Hello CarloZ and welcome back to the HP Support Forums! Thank you for replying.
To summarize then, there is an issue with either:
1. The Printer USB Cable. (You can try another Printer USB Cable if you have not already)
2. The USB port on the PC.
(You can try a different USB port on the PC if not already tried).
3. The USB port on the printer.
If all steps do not provide a solution, please contact HP support for repair or replacement
options available for you.
HP support phone contact is 1-800-474-6836.
If you live outside the US/Canada Region, please click the link below to get the support number for your region.
http://www.hp.com/cgi-bin/hpsupport/index.pl
I hope this helps!
Thanks for choosing the HP Support Forums.