Fingerprint sensor issue - Xiaomi Poco F2 Pro (Redmi K30 Pro) Questions & Ans

A bit of a strange issue. The fingerprint sensor has been working 100% without issue since getting the phone.
I let the kids use my phone for an hour to watch cartoons. After that it started not recognising my finger. I cleaned the glass, removed the case, re created the fingerprint profiles. I made a mistake and tried an OTA update, which then had to fully reset the phone, but that's another issue.
I am using a tempered glass protector. I took it off for 1 day to see if that made a difference and not really. Even being extremely careful after 1 day there were tiny scratches on the screen.
Wondering if anyone else has had an issue like this. I did reload it with the latest Miui 12 stable, but made no difference. Not sure if the kids were pressing it constantly, but no signs of damage.
It will vibrate and attempt to recognise my finger, but just fails. Then the next time it may work, but intermittent and really annoying.
I have found that it seems to work better when out of a case for some reason. Maybe the sides of the case resting on the glass.
Overall I think this is a great phone. Shame about no development happening. As I use it debloated with MicroG it means I can't do ota updates.
I'm considering getting a Galaxy, Oneplus or Pixel phone. Until the possibility of more development happens if ever

We've had ours for about 3-4 days now and I have found the FPS to be crap out-of-the-box. Exactly the same issues as you, and with just the default screen protector on it. Sometimes it works fine at first attempt, at other times I have no choice but to enter the PIN to unlock.

I made the mistake of letting my kids use the phone again a few days ago. After that the fingerprint sensor would sometimes not be detected. The phone randomly won't switch on and have to hold down power for about a minute then it turns on. Very annoying, but doesn't happen all the time. Did it almost all weekend, then today it's working almost fine.
Did test in TWRP and didn't have the same issue. So making me think it's either software or fingerprint sensor related, causing the issue.
Still think the phone is great and there's not really another phone on the market I'd prefer at the moment, just need some custom rom support. A work friend has a Note 8 and his will be 50% battery while this is still about 85% or so

Same
birleytweet said:
A bit of a strange issue. The fingerprint sensor has been working 100% without issue since getting the phone.
I let the kids use my phone for an hour to watch cartoons. After that it started not recognising my finger. I cleaned the glass, removed the case, re created the fingerprint profiles. I made a mistake and tried an OTA update, which then had to fully reset the phone, but that's another issue.
I am using a tempered glass protector. I took it off for 1 day to see if that made a difference and not really. Even being extremely careful after 1 day there were tiny scratches on the screen.
Wondering if anyone else has had an issue like this. I did reload it with the latest Miui 12 stable, but made no difference. Not sure if the kids were pressing it constantly, but no signs of damage.
It will vibrate and attempt to recognise my finger, but just fails. Then the next time it may work, but intermittent and really annoying.
I have found that it seems to work better when out of a case for some reason. Maybe the sides of the case resting on the glass.
Overall I think this is a great phone. Shame about no development happening. As I use it debloated with MicroG it means I can't do ota updates.
I'm considering getting a Galaxy, Oneplus or Pixel phone. Until the possibility of more development happens if ever
Click to expand...
Click to collapse
I have the same issue since I got the phone, the fingerprint sensor is ****, I opted to unlock it via bluetooth by recognizing my smartwatch.

Hydrate or moisturize your fingers/thumbs
Much faster accuracy unlock speed

Try to Change the Glass Protector

Your using alcohol based hand sanitizer, these remove moisture from the hands making them dry. Just put some lotion you'll have much better response.

What game were your children playing on phone?
Have you looked at their fingers?
I don't like on screen fingerprint sensors. Maybe too much pressure leads to an issue.
---------- Post added at 12:29 ---------- Previous post was at 12:22 ----------
Potterified said:
We've had ours for about 3-4 days now and I have found the FPS to be crap out-of-the-box. Exactly the same issues as you, and with just the default screen protector on it. Sometimes it works fine at first attempt, at other times I have no choice but to enter the PIN to unlock.
Click to expand...
Click to collapse
Peel off the screen protector, it is bull***t.
Also, I remember to have activated the "show touches" option on developer settings. It was almost unable to recognise fingerprint. Deactivated again.
Hardware fingerprint sensor is always better. :crying:

Related

[Q] Should I use stock when I take this for repair?

