Phone won't switch to 3G or 4G, only uses 2G with any SIM [answered]

asked 2015-02-04 13:47:04 +0300

Venty
710 ●23 ●34 ●40

http://www.hackerfunk.ch/

updated 2015-02-04 13:49:03 +0300

Since a few days, my Jolla will always stay at 2G. It started after it shut down because of empty battery.

In the preferences, I can set it to prefer 4G, prefer 3G, the phone will stay on 2G all the time. This happens with any SIM card with any (swiss) network. My friend, who also owns a Jolla, and I swapped SIM cards, both from Swisscom. Promptly, my card worked at 4G in his phone, while my phone with his card stayed on 2G. I also tried Sunrise and Orange cards, to no avail. My device will not switch to 3G or 4G. And I know for sure that 3G and 4G is available both at home and at work. Also rechecked with a Samsung Galaxy S5.

I have tried switching to flight mode, rebooted the phone numerous times (when switching SIM cards) and also tried restarting the network with the Jolla utility in preferences. Nothing helped yet.

I can make phone calls and Internet over GSM/EDGE is working (though horribly slow, naturally), so the Jolla does work. Also I could switch my Jolla to 4G only using the Radio Switcher app from Openrepos, so it is not a hardware issue.

My educated guess is that something withing CSFB is going wrong here, but I have no proof for this whatsoever.

However, I'd like to fix this but other than a factory reset, I see no other solution, and I'm a bit hesitant going this way yet, so I thought I'd first ask here for any other suggestions what to do.

Thanks in advance