1)  Why is the screen no longer visible to me because at the beginning, it looks erased, and the writing on the label is just as erased?
These two situations have their prayers for changing batteries. Specifically, the old batteries are over and they are no longer able to power the device.

2)  Can you tell me why why when I print the machine does not remove the label?
In this case there can be two problems: 

• Either the moped of the device that pulls the label has given up, or the tape is loaded with too much adhesive.
• If the adhesive is the problem, you can remove the label from the machine and manually pull the label from the box, until you feel it runs smoothly.