I have iPhone 7 plus with Sprint. I repaired the LCD recently and notice this issue happening right after. The phone shuts off and then restart when I receive a call or use face-time. The rest of the phone works: camera , sound, texting, touch screen, wifi, etc. I'm thinking I might of damage the proximity sensor when I was removing the ribbon since I misplaced my tweezer. Anyone know how to test this out before I buy the new parts to replace it. FYI: Making and accepting phone call work when using a bluetooth headset.