Chosen Solution
My iPhone screen suddenly went dark which I initially thought was just battery juice running out. However, I noticed it actually still was on while using it in a darker room. I could barley see anything so I tried to restart it. When booting up, it did light up normally but it dropped brightness immediately after. Also, An error message ”Unable to start up Face ID” appeared. i tried restoring the phone with iTunes and stopped auto brightness and Truetone from settings, without any improvements. I believe this has to do with the ambient light sensor, because the problem doesn’t seem to be a software issue and it’s affecting screen auto brightness function and Face ID. I have experience replacing bad batteries and broken iPhone screens but never had to change a sensor component. I read that changing them will lead to iPhone not recognising the new component and losing Face ID. I also read about this recognition problem being solved back when apple released IOS 12. If not, is it possible to reprogram the new sensor? Also, where can I buy this part from? P.S: Apple fixes it free of charge for apple care and warranty holders but I don’t have that option so it’s going to be a pricey fix with apple. I would rather do it myself if possible. Thanks in advance!
I had this same issue and tried everything I read online to fix it with no luck. Then I was messing with some settings and tried the display zoom setting and for some reason that worked. I just put it back to standard and was able to control by brightness again. unfortunately it does not fix the face id problem.
If you did a factory reset and then disabled auto brightness but the problem persists then the problem isn’t in software and isn’t with the ambient light sensor since disabling auto brightness would have effectively ignored or overridden a bad ALS. You have a bad display and/or a bad logic board.
Hello Alen. You would be correct, the brightness and Face ID failure are due to replacing them, Apple forced them to not work if they are non genuine and not paired, unfortunately I don’t know of any device that can re-pair the parts. The only thing really is too update it and hope that Apple has fixed it. I hope your phone will be able to be fixed.
Try a screen replacement from Apple’s self-service repair program, it is the only way you can get Face ID back yourself.
I had the same problem. I changed the screen and it didn’t work. Is there any other solution? They told me on the mac store that if the change of screen didn’t solve it, I should buy a new device…
Hi! I had this problem too. So i pressed volume up button, release it, then did the same with the volume down one, then pressed the side button and hold it until it shows me the slide thing on screen. You need to slide and close your phone.Then waited 5 sec, started it and it crashed,did the whole thing again and it worked:)
Did you find problem ? I had same one whit my Iphone 12.
