Reset and configure again qln420 Zebra Printer

Hi all see this video:


With a Java Servlet.

if you see the impresion is done, but eject 4 labels, not know why.


this is other video now form C# .net same problem.


in this other video, when i close the case, advance/eject 4 labels and not posicionate at the first of the label.


how to fix these problems?


and how to disable the printer sleep?


Much thanks.