iphone doesn't ring

Try

Reset: Hold down the Sleep/Wake button and the Home button at the same time for at least ten seconds, until the Apple logo appears. Note: You will not lose any data

Check it with your provider, voice mail is a carrier service.

My iPhone 5s will not ring whether locked or unlocked. I tried all the suggestions but it still won't ring. I used Do Not Disturb once and cannot turn it off. The choice "Only while iPhone is locked" cannot be unchecked. I am getting calls only when I check voice mail and that is too late. This seems to be an ongoing problem with Apple. I don't understand why this problem can' be fixed. It has apparently been around since iPhone 4.

I recently had the problem that my iPhone6 wouldn't ring for calls nor beep for texts. I thought I tried everything even checked the Do Not Disturb (DND) in the settings. It was off. Then I read to check the DND on the close screen.

Swipe up from close screen, make sure the DND is not lit. If lit touch it to turn off.

My settings stated that DND was off but my button was lit when I swiped up. Seems to be working fine now.

I know this is old and you've probably figured something out by now but this I did not know and my phone was doing the same thing.

I recently had the problem that my iPhone6 wouldn't ring for calls nor beep for texts in the off mode. I thought I tried everything even checked the Do Not Disturb (DND) in the settings. It was off. Then I read to check the DND on the OFF screen.

Swipe up from OFF screen, make sure the DND is not lit. If lit touch it to turn off.

My settings stated that DND was off but my button was lit when I'd swiped up on the OFF screen. Seems to be working fine now.

Edit

I tried everything suggested and nothing worked. Then I tried Settings > Sounds > and I turned OFF Vibrate on Silent. Kept ON Vibrate on Ring.

My phone rings now when its locked!