Hi, this has just happened to my phone and like yours it has not been dropped and has no water damage. Did you ever find out the cause or a way to fix it or did it end up being a hardware issue?Thanks.
Applebatman
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution