Configuration Status to Command Cross-reference ZPL Configuration Status to Command Cross-reference The Printer Configuration Label, shown below, provides a listing of a majority of the configurations settings that can be set by ZPL command. Figure 2 • Configuration Label Printout Sensor Settings used for Service Purposes 8/4/10 GK420t™ User Guide 980610-001 Rev.
96 ZPL Configuration Status to Command Cross-reference Table 2 • ZPL Commands and Configuration Receipt Callout Cross-Reference Command Listing Name Description ~SD DARKNESS Default: 10.0 ^PR PRINT SPEED Default: 6 IPS / 152.4 mm/s (max.
97 ZPL Configuration Status to Command Cross-reference The configuration settings listed here resume after the TAKE LABEL sensor value. These listings contain printer features seldom changed from default or provide status information (e.g. Firmware Version).
98 Printer Memory Management and Related Status Reports Printer Memory Management and Related Status Reports To help you manage printer resources, the printer supports a variety format commands to manage memory, transfer objects (between memory areas, import and export), object naming, and provide various printer operating status reports. They are very similar to the old DOS commands like DIR (directory listing) and DEL (delete file).
99 Printer Memory Management and Related Status Reports Table 4 • Object Management and Status Report Commands Command 8/4/10 Name Description ^WD Print Directory Label Prints a list of objects and resident bar codes and fonts in all addressable memory locations ~WC Print Configuration Label Prints a configuration Status Receipt (Label) Same as Feed Button mode one flash routine ^ID Object Delete Deletes objects from printer memory ^TO Transfer Object Used to copy an object or group of objec
100 Printer Memory Management and Related Status Reports Notes • ___________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __
