If you are using CardExchange software, please follow the instruction below first:
Whiteline on CardExchange Printout Using DNP Printer
If the issue is not resolved, proceed with the instructions below.
Press and hold the Menu button and Middle button at the same time.
After approximately 3 seconds, release the Menu button.
Continue holding the Middle button.
Enter the Maintenance menu.
Adjust the following settings as required:
OFFSET PRT Y
OFFSET TRF X
The required adjustment depends on the type and direction of the misalignment.
Please refer to the image below for the appropriate adjustment.