Develop Bugs

[Q] Fingerprint sensor pressed without touching?!

Hi Guys,
I got a really strange and annoying issue. Since a while my it seems like the homebutton is pressed by itself. With the fingerprint recognized turned on this results in a wake up of the phone! Strangely my (correct) fingerprint is not necessary and the phone is unlocked.
I already cleaned the sensor with (medical) alcohol and restored default setting. I'm of course worried about the hardware/sensor that is broken but of course hope that you guys recognize this problem and maybe have an solution
Thanks by advanced

Ambient issue after being in pocket

I just got my Pixel yesterday and started having this issue, so I thought I'd check in with the fine folks at XDA.
I had Ambient display set to "always on" and "double-tap to check phone" set to on. After a while of being in my pocket, the screen will be black when I pull it out. Double-tap to wake does not work and it never comes on. The only way I can wake the phone after that is the fingerprint reader or power button (which I never use on my Android phones). It seems like Ambient display is going to sleep due to the proximity sensor and then just not waking up.
I changed it to lift to wake and the problem is mostly gone, but I would rather have ambient display on all the time. This is brand new out of the box. It's not rooted or anything. I haven't even unlocked the bootloader.
My OnePlus 6t was doing something similar (to a lesser degree) and it drove me crazy. This is something I need to work consistently. I expect to take my phone out of my pocket, glance at the AOD, and then tap twice to wake it and interact with the lockscreen. That's how I use all of my phones.
I just wanted to see if anyone else is having the issue. I haven't wiped it because, really, it's been doing this since I took it out of the box (new). And I have seen some other scattered reports online. Rebooting also did not resolve it.

This has happened to me a couple of times. Quite annoying.

Yeah, I have this problem too. Another bug...

Yep. Happens to me fairly frequently

It started happening to me recently too.

Thanks for the confirmation, guys. Glad I'm not crazy. This may actually be a deal-breaker for me, though. I'm pretty anal about the consistency of tap-to-wake on my devices.

Always on display "flickering" when activated (on tap)

Hey everyone!
As the title say i'm facing a issue with my always on display.
I'll try to make it as simple as possible:
When I set the always on display to be always active it works flawlessly.
When I set the always on display to activate on tap (and last for 10 seconds according to the settings) it appears for roughly 3 seconds and then disappears for 3-4 and reappears flickering for 2-3 times sometimes showing the desktop wallpaper between each flicker.
Did anyone experience the same issue?
What I did to try and fix it was:
- tested both on battery and while charging
- factory reseted and then restored backup (which was stupid, that lead me to the second point)
- start in safe mode (to check whether it was an app causing troubles) but no such luck, problem still occurs.
- uninstalled "nice lock" apps
- changed some settings under the always on display tab
- cleared cache of the always on app
What you should know:
- I'm running android 9, not rooted and have nova launcher as default home
- After I factory reseted the phone I wanted to stop always on display from updating to test whether it was a new version issue but I forgot and didn't make it in time so I'm currently running the latest version
Does anyone have any idea as of why it's behaving like this?
edit: just wanna be a little more clear, flickering is not meant like a lightbulb it's more something like it turns off and back on after a delay (I'm sorry english is not my native language I can't really explain it any better)

Frans1897 said:
Hey everyone!
As the title say i'm facing a issue with my always on display.
I'll try to make it as simple as possible:
When I set the always on display to be always active it works flawlessly.
When I set the always on display to activate on tap (and last for 10 seconds according to the settings) it appears for roughly 3 seconds and then disappears for 3-4 and reappears flickering for 2-3 times sometimes showing the desktop wallpaper between each flicker.
Did anyone experience the same issue?
What I did to try and fix it was:
- tested both on battery and while charging
- factory reseted and then restored backup (which was stupid, that lead me to the second point)
- start in safe mode (to check whether it was an app causing troubles) but no such luck, problem still occurs.
- uninstalled "nice lock" apps
- changed some settings under the always on display tab
- cleared cache of the always on app
What you should know:
- I'm running android 9, not rooted and have nova launcher as default home
- After I factory reseted the phone I wanted to stop always on display from updating to test whether it was a new version issue but I forgot and didn't make it in time so I'm currently running the latest version
Does anyone have any idea as of why it's behaving like this?
edit: just wanna be a little more clear, flickering is not meant like a lightbulb it's more something like it turns off and back on after a delay (I'm sorry english is not my native language I can't really explain it any better)
Click to expand...
Click to collapse
i also experience the same.
this phone has many strange bugs.
when i restart my A70, tap to show always on display works for me for 2-3 times.
after 2-3 times working correctly, the bug starts.
after i tap the screen, it shows AOD for 2 seconds. then turns the screen off and then at the end of the 10th second, screen just flashes itself for the last time and turns off completely.
i think it is related to the fingerprint scanner.
because after i registered my fingerprints and turned on unlocking the screen by the FP reader, this bug ends.
after i tap the screen it shows both the clock and fingerprint icon at the bottom of the screen.
after 2 seconds fingerprint icon disappears. and the clock is continued to be shown until the end of 10th second.
but there is a minor issue, when the fingerprint icon disappears, the AOD screen brightness changes. dims or brighter slightly.
can you please try tap to show AOD, by enabling the fingerprint unlocking?
samsung ?

