Chosen Solution
Hello, I’ve started fixing iPhone 7 recently and have had issues with backlights after replacing screens. It happened multiple times. I’ve made sure the battery is unplugged at any time when I’m working on the board. Do you guys have any more suggestions on how to prevent that damage when repairing iPhone 7. Thank you Update (03/31/2017)
here is a picture of my issue
I would suggest you try a different supplier for your parts as a test. It seems like you are getting bad parts which come in batches from time to time.
1: maybe screen connection, try more time at screen and logic board connection 2: maybe the screen backlight soldering not good , try soldering one more time with soldering paste