For a few months my phone has had a problem where the screen will take control of itself or become unresponsive, it's not the phone being slow, because hardware keys respond perfectly. Scrubbing the screen with a Lysol wipe helps sometimes, but I'd rather just have the problem taken care of (it seems like it's caused by fingerprints on the screen, which isn't a problem on any of my friends' SKs and initially wasn't on mine either).
Anyway, when I take my SK to T-Mo, should I flash a ROM that at least looks stock for warranty purposes or will they not care?
If I do need to go to stock, how would I go about doing that? As far as I remember, I've never taken a backup in recovery and never ODIN'ed (stupid, I know), so I've no idea what to do. I can flash ROMs perfectly fine, but going back to stock is a mind-boggler for me (disabling Voodoo, etc).
Thanks
Mine always does this.
1. The optical trackpad detects the sunlight, strong indoor lights, etc, as movement and causes spurious scrolling.
2. Water on the screen or a finger just outside the boarder of the screen causes the touchscreen to get confused and either not respond or move on its own.
3. The touchscreen driver is prone to crashing. About half the times I want to answer a call or something, I need to toggle the screen off and on with the power button before it'll work.
None of this is because the hardware has broken. 1 is due to a bad design, 2 is inherent to touchscreens of this type, and 3 is just bad programming.
Ha! I have to do #3 all the time. Glad to know it's not just me. Ridiculous.
Also FYI, #1 never happens to me. I see people here curse that damn sensor all the time, but I have never had mine move randomly in sunlight, and it generally works pretty well for me as arrow-keys.
I also do #3 all the time, and have had problems with the optical trackpad in the past (I've since disabled it).
What the problem appeared to be was that my fingers are oily or something, explaining why wiping the screen excessively was useful. I passed on taking it to the T-Mobile store and instead ordered screen protectors from Amazon. No problems since I applied one.
Has anyone else encountered this, or is this a unique problem? I got through nearly a year without having this problem, so maybe something went wonky in the screen. Anyway, problem fixed
DJTiCTAK said:
I also do #3 all the time, and have had problems with the optical trackpad in the past (I've since disabled it).
What the problem appeared to be was that my fingers are oily or something, explaining why wiping the screen excessively was useful. I passed on taking it to the T-Mobile store and instead ordered screen protectors from Amazon. No problems since I applied one.
Has anyone else encountered this, or is this a unique problem? I got through nearly a year without having this problem, so maybe something went wonky in the screen. Anyway, problem fixed
Click to expand...
Click to collapse
Happens all the time to my sidekick. Screen protectors did work tho
Sent from my SGH-T839 using Tapatalk 2

Proximity Sensor intermittent

First time poster, though been a regular lurker.
It seems I have a slightly dodgy proximity sensor. Have checked with one of the proximity sensor apps and while the sensor detects if I have my hand over it, it is very unreliable when I take my hand off. It can take from anywhere from 1 to 30 seconds or sometimes never.
While ive been through other threads where people have a completely failed sensor, does anyone have this intermittent problem. Also is this a hardware or software issue.
Im currently htc-dev unlocked running Pacman v15.0.
Out there is a tool for recalibrating the sensor, but you would need to be S-OFF I think and it's done with a service tool (a special PG88DIAG.nbh)
Let me know if you are willing to try it, but it is VERY dangerous if you do the wrong things.
I had the exact problem from the very beginning. Got a phone and the very next day had a screen protector applied. For a few days proximity sensor created problems. The screen would go black when the call started, but until the call did not end, there was no way to bring the screen back. So, I used an app just like yourself to check and saw the same thing happening. Ultimately read extensively and realised it was due to screen protector. Took a scissor and cut off the protector above the sensor. A few months later when I had a new protector (of a different company) applied the same problem reappeared, so I had to cut it off from the top. Except that this time around I was sort of expecting it. I hope this help! :fingers-crossed:
I had the same problem and it continued no matter whether i remove the protector or cut the portion....im unable to most awesome ROM's.......only n sense 4.0 im able to re turn on the screen using power button.if there a way to completely disable this turn off during calls irrespective of the ROM its highly appreciated......
Looking forward for the solution
Jann F said:
Out there is a tool for recalibrating the sensor, but you would need to be S-OFF I think and it's done with a service tool (a special PG88DIAG.nbh)
Let me know if you are willing to try it, but it is VERY dangerous if you do the wrong things.
Click to expand...
Click to collapse
An update to my situation.. I ordered a new proximity sensor on e-bay and have replaced the same on my phone now. While I was at it, I cleaned up the window as it was pretty grimy and could have been the source of trouble. Also cleaned up the contacts with Isopropyl alcohol. End result.. Im still having the same problem!!
Im pretty sure now that its not a hardware problem and has to do with the calibration. What I have noticed that the sensor works fine in bright sunlight but not when there is less light around. Also am not using a screen guard!
Would it be possible to guide me to the right tools to recalibrate please?
Sorry, I haven't done this myself, but I'll search a bit how it's done by HTC.
They are using a special holding station where the devices are calibrated.

