I haven't done anything to the phone, perhaps I pressed something without realizing it. But it vibrates, and does not ring. What's going on?
That happened to me, an when I checked it out, somehow I had turned down the ringer/alert volume.... so you may want to check that...
Loving life with my iPhone 4!!! Jailbreak my iPhone? Nope.. no way, no how!
New to iPhones, April 2011
Check the silver button on the side of phone, top left, you may have put it on silent.
Mine was exactly the same, thanks. You would think there was an icon for silent on the screen to remind you.