It's not that simple...
Without going into detail, the most difficult GPSs to unlock that have passed through my hands are the Sony NV-U, Navigon GPS and Pioneer, specifically the Avic F700BT model.
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Regarding Navigon GPS, for example, to unlock a Navigon GPS and install iGO Primo, depending on the unlocking mode, in most cases other third-party programmes are needed, such as
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I don't know your model, I've never had one in my hands, but now I ask you a question, with this unlocking mode, have you tried to see if the iGO8 you've installed picks up satellites?