Recently the motherboard failed on my out of warranty S6 and as a replacement I obtained an unlocked AT & T S7.
However all is not well with this phone as under the Mobile Networks menu, the phone does not allow the selection 2g, 3g, 4g/LTE etc .
If I look under Device Info, it has the following options: WCDMA preferred, GSM only, WCDMA only,,CDMA only, CDMA auto Ev/Do only, GSM/CDMA, LTE/CDMA,LTE/GSM, LTE/GSM/CDMA, LTE only
After many trials, I found that none of these settings enables the phone to automatically select the best radio channel for either calls or the internet...except that the phone does its best to hang onto GPRS and some 4g signals only when set to WCDMA.
Any of the other settings , even if it the phone shows a strong connection,( eg. 4G) calls made to the phone simply don't connect....no ringing indication.
I am unfamilar with the impact of APN settings..but is it possible that even though the phone is unlocked, that some other settings might enable it to operate happily on Vodafone NZ's great network? Or am I in a dark space with this phone?