[amit85]

Hi. I bought iPhone 6 one month back. It has iOS 9.2 installed in it. Since one week
I have been facing a peculiar problem. My daily routine involves a lot of field work
And travel in the city. At times I happen to visit place where the signal strength from service provider is low or negligible. When the signal is zero the iPhone goes into No service mode because of non availability of carrier's signal.
The problem is usually when I go back to place with good signal strength the phone use to display full bars in signal. But since last five days whenever the phone goes no service, it does not regain signal when I am back in area where signal strength is good.

In short the phone permanently remains in no service mode. I try to do plane mode on and off but it remains no service. It is only when I power off and then on the phone, no service goes
Off and signal comes back.
Can any one please suggest what shall I do. Thanks for help.

[Sherry_B]

Welcome to iMore!

Make a full encrypted backup of your phone. Factory reset and install iOS 9.3.1. A lot of carriers sent out a tiny update after the release of 9.3, so you should probably get that too. Then restore your phone from the backup you just made.

That should fix any wonky connection issues and get you all up to speed with both an iOS and carrier update. If you still have the issue, definitely take the phone back in to your local Apple store for either a repair or new phone, depending on your warranty.

[Ledsteplin]

You might first try Reset Network Settings.
Reset Network Settings Settings>General>Reset>Tap Reset Network Settings. You may need to enter your wifi passcode back in afterwards.