My Zebra printer displays a red or orange light, never green, and will not print.

Check to make sure the ribbon is in properly, the labels are in properly, and, for Zebra 2742s, the carriage that holds the ribbon is snapped in place on both sides. For the Zebra 2844, make sure the lid is tight on both the left and the right side.

Below: carriage “snapped” into place in a Zebra TLP 2742:
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Below: Zebra TLP 2844, with ribbon carriage on the top:
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