Turn on the printer with the lid closed. wait till it goes solid green.

Press and hold the feed button on top it will start to go through a series of flashes they mean the folowing:
the longer u hold the more it will flash, I# hold for 3 seconds it will flash 1, then 1,2, then 1,2,3 when you let go that is the Mode you are using:

1 flash, Printer calibration (zebra says they dont use)

2 flashes, media calibration (they dont use)

3 Flashes Cable reset

4 Flashes Default Settings (this is the “DUMP” that we should use.

5 flashes print with test feed (they dont use this)

6 Flashes set darkness of the printer ( we dont use this we can set the darkness of the printer through the driver)

So in short to do a DUMP on the GKT 420 turn it on wait for a green light, PRESS and HOLD the feed button until it flashes (1,) (1,2) (1,2,3) (1,2,3,4) let go after the (1,2,3,4) it will do a dump process, once that is done press the feed button one more time, and it is now dumped how zebra recommends doing it.

In answer book