I live in Tokyo and bought a new C6833 Xperia Z Ultra thru amazon.co.jp, around May 2014. It was working fine until Sep 2014, after which suddenly it will stop making / receiving calls. But the signal on the display looks normal and no error messages. If I try to make a call it would abruptly stop with a beep and when someone dials my no, they would get the message that my phone has been turned off. But the Wifi & LTE data mode works fine.
Initially I thought it was a sim card reader issue & would reinsert my sim card. For few minutes it seem to work fine and the same problem happens again. I also tried resetting my phone using phone companion, but same result. Then I tried resetting once & didn't turn on the LTE data / wifi. I was able to use it "just as a phone only" without any issues for more than 2 weeks. When I turned on the Wifi / LTE data the problem happened again. So the issue doesn't lie with the sim card reader, but probably a software issue.
I also thought I may have accidentally bought a stolen phone and checked with my carrier (docomo) whether my Phone is IMEI restricted. There was no issue and my phone is not blocked.
Does anyone else have this same kind of issue?
