Printer Applicator does not apply the label.
The Panther Printer is a combination of two machines. The Zebra or SATO print engine, and the Panther machine which manages the label feed and apply processes. When the label prints out fine but does not apply to the box the issue is typically a communication, or sequence issue. If the same problem occurs repeatedly even though the label is removed from the tamp, the tamp has been cycled using the "Apply" button, and the system is "ready" the problem is the print trigger photo eye is out of alignment, so the system doesn't know that a box has arrived at the printer. Check all photo eyes on the conveyor just ahead of the Print & Apply machines/frame.
A secondary cause can be a loose connection on a custom cable on the back of the Zebra/SATO Print engine. Please see the image below for the location of this cable and check that it is secure at both ends.
This cable is the link between the print engine, and the Panther Machine. If the "Label Ready" signal can't get through, the applicator won't come down and apply to the box.
A third possibility is that the network cable connection, or the apply trigger signal cable connection to the Panther machine is loose or faulty and the controls signals are not being received properly. Check all cable connections to the Panther & Zebra machines.