Just an FYI: Check your fingerprint sensor!

I just discovered a very thin piece of protective plastic over my fingerprint sensor that really wasn't noticeable unless you scratch it with a fingernail. Once this plastic is removed, your sensor will read your fingerprints so much better.
Just be sure to check for this plastic. If you already knew about it, then please ignore this message.
Sent from my LG-H910 using Tapatalk
I had seen reviews before my phone arrived, all mentioned it but its on there really good and could see how some people could miss it.
I leave it on, still works perfect, FYI the camera also has a protector.
LOL! every device with fingerprint in the back brings a plastic screen. I left it on when i bought my LG V20, It reduces the chances for it to get scratched. Although it has been proven that fingerprint still working even after scratched
Both Google Play and my banking app refused to recognize my fingerprints with the plastic on. They'd constantly disable fingerprint recognition after several failed attempts. Now, without the plastic, they work 100% of the time, So if anyone is having issues, they should remove the plastic. Just saying.
Sent from my LG-H910 using Tapatalk
joseguillen1994 said:
LOL! every device with fingerprint in the back brings a plastic screen. I left it on when i bought my LG V20, It reduces the chances for it to get scratched. Although it has been proven that fingerprint still working even after scratched
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Click to collapse
My Note7 and Note 4 didn't have any plastic. They weren't the same type of reader as this phone though.
Sent from my LG-H910 using Tapatalk
spexwood said:
My Note7 and Note 4 didn't have any plastic. They weren't the same type of reader as this phone though.
Sent from my LG-H910 using Tapatalk
Click to expand...
Click to collapse
I said in the back hahaha. Also, samsung is not know to be a device that put that type of plastic in their home button. (talking from experience buying the galaxy s, s2/3/4/5/6 note note 2/3/4)
joseguillen1994 said:
I said in the back hahaha. Also, samsung is not know to be a device that put that type of plastic in their home button. (talking from experience buying the galaxy s, s2/3/4/5/6 note note 2/3/4)
Click to expand...
Click to collapse
"In the back" didn't pop out at me for some reason. Sorry about that. LOL
My intention of my reply though was mainly what you just said: Samsung usually doesn't put plastic on their sensors. My last 2 phones were Samsungs (LG before that, and that was before fingerprint sensors were ever thought up), so I'm not used to finding plastic on the sensors.
I swear though, this V20 is surprising me several times a day. Sometimes good, sometimes bad. Having fingerprint sensor issues and then finding and removing the plastic and discovering that all the issues have gone away is just one of these surprises.
spexwood said:
"In the back" didn't pop out at me for some reason. Sorry about that. LOL
My intention of my reply though was mainly what you just said: Samsung usually doesn't put plastic on their sensors. My last 2 phones were Samsungs (LG before that, and that was before fingerprint sensors were ever thought up), so I'm not used to finding plastic on the sensors.
I swear though, this V20 is surprising me several times a day. Sometimes good, sometimes bad. Having fingerprint sensor issues and then finding and removing the plastic and discovering that all the issues have gone away is just one of these surprises.
Click to expand...
Click to collapse
Yeah i had a surprise today, it rebooted by itself (although it does reboot fast i mean literally, 25 second to turn off, then on, then totally initiate to the homescreen) but well, im going to wait 3 more days to see if it was because of bluetooth compatibility issues with my car old bluetooth fm transmitter or if it was because the phone is defective. If it seems like it is defective, i got a green light to go and exchange it already through the phone,
joseguillen1994 said:
Yeah i had a surprise today, it rebooted by itself (although it does reboot fast i mean literally, 25 second to turn off, then on, then totally initiate to the homescreen) but well, im going to wait 3 more days to see if it was because of bluetooth compatibility issues with my car old bluetooth fm transmitter or if it was because the phone is defective. If it seems like it is defective, i got a green light to go and exchange it already through the phone,
Click to expand...
Click to collapse
When I had the LG G Pro, I got one that had a bad CPU in it. It randomly rebooted, got really warm in my pocket randomly, and never entered deep sleep. I had to get it replaced because of that. Just keep an eye out for these symptoms.
It could just be a bad battery too. If so, your battery life won't be great, or the level will skip (goes straight from like 50% to 20% instantly). It could also cause a reboot too.
In any case, since you're still within your 14 days, it'd be best to just replace it if it turns out to be defective. :good:
spexwood said:
When I had the LG G Pro, I got one that had a bad CPU in it. It randomly rebooted, got really warm in my pocket randomly, and never entered deep sleep. I had to get it replaced because of that. Just keep an eye out for these symptoms.
It could just be a bad battery too. If so, your battery life won't be great, or the level will skip (goes straight from like 50% to 20% instantly). It could also cause a reboot too.
In any case, since you're still within your 14 days, it'd be best to just replace it if it turns out to be defective. :good:
Click to expand...
Click to collapse
yeah, that's the thing, the exchange can only happen if they conclude that the device is indeed defective. So, i will wait for 3 days and see what happens, if it happens again, it s an immediate replacement, and it will be a battle inside the store if they say no
Thank you!!!
spexwood said:
When I had the LG G Pro, I got one that had a bad CPU in it. It randomly rebooted, got really warm in my pocket randomly, and never entered deep sleep. I had to get it replaced because of that. Just keep an eye out for these symptoms.
It could just be a bad battery too. If so, your battery life won't be great, or the level will skip (goes straight from like 50% to 20% instantly). It could also cause a reboot too.
In any case, since you're still within your 14 days, it'd be best to just replace it if it turns out to be defective. :good:
Click to expand...
Click to collapse
This is exactly what has been going on with my V20, even the battery issue. I took it back to a T-Mo store and they did a warranty replacement no questions asked. Now just waiting for the new to come in. Hopefully this doesn't occur on the new one.
How does the sensor react to a wet finger? Is it still as accurate as normal?

