Random Screen dimming (while brightness slider stays at 100%) after A12 update

Def not fixed 2 Minutes in the Sun and I dont see a lot

Funny enough I was able to make it happen just now, with a table lamp. Was holding my phone under a table lamp (75W equivalent) and after a couple seconds the screen went darker, slider still at full brightness.
Patch level FP4.SP28.B.065.20230420 (April 5th), phone wasn’t warm.

Tried to make it happen again, didn’t succeed, so there is a part of randomness in it (or some additional condition(s) besides illumination). :thinking:

It has to be related to the brightness sensor at the top. Maybe it registers the infrared light that’s part of sunlight and then concludes the user has their face infront of the display?

I think you are confusing the ambient light sensor with the proximity sensor. And neither of them work like this. Some apps completely turn off the screen when the proximity sensor detects a near object. But that’s different than this dimming. This actually resembles the screen dimming on some OLED phones, where it’s a “feature” that helps prevent burn-in in hot conditions.

I see, that makes more sense. So it’s basically the display thermal-throttling itself?

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Apparently it swings both ways! :astonished:
Yesterday evening I was using my phone in a dimly lit room (and the screen was consequently dim too), when all of a sudden, without apparent reason, the screen’s brightness went all the way to full!
Hiding the luminosity sensor with my hand didn’t change anything, the screen remained in full brightness till I switched the phone off and went to sleep. Phone wasn’t specially hot or cold either, it just happened, and it’s definitely the first time brightness goes randomly up for me.

Thats a bit a different case, even if you feel it should not go up, the slider moved. And not as described above dimmimg without moving the slider. Might be connected, however for me a different situation and I’m not sure we should mix here several brightness issues into one topic. Better open a new one and link here.

They should have kept Android 11 and only added security updates. The Fairphone has been a real shitshow since the Android 12 update.


I absolutely agree with you. It’s really, really horrible with all the bugs. Let’s hope the beta testers help to fix them in future updates.

Hi! I have had the FP4 for a month or two now.

Overall the phone has worked well for me. There are a few quirks being in USA, but really not that significant.

The reason why I’m posting today is that I have noticed that my screen dims and then goes back to what seems to be full brightness at random occasions, what seems to be anywhere between a few hours to a day or two. I have the brightness at Max and the auto brightness setting off, and yet I noticed that the brightness toggles between two modes it seems like. When the brightness dims, the brightness indicator still shows Max. I haven’t been able to find any additional setting around this and so I wonder if this is a bug or something like it. Does anyone have any experience with this? Any thoughts?

Thank you!

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Hi, I have the same issue but no solution yet, sorry :frowning:

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You are not alone as you can see above

Sure but the thread title currently states “Random brightness decrease after A12 update”, and mine was a “random brightness increase”, so I thought this might be on topic…

If you want to limit it to the specific cases of random change without slider movement, feel free, after all you’re the boss here…

Yes and you read the topic as well before, so since when are titles perfectly reflecting the topic🤔

That might be true but it’s not really an argument against posting my specific case here either, is it. Anyway, whatever.

To get back on topic, brightness management seems utterly broken after the latest update (April 5), at least on my FP4. First of all, it takes 5-10 seconds to react to a brightness change – if it does (many times adaptative brightness simply doesn’t work at all, sometimes for a whole day), and when it does, it doesn’t chose a brightness and stay with it, it changes its mind after a while: Goes dark, then, after 5 seconds, goes even darker. Or bright, and then even brighter. Go figure. :thinking:

Still not the topic so maybe open a seperate topic.

this topic here is about a screen that dims, while the brightness stays at 100%.

Strange moves of the slider are a different story especially when this assumption is correct

@rokejulianlockhart I amended the title, if you dont agree let me know


Thanks! Hopefully this can be fixed. I believe I have seen Max brightness and it is totally sufficient (when randomly allowedl!

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i have the same issue :frowning:


If you use the smartphone for a long time, the display dims itself at some point, even though it is 100%. But there is absolutely nothing you can do about it. At some point it will work again.


I moved your posts here to not duplicate topics (the other user still need to confirm the issue is the same)