Question about HP Slate 7 VoiceTab Ultra 3900nz

Yes, I replaced the HP data pass with my own micro-sim card from Sunrise, with my old phone number.

Exactly, it is an HP datapass.
This is managed by foggmobile.eu.
In June 2015, the Salt/Orange network was automatically attracted.
But from October 2015 you have to choose Swisscom 3G.