Pixel randomly locks while in use, even in safe mode.

A few weeks after I got my Pixel I started experiencing random screen locks while I'm holding and using the phone.
I have it set to Auto lock after 1 minute of activity but this can happen sometimes immediately after unlocking with the finger print scanner. Ive only noticed it happening while on my hour train commute but that could just be because that's where I'm using it the most consistently.
I talked to Google support via chat and they suggested booting into safe mode to see if it's a third party app causing the issue. Ive currently been using safe mode for an hour and it has happened but only once when it first rebooted.
Has anyone else experienced this? I've contacted Google support again and will update if they find anything.
Thanks
I have experienced this several times. I can't pinpoint what's causing it. I'm just glad someone else is seeing this happen as well. Hopefully someone gets to the bottom of it.
I use an app "Always On" which has a "timeout" feature.
The app uses AMOLED ambient display to put a clock and notifications on the screen.
I use it when going to bed or at night. The timeout feature uses Device Administrator access and causes the screen to go fully off after a while. Sometimes the app causes the Devices Administrator requires password "error," definitely.
I will test more and report, but earlier in week I noticed screen go off as you describe, as I've noticed now and again too, and I realized it was maybe exactly 3 hours since I freshly set a 3 hr timeout in Always On. At that point I was using my phone when the device locked.
Hmm.
Sent from my sailfish using XDA Labs
wilsonic said:
A few weeks after I got my Pixel I started experiencing random screen locks while I'm holding and using the phone.
I have it set to Auto lock after 1 minute of activity but this can happen sometimes immediately after unlocking with the finger print scanner. Ive only noticed it happening while on my hour train commute but that could just be because that's where I'm using it the most consistently.
I talked to Google support via chat and they suggested booting into safe mode to see if it's a third party app causing the issue. Ive currently been using safe mode for an hour and it has happened but only once when it first rebooted.
Has anyone else experienced this? I've contacted Google support again and will update if they find anything.
Thanks
Click to expand...
Click to collapse
Maybe a magnet causing interference? http://www.androidheadlines.com/2016/11/the-google-pixel-and-pixel-xls-screens-react-to-magnets.html
tejasm1 said:
Maybe a magnet causing interference?
Click to expand...
Click to collapse
OMG you just blew my mind. This is definitely what it is. When I'm sitting on the train I have my satchel on my lap which has magnetic clasps. I'll remember to keep it away from there in future. THANK YOU SO MUCH! :good:
I know this is an old thready but this blew my mind too! I think my juul is causing it, as it has a magnet on the end to snap to the charger. Never would've put two and two together. Thank you!
P4xl - Same random screen locking symptoms, NOT MAGNET related.
All of the responses in this describe the symptoms of the problem I have with my Pixel4xl, but not the description of the cause.
I most DEFINITELY do not have any magnets within any proximity to my phone.
It only has an Otterbox case, and will often lock when being actively used, while behind held at least 6" from any other object (except my hands).
Is anyone else experiencing this (non-magnet related issue)?
djdole said:
All of the responses in this describe the symptoms of the problem I have with my Pixel4xl, but not the description of the cause.
I most DEFINITELY do not have any magnets within any proximity to my phone.
It only has an Otterbox case, and will often lock when being actively used, while behind held at least 6" from any other object (except my hands).
Is anyone else experiencing this (non-magnet related issue)?
Click to expand...
Click to collapse
Yes I have the same issue where the phone locks itself randomly on 4XL. No idea what's going on I have a fabric case... Very annoying it happens all the time
I also have the same issue on the Pixel 4. No case, I'm sitting on my couch, no magnet within 6 feet, no electronics other than a remote control, yet my phone just sometimes locks.
Yes I'm facing this issue on my Pixel 2 as well, and no magnets near me!! Can someone Please help?
Hey guys make sure your buttons arent stuck to the frame
It's happening to me too on my pixel 4 xl. Did anyone determine a cause?
Same issue, no case on it or any magnet nearby. It's super annoying.
I had the same issue on my Pixel XL. Didn't think twice about it since it was an older phone, probably a bug with new os/old phone. But i just upgraded to the Pixel 4a and the same thing is happening! Is it related to smart unlock? The weather? Mars in retrograde?
djared704 said:
Hey guys make sure your buttons arent stuck to the frame
Click to expand...
Click to collapse
Definitely not the cause for me.
In my Otterbox case, when pressed, the volume buttons cause the volume interface to appear (which isn't happening),
and the power button has a distinct click when pressed (and when held, activates the nfc card payment interface).
A good guess, but unfortunately isn't the cause, in my situation. ??

