1. Unit Test Calibration Training
(QL420+ & RW420)
Mobile Printers
Inst. Notes: (Estimated time 45-minutes per printer on QL and RW 10 minutes for MZ) depending on training kit available and skill set of delegates)
Introduce and point out the location of the key components for servicing/troubleshooting and replacement.
Demonstrate the removal and replacement of each of these items:
Show delegates videos available on these procedures; run them as needed from your PC. (refitting MLB as an example before they do it).
Thermal Printhead
Platen Roller
MLB
Drive Motor
Delegates perform the same procedures
NB: Media sensors cannot be removed.

2. Unit Test: Overview
Unit test is software which is used with the QL and RW range of mobile printers and is used to do the following:
Test and calibrate all the sensors of the printer. This includes the bar sensor, gap sensor, peel sensor, media width sensor and head open sensor.
Test the communication ports of the printer. This includes the serial port and the USB port.
Test the LCD and keypad.
Test the print quality of the printer and the printhead.
Unit test also sets and verifies the serial number of the printer and sets all the other parameters of the printer.
Unit test is an essential piece of software when replacing the MLB of a printer.

3. Preparation: Unit Test
Please ensure you have all of the following for this training:
Latest version of Unit test downloaded and installed (v.518 or later)
A QL printer with a fully charged battery. (Preferably a QL420+)
Printed instructions.
Grey & white calibration swatches. (P/N: AA & AA )
Plus…

4. Preparation: Unit Test1.
Media width sense test fixtures.
(P/N: AF , AF , AF & AF ) 2.
Serial Cable (P/N: BL ) 3.
USB Cable
(AT )

5. Preparation: Unit Test
Connect the serial cable to the serial port (com1) of the computer.
Connect the USB cable to the USB port of the computer.

6. Preparation: Unit Test
Ensure there are no Zebra printer drivers loaded in windows as this may prevent unit test from communicating with the printer. If any Zebra printer drivers are loaded please delete them.
Also make sure there are no other applications running which use the serial com ports as this may also prevent unit test from communicating with the printer.

7. Preparation: Unit Test
Load media into the printer and print a configuration label by pressing and holding the feed button then press and release the power button and keep the feed button pressed. When printing starts release the feed button.
Connect the serial cable to the serial port of the printer. Check the baud rate of the printer on the configuration label.

8. Unit Test
Run unit test.
Click on options and then baud rate and set the printer baud rate to the same the baud rate printed on the configuration label. In this example the baud rate of the printer is bps. Then click on ok.

9. Unit Test
Click on options and then ports and check the Printer Port is set to Com1. Then click on ok.

10. Unit Test
In this example we will be testing a QL420 printer using unit test. Select Unit Test (QL Series) by clicking on option 4.
A window will then appear asking to check the printer is connected, click on ok.

11. Type in or scan in your name and then click on Ok
Unit Test
Type in or scan in your name and then click on Ok

12. Scan or type in the serial number of the printer
Unit Test
Scan or type in the serial number of the printer

13. Unit Test
The serial number and CSD/PCC number is located on the back of the printer.

14. Unit Test
Scan or key in the CSD number and then click on continue. A window showing the entered CSD number will then appear. Click
on Ok. 1. 2.

15. Unit Test
Scan or type in the CSD number and then click on continue. A window showing the entered CSD number will then appear. Click on Ok.

16. Unit Test
Unit test will automatically set the default printer settings based on the CSD number that was entered. Ensure the options are correct then click on Continue.

17. Unit Test
The Media Sensor Test calibrates the media width sensor of the printer. Remove the media and bring end-caps to rest position as shown. Then click on Test.

18. Unit Test
When prompted insert AF (2” media width sense fixture) into the printer as shown and click on Ok.

19. Unit Test
Then when prompted remove AF and place AF (4” media width sense fixture) into the printer as shown. Then click on Ok.

20. Unit Test
After a short time unit test will show the Media sense reading. Click on Ok.

21. Unit Test
Unit test should then show Pass calibration. Click on Ok. If unit test fails calibration then the media width sensor may be faulty.

22. Unit Test
Bar Sensor Calibration calibrates the bar sensor of the printer.

23. Unit Test
Insert the grey test swatch (p/n AA ) as shown below and close the media cover and latch. Then click on Test.

24. Unit Test
Unit test will then calibrate the bar sensor. Once the calibration process has completed click on ok to verify calibration.

