Chosen Solution
Is there anyway to bring back the missing “auto-brightness” option after replacing an iPhone 7 Plus screen? I replaced my screen, with one from iFixit, and and while the screen, Touch ID, Camera etc work fine, I seem to now be missing the option to enable auto-brightness. This makes the phone very hard to adapt between indoor and outdoor lighting conditions without manually having to change it all day long. And leaving it at a higher brightness results in horrible battery life.
Without Apple’s Official tools, you have to keep the original screen and ALS flex cable, get a screen/ALS programmer, copy data from the original screen/ALS flex and write into new ones. This does not make the ALS color/brightness sensing accurate, because the calibration data is from another unit that has different physical properties, but it does trick the phone into bringing back the options.
I think the DFU restore suggestion fixed mine. I only did the DFU restore because of a different issue but apparently it fixed my Auto-Brightness at the same time. Thanks!!!
