Ask Mac Questions and Get Answers from Experts ASAP
Hi, I'mCustomer Welcome to JustAnswer. I'm reviewing your question now, and will post back with your reply ASAP.
It is possible that the LED backlight of your iPhone 7 is failed. If this is a software issue, restoring your iPhone from will fix it :
Important : No data should be lost when restoring your iPhone, But it is recommended to make a backup
Download and install iTunes on your computer from here : http://www.apple.com/itunes/download/
Connect your iPhone 7 to your computer and open iTunes then Press and hold down both Home and Power button until your iTunes asks you to restore it. Click Restore.
Let me know the results
Has everything worked out please?
Do you still need help ?