I have a 6 that is about 14 months old, so out of warranty and I did not buy Apple Care. Increasingly while not connected to wifi I get "no internet connection." Occasionally it seems to have the same issue even when connected to a good wifi router, but it is more common on the LTE connection. If I turn on airplane mode and then immediately turn it back off (my crude effort to reset the connection), it solves the problem. But that's a pain, and the problem is becoming more frequent.

Am I right to assume I probably have a bad antenna or does this point to another issue? What sort of repair cost would I expect with this?

I'm just trying to determine my best option. Thanks!

I don't know much about iPhones but it also sounds like it could be software instead. Have you tried a factory reset to see if that improves the antenna connection?

The fact that you can go to airplane mode to get it working again makes it sound software instead of hardware. If you had to bang it on the desk on the left corner 3 times then that sounds like hardware.

I had a similar issue on my iPhone 6 where it would show that I had a connection, but there no text messages would send and no webpages would open. Hard resets were the only thing that made the connection come back.

I wiped the phone fully and started clean. That did help some, although it would still happen once a week or so. The thought was I had failing hardware that caused an incompatibility with some apps I had. Finally I just upgraded to a new phone so I don't know how long that fix would have worked.

Thanks for the feedback!