A black screen with a white spinning wheel means iOS is working on itself. For example, an iOS update may include configuration changes, or the iPhone is trying to recover from a crash. Sometimes the iPhone just doesn’t boot iOS properly after showing this.
Why does my iPhone have a spinning circle at the top?
The spinning wheel issue means that some network activity is going on in the background, which would drain your battery power. The wheel will only show up on iPhones with Touch ID, so it wouldn’t be a problem for other Apple devices.
When I unlock my iPhone The screen goes black with loading circle?
When your iPhone crashes, you might see a black screen with a spinning circle as the system software attempts to recover itself. That can sometimes fail, however, and you’ll continue to see the same screen indefinitely. A force-restart should fix an iPhone when it gets stuck on a black screen with a loading circle.