Mate 9 Calibration

Has an had any issues with screen calibration? Sometimes when I click on the screen it presses to the left of it. When I'm in the recents screen for my apps, it sometimes swipes away instead of selecting it, and I'm unable to consistently unlock the phone while it is charging. (Works like once in every 5 times) however, I'm on sure if that one is related.
Anyone have any ideas?
Which firmware are you on? I remember older firmwares were having a bit of a touch sensitivity isues.
Sammath said:
Which firmware are you on? I remember older firmwares were having a bit of a touch sensitivity isues.
Click to expand...
Click to collapse
I'm on MHA-L29C567B183. US version of the phone. Stock
Did you install a screen protector? Could be the reason for sensitivity issues. If not, I don't know. Maybe a factory reset Will help?
Sammath said:
Did you install a screen protector? Could be the reason for sensitivity issues. If not, I don't know. Maybe a factory reset Will help?
Click to expand...
Click to collapse
I removed the screen protector when I purchased it. I could do a factoru reset and see how it goes. Hopefully it's software related and not hardware related.
I do hope so as well then. I do have to say that the factory installed screen protector doesn't do this screen justice.
Sammath said:
I do hope so as well then. I do have to say that the factory installed screen protector doesn't do this screen justice.
Click to expand...
Click to collapse
I thought it was for protecting it in the box?
Mine had a lot of air bubbles in it so removed it right away.
My charger still has the plastic on it though xD
ante0 said:
I thought it was for protecting it in the box?
Mine had a lot of air bubbles in it so removed it right away.
My charger still has the plastic on it though xD
Click to expand...
Click to collapse
Lol, no, this phone comes with a screen protector pre installed .
The touch sensitity is definitely off a little. I have to swipe the notification bar sometimes twice for it to come down. I also get some missed taps but it's infrequent enough that it isn't a problem for me. I heard they started fixing touch latency and optimization in 5.1. Don't know if we will ever see it.
If you are not using the stock charger weird things can happen.
Alrighty update: Factory settings still yields the same results. It's not frequent enough to make me go crazy, but it's still roughly the same. I guess my real pet peeve is when I need to go to the app manager to return to an open app and it just closes out. I've lost a lot of information that way like recipes when cooking and etc.
What I really don't understand is the fingerprint sensor not working while it's charging. It doesn't matter what charger I use. It just doesn't respond most of the time (Sometimes it unlocks like it's suppose to)
Im using Quick Charger from SS and I have this problem too. It's nice to know this is a common issue, not only me. I dont have any issues with fingerprint when charging, just notice when the battery between 5-60% it's insensitive for me (maybe quick charge is working strongly in this range), "insensitive" here means when you press and hold any things on the screen, it'll "tap" it and open it instead, all pressing or sliding or zooming actions are normal, just dragging has issue. When the battery is 70% and above, it becomes normal and no more insensitive touch. Just that so I think I can bear this thing.

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