Thank you for using Apple Support Communities. It's my understanding that the camera on your iPhone 7 Plus shows a black screen and the flashlight doesn't work. I use my camera almost daily so I can surely understand your concern. Please review the steps and information below:
Get help with the camera on your iPhone, iPad, or iPod touch
You see a closed lens or black screen
If you see a closed lens or black screen when you open the Camera app, try these steps:
- Make sure that there’s nothing blocking the camera lens. If you’re using a case, try removing it.
- Force the app to close, then open the Camera app again.
- Restart your device, then open the Camera app again.
- If your device has a front and rear camera, try both cameras by tapping . If you see the closed lens or black screen on only one camera, take your device to an Apple Retail Store or Authorized Service Provider for more help.
Your flash isn't working
If you take extended video with the flash on, or you’re using the device in a very warm environment, you might see a message that says the flash is disabled. The message remains until your device cools down.