Labels not printing
Should labels not be printing out of Navigator the first point to check is that the label station is running.
If this is running and still not printing check in the Navigator control panel under "Label Printer Admin" if you have anything stuck in the print queue this would mean your user is either not linked to a label station, or the label station is not running.
If there is nothing in the print queue but you still do not receive a label, this will be an issue with your PC connecting to the printer locally.
The first point of checking should be in your pc printers and devices > printer properties and print a test page. Should a test page still not print you will need to speak to your IT department as your PC is not connected to the printer.
Label Printing Incorrectly
Should labels be printing out of Navigator, but either printing extra blank labels or cropping the height/width this will be set on the local printer settings on the PC running the printing app as Navigator does not define any label sizes when printing.
The first point to check is in the printing preferences in your printers and devices and ensure your label size is set correctly.
Reset the label sizes on the printer
Should this still not work the Zebra GK420d has several functions to reset printer settings such as the label length, width etc.
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 most commonly used reset functions would be;
2 flashes resets the length of the label
4 flashes performs a factory reset
5 flashes resets the width of the label
Detailed Zebra Flash Sequences
1 Flash
Configuration Status - Prints a detailed printer configuration status label. The label can be used to verify printing, assist printer to computer communication configuration, maintenance, troubleshooting, and help us with customer care communications.
2 Flashes
Standard Media Calibration - The printer detects and sets media type and media length, and it adjusts the media sensors for optimal performance with the installed media. The printer will feed one to four labels.
Note: Users familiar with the Zebra EPL desktop printer use this Feed mode to replace power-up AutoSensing calibration.
3 Flashes
Serial Port Configuration - Applies only to printers with serial interface ports. To reset the communication parameters Press and release the Feed button while the LED rapidly flashes amber and green. For autobaud synchronization: Send the ^XA^XZ command sequence to the printer while the LED rapidly flashes amber and green. When the printer and host are synchronized, the LED changes to solid green.
NOTE: No labels will print during autobaud synchronization.
4 Flashes
Factory Defaults - Resets the printer to the default factory settings and modes. See the configuration label for a list of the primary settings affected by this Feed Mode option. Other settings are exclusively set, viewed and controlled by programming are also reset. The printer then performs a standard media calibration.
5 Flashes
Print Width Adjustment - Prints a succession boxes starting at the minimum print width and ending in the printer’s maximum print width in 4mm increments. Press the Feed button once when the printer has reached the desired maximum print width. Note that the printer driver and applications can override this setting.
6 Flashes
Print Darkness (Density) Adjustment - Prints a succession of barcode simulation patterns starting at the minimum darkness (print density/heat) and ending in the printer’s maximum darkness in increments of four (4) using the ZPL darkness setting range values. Press the Feed button once the pattern is clear and legible. Do not continue to increase the darkness setting. Bar code line widths may become distorted reducing readability. Note that the printer driver and applications can override this setting.
7 Flashes
Manual Media Calibration - The printer runs extensive tests to detect and set media type and media length, and then it adjusts the media sensors for optimal performance with the installed media. Manual calibration is recommended whenever you are using pre-printed media, print on the liner or if the printer will not correctly auto calibrate. A graphical profile of the media sensing will print. See Manual Calibration on page 65 for more details and
considerations
If the Feed button remains pressed after an 8-flash sequence, the printer exits the configuration mode when the Feed button is released.