Same hapend to me.
Iphone 7 wifi not working after screen replacement.
Replaced iphone 7 screen and home button forgot to unplug battery phone does not turn on tried everything then i bought another screen replacement and unplugged the battery this time connected the screen and then reconnect the battery still nothing then i plugged it in and found out that the battery was dead just needed to charge.
Possible causes of the wifi being greyed out is that perhaps dirt debris has found it s way inside your device or any liquid damage can cause this.
However when your iphone 7 won t connect to wifi the problem is almost always software related and can be fixed without needing a repair.
Identifiable by the model numbers a1549 a1586 and a1589.
A greyed out wifi symbol on your iphone can indicate a possible hardware problem which will mean your device may need a logic board repair as the wifi chip is a component on the main board.
Mind you this is not the first iphone 6 lcd i replaced so i m not exactly a beginner.
Released on september 19 2014 this 4 7 screen iphone is the smaller version of the iphone 6 plus.
At this point we can t be certain whether not your iphone is broken.
Still there s a very small chance that your iphone has a hardware issue.
However now i can t connect to wifi unless i m right next to the router the antenna needs alot of signal to see any network.
Is it possible my iphone is broken.
I did everything by the book as i replaced the cracked screen and everything seemed okay after reassembly.
We know it s stressful when your iphone won t turn on after a screen replacement.
After having an issue with an iphone 7 s home button not working but the touchid on the replacement screen was working strangely enough yesterday i was being rather cautious with an iphone 7 today.
Thankfully now you know the steps you can take to fix this problem.
Thanks for reading and if you had this problem comment below and let us know how you fixed it.