zenpert 4T520 Series User Manual page 16

4. Push the print head release button to open the print head mechanism.
Gap sensor
Black mark
sensor
Platen roller
OPEN
5. Adjust the black mark sensor if
using black mark label.
Note:
The black mark sensor position is
moveable and the gap sensor is
fixed. Please make sure the gap or
black mark is at the location where
media gap/black mark will pass
through for sensing.
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