Hi GR5, thank you again for your support. I have not touched the gray cables because as soon as I removed the metallic cover the printer started to work.
What for me is not acceptable is that I've not bought a 50 bucks chinese toy where the "almost" cutted wires could be something usual to see.
Ultimaker2 costs 2500 dollars and I guess the price is not linked to the cost of the single parts, but this is the price to pay to have what Ultimaker defines in their home page:
Easy to use and reliable
Designed for non-expert and expert
Now I briefly summarize all the problems I found in the printer I received:
1) the X slider block was shifted on the right. As draw back the home microswitch (on the top-left of the printer) was not touched by the slider so that the stepper motors did not stop at home position
2) the other side of the slider was touching the internal right panel
(Thank you to Sander we fixed the problem)
3) the wires of the home microswitch were touching one of the motor belt
4) the bottom cable connecting the build plate was under the plate so that when then plate was lowered it was bandy
5) the Z stepper wires are "almost" cutted
6) the printer doesn't work with the metal cover installed
7) the wiring seems made by my 5 year old son
If this is the definition of easy to use, reliable and designed for non-expert then it's ok.
In addition to that, I sent several mails to support and sales but, up to now, I've not received any reply.