xprzs said:
i also experience the same.
this phone has many strange bugs.
when i restart my A70, tap to show always on display works for me for 2-3 times.
after 2-3 times working correctly, the bug starts.
after i tap the screen, it shows AOD for 2 seconds. then turns the screen off and then at the end of the 10th second, screen just flashes itself for the last time and turns off completely.
i think it is related to the fingerprint scanner.
because after i registered my fingerprints and turned on unlocking the screen by the FP reader, this bug ends.
after i tap the screen it shows both the clock and fingerprint icon at the bottom of the screen.
after 2 seconds fingerprint icon disappears. and the clock is continued to be shown until the end of 10th second.
but there is a minor issue, when the fingerprint icon disappears, the AOD screen brightness changes. dims or brighter slightly.
can you please try tap to show AOD, by enabling the fingerprint unlocking?
samsung ?
Click to expand...
Click to collapse
Hey! Thanks for the answer, I can confirm we have the exact same issue. I also have the same brightness issue you described
Anyway, I have always used fingerprint unlock though so I don't know what to answer you.. I only recently noticed the weird behavior. I did a couple things to test and I found out that enabling the "fingerprint" icon showing in the always on display seems to "fix" the issue of the flicker but not the one of the brightness change (after enabling it i've yet to see the problem occur), you should try it and let me know if you see any improvement. It's probably on samsung's end though and hopefully we get it fixed with android 10 or earlier
I'll take this chance to ask you another question; two weeks ago I received a software update and ever since that day I noticed my battery to be lasting waaaay less than it used to, did you update your phone as well? Did you notice a battery drain?

I have the issue both of you talking about.

hello, I had this same issue and what I did was turn the phone off, and booting it up while pressing "Volume Up", after entering a black screen with many options, I selected wipe cache. It has worked without a flaw since then. There's lots of bugs with this phone. I recently had a problem where the USB port will detect a device and "plugged and unplugged" it, making my phone unable to dim. Thankfully I was helpful.

Fingerprint problems, but only on MIUI roms?

Hi,
As the title says, I'm experiencing some problems related to the fingerprint sensor, specially when I try to wake the device as I have to put my finger in the sensor twice because the phone doesn't recognize my fingerprint at the first try, it just vibrates, but the second time I put my finger it wakes up the phone with no problem. It feels like the sensor puts itself in deep sleep mode as it happens like 15 seconds after I turn off the screen.
The fingerprint sensor works fine when the screen is on, as I can unlock protected apps at the first try. But some apps that include their own fingerprint authorization like Paypal or my bank account app shows me an "error" as soon as they ask me for the fingerprint, like the fingerprint sensor is already in use (not sure how to explain it), but they work as soon as I put my finger on it.
Pressing the sensor for a little longer wakes the device at the first try, but I'm pretty sure that's not the normal behaviour.
Disabling the pocket mode doesn't help either.
As the title says, this only happens on every MIUI rom Iv'e tried, like Xiaomi.eu, Mi-global or Revolution OS, always made a clean flash. I've tried Havoc-OS and Pixelexperience and the fingerprint worked flawlessly, not a single problem with those roms and that's what makes me think that it's a software related problem. In fact, I'm currently using Havoc 3.0 and the fingerprint sensor is working great.
I've also tried to flash persist.img from the chinese official rom without success. And needless to say that I've cleaned the fingerprint sensor several times.
I know it's not a big deal of a problem, but it's driving me crazy. So any help would be appreciated as I really want to use MIUI instead of any other custom rom.
TL;DR: I have to use the fingerprint sensor twice to wake my device and feels like the fingerprint sensor puts itself on deep sleep mode or that it's already in use somehow. But it only happens on MIUI roms.

Touch screen problems? Maybe actually proximity sensor (which is terrible).

One of the touch screen issues I sometimes experience is when swipes are "broken" and register as shorter swipes and taps. This makes me think maybe the accidental touch protection, which is supposed to be triggered by the proximity sensor, is being triggered when it shouldn't. We all have read complaints about how the proximity sensor does not work very well.
So on a hunch, last time I had this issue (trying to swipe in gboard), I stuck my finger on the front-facing camera, and interestingly, swiping worked fine (I expected the screen to be disabled - guess that only actually is supposed to happen when you're on a call?).
Since this issue is so random it's hard to really test it. But I've had quite an experience with the proximity sensor.
I wanted the AOD to turn off when the phone is in my pocket, which is the norm on other phones I've used but for some reason Samsung does not do. So I set out figuring out how to do this in Tasker. I got a sensor test app and noticed the proximity sensor basically has two values: 0.0 and 5.0. It is very slow to respond (slower for "uncover" events) and seems to only switch to 0 if my finger is right on the camera. So I set up Tasker to turn the AOD off if the proximity sensor value is < 1, or on if it is >= 1. I also made it vibrate briefly so that I could tell when the sensor was toggling even if I couldn't see the AOD.
At first it worked fairly well. If I manually covered and uncovered the camera, the AOD would dutifully toggle (not instantaneously). But in "real life" practice, it turned out to be quite unreliable. There would be phantom proximity changes while I was using the phone or carrying it -- most interestingly, it often toggles the AOD off briefly when I pick up my phone -- but I didn't really notice any surprise vibrations while the phone was in my pocket. After a couple hours, when my living room got darker (not completely dark), the whole thing went crazy and the AOD would toggle every few seconds with the phone sitting on a table.
So I think the whole "let's ditch a dedicated proximity sensor and use other things to get the same result" is not quite mature yet. And perhaps it is buggy enough to cause one of the issues we think of as a touchscreen one.