Zebra Technologies T402 - Manual (Page 40)

There are long tracks of missing print (blank vertical
lines) on several labels.
n The printhead is dirty. Clean the printhead according to the instructions
on page 39.
n The printhead elements are damaged. Replace the printhead (see
“Replacing the Printhead” on page 44).
The printing does not start at the top of the label, or
misprinting of one to three labels.
n The media may not be threaded under the media guides. Refer to
“Loading the Media” on page 5.
n The printer needs to be calibrated. Refer to “Auto Calibration” on
page 25.
n The correct media sensor may not be activated. Manual calibration
selects the media sensing method for the labels being used (refer to the
^MN command in the ZPL II Programming Guide).
n Verify that the Label Top (^LT) command is correctly set for your
application (consult the ZPL II Programming Guide).
A label format was sent to, but not recognized by, the
printer.
n Is the printer in pause mode? If so, press the feed button.
n If the status LED is on or flashing, refer to “What the Status LED is
Telling You” on page 31.
n Make sure the data cable is correctly installed.
n A communications problem has occurred. First, make sure that the
correct communications port on the computer is selected. Next, verify
that the same handshaking is in use by both the printer and the computer.
Then, ensure that the baud rates of the printer and the computer match.
Refer to
“Communicating with the Printer” on page 29.
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