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Apple's top-of-the-line smartphone for 2020. Announced on October 13th and released November 13th, the iPhone 12 Pro Max sports a 6.7" OLED display, a triple rear camera system with LiDAR, and 5G connectivity. Successor to the iPhone 11 Pro Max.

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Face ID and screen brightness dimmed! Ambient light sensor replacement

Solved! I don’t have a simple solution but try leaving it in rice for a week or two.

In my case it was sunscreen residue that came inside the headphone speaker, so i had to pour alcohol inside multiple times (be careful and don’t try this unless you’ve lost hope) aswell as drying it in rice for weeks

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!

Answer this question I have this problem too

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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.

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This worked for me, too! Thank you!

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This works as well! I popped the wire for the face id and sensor during a screen replacement and needed a temporary fix until the replacement part arrived. Thanks!!

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It worked! Changing display zoom setting fixed the abrupt dim problem. I can't thank you enough.

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worked for me!!!! tysm!!!!

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You are my savior, thank you so much. Face ID and Auto brightness not working can live with it.

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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.

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Try resetting the iPhone and updating it from a Mac. I think they released an update that fixes dark screens with broken ambient sensors. This worked for me.

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Try a screen replacement from Apple's self-service repair program, it is the only way you can get Face ID back yourself.

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This is a common issue on this serie, mosty happen after water damage but can be also only from small raining etc. The light sensor flex get oxidacion and its disabled. Typic symptopms is device boot with normal brightness and instantly when boot on home screen the brightness come down. Easy way to fix is replace the sensor flex - you will lose face id and portrait mode on selfie camera, but brightnes will be normal again. Or you can solder the original sensors (without mic to another flex, will save the face id and portrait. When is the sensor self damage can can restore the original value from device and Programmed for example with JC Programmer. But 95% sensor self is ok. You can also try clean the flex with 90%+ alkohol or reflow with some good flux on 220°C, sometimes the flux remove oxidacion.

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This is useful to know, but seeing as this seems to be a common issue, why is Apple not taking accountability for a flawed product? My iPhone 12 Pro Max has just started doing this as as usual, it is 7 months past its warranty date.

I don't see why Apple customers should be paying a penny or spending their own time trying to fix things that Apple has not made properly.

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Problem is, there must be somehow hole to the ear speaker and mic sound can flow there. Most time is this hole only the one way for water go in the phone. And the sensor flex is first component what can be easy damage.

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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.

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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...

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I got it diagnosed by apple who said the light amber sensor and the magnetometer are damaged. They said it was probably caused by water or possibly moisture. I recommend you start with getting yours looked at (you can do it online using apple care app)

I then left it for repair in Mediamarkt and they are currently looking at it. They said it's most likely not recoverable but since i had insurance that covers it i only will have to pay a small amount to get a new one.

Did you get your replacement screen from Apple and do their screens includes new sensors or did you have to move the sensors to the new screen?

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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:)

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Did you find problem ? I had same one whit my Iphone 12.

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I think that is hardware issue. Most of that cases happens after water or moister on Front ear-speaker flex have ALS,Proxymity senser that have imp role on face id too.You have to swap the ALS to another working flex.I also face same issues and fixed on 12 pro max you can check yours like that.

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alan.bakr22 will be eternally grateful.
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