25. Unit Test
When calibration has been verified remove the swatch from the printer. Then click on ok to continue. If calibration fails the bar sensor may be faulty.

26. Unit Test
Peeler Sensor Calibration calibrates the peel sensor of the printer.

27. Unit Test Close media cover and latch (no media loaded at this point).
Stand printer on end (as shown below)
Slightly insert the grey test swatch above the peel bar and below the tear bar (and peel sensor) as shown below. The swatch will push approx 2mm into the media exit slot. Then click on test.

28. Unit Test
Unit test will then calibrate the peel sensor. Once the calibration process has completed click on ok to verify calibration.

29. Unit Test
When calibration has been verified remove the swatch from the printer. Then click on ok to continue. If calibration fails the peel sensor may be faulty.

30. Unit Test
Gap Sensor Calibration calibrates the gap sensor of the printer.

31. Unit Test
Insert the white test swatch (p/n AA ) as shown below and close the media cover and latch. Then click on Test.

32. Unit Test
Unit test will then calibrate the gap sensor. Once the calibration process has completed click on ok to verify calibration.

33. Unit Test
When calibration has been verified remove the swatch from the printer and load gap media as shown below. Close the media cover and latch. Then click on ok to continue. If calibration fails the gap sensor may be faulty.

34. Unit Test
Test labels will then be printed. If the labels have been printed correctly click on ok.

35. Unit Test
Peeler sensor test will test the operation of the printer in peel mode
Open the latch and open the peeler bar of the printer as shown below.

36. Unit Test
Make sure only a small part of the backing is loaded inside the printer and then close the latch leaving the backing under then peeler bar as shown below. When the latch is closed the printer may feed to the start of the next label.
Stand printer on end and click on continue.

37. Unit Test Unit test will then printer test labels.
When the first label has printed the second label will not be printed until the first label has been removed. Repeat this for the second and third label. Once the test has been completed click yes.

38. Unit Test
This test will determine if the unit has an issue printing on tag stock. Load tag media (or bar media) into the printer and click continue.

39. Unit Test
After the printer has printed the first label scan the barcode of the label and the printer will then print the next label. Repeat this for the second and third label.

40. Unit Test
After the third label has been printed and scanned click on continue.
If continue is not pressed within approx 30 seconds unit test will time out and will only give the option to exit.

41. Unit Test
Non S-Series test verifies that the compatibility switch is set to the normal position. Click on next to start the test.

42. Unit Test
After the test the printer will feed a label. Click next to continue. If the test fails check SW1 of the MLB is set to the correct position.

43. Unit Test
Open the printhead latch, ensure the beeper sounds and the media cover open icon is displayed on the LCD. Close the latch and unit test will proceed to the next screen. This test is time critical and each step must be performed within 10 seconds.

44. Unit Test
Unit test will automatically verify all the unit parameters to ensure they are set to the proper value. After verification the software will automatically move to the next screen.

45. Unit Test
Soft Power-down test will then be performed. Wait for the printer to power on and then click ok. Unit test will then proceed to the next screen.

46. Unit Test
Power ON/OFF key test will test the on/off key functions correctly. Press the on/off key to power on the printer.

47. Unit Test
Press the on/off to power off the printer. Then click on ok.

48. Unit Test
USB port test tests the usb port. Disconnect the serial cable and connect the usb cable.

49. Unit Test
When the Found New Hardware window appears click on cancel. Then click start on unit test.

50. Unit Test
Test labels will then be printed via the usb port. Disconnect the usb cable and reconnect the serial cable. Click continue.

51. Unit Test
Display test tests that the LCD is functioning correctly. Click on ok.

52. Unit Test
The LCD should be filled with black boxes as shown below. Click ok to continue.

53. Unit Test
Next click on continue.

54. Unit Test
The LCD will then display a number. Type the number on the display in the box and click continue.

55. Unit Test
Click on ok to continue.

56. Unit Test
Click on continue.

57. Unit Test
Unit test will prompt you to select whether or not a Life Test is to be performed. Click on yes.

58. Unit Test
A label will then be printed to verify the printer has passed testing. Make sure a fully charged battery is installed then click on continue.

59. Unit Test
A pre-defined number of life test patterns to exercise the printer and determine if the battery under test is maintaining a proper charge.

60. Unit Test
Testing of the printer is now complete.

61. Q&A