Why is my xperia z1 had a network problem?
Sometimes, network in my device working as usual. And then, it suddenly change it into "Emergency call only". After that, it has a network back. And then, disappear. It repeatedly every second.
Questa è una buona domanda?
Try the following.
1. Remove SIM card and reinstall, see how it performs. If still the same,
can you put the SIM card in another phone that is on the same network and see if problem is still there? This will prove whether it is network or phone.