Q: Touch ID doesn't work after iOS 7.1 Update

Thanks for the advice Mr. Finch and thank you for your 50 years in the industry. Software itself is of course not heat sensitive, but it can and does cause hardware componenets to heat up and sometimes they can get too warm, especially if some errant code keeps executing repeatedly at a high rate. Some pariticular units might be more sensitive than others and may fail to work at a higher temp and work again when they cool down.

samicircle wrote:

 

Thanks for the advice Mr. Finch and thank you for your 50 years in the industry. Software itself is of course not heat sensitive, but it can and does cause hardware componenets to heat up and sometimes they can get too warm, especially if some errant code keeps executing repeatedly at a high rate. Some pariticular units might be more sensitive than others and may fail to work at a higher temp and work again when they cool down.

Perfectly true. But it's still a hardware defect and should be treated as such. You don't want this problem to get worse over time. As all models with Touch ID are still in warranty the best course of action is to get the phone replaced with one that does not fail at higher temperatures.

For me, touch id works more reliably and faster than it did before I installed 7.1.

One tip that helped me: I hold my finger over the button for a second.

Lawrence,

I am sure you have worked with software and hardware to understand software can be used to sense temperature... I am sure this not a hardware issue, if it were it would have occured equally as much before the upgrade.

What is to say the sensor doesnt activate based on the heat emitted from the finger being on it? If this were the case and the new upgrade changed the threshold, it could potentially cause the phone to work only when it is cold. I say this because instead of putting my phone in the fridge, i have had the same luck with having my thumb being cold.

Does this make sense?

No, it doesn't make sense, because My 5S and plenty of others do not exhibit this problem. We all have the same software, so we should all have the same problem unless there are differences in the hardware. There have been a number of failures of Touch ID reported on the 5S with the same symptoms before the update, and Apple replaced those phones. Why are you so opposed to getting a new phone to replace your defective one?

I noticed the same thing...if you swipe your finger after the buzz instead of lifting it (wiping away the residual finger print?), the next touch seems to recognize reliably.  Perhaps Apple increased the sensitivity of the touch sensor in software to accommodate sensors that are less sensitive (due to manufacturing variances, which caused some people to have problems earlier?).  Seems to me  more likely than a temperature issue.

A cold sensor would be less likely to retain fingerprint oils I'd guess, right?

Can't even imagine how (if) they can fix this if true....

my phone is issued through my company and that would require me to go through a long process and the replacements are refurbished iPhones.

BUT, the strangest part is all the people that are complaining about it not working after ios 7.1 (including myself), didn't have this problem pre ios 7.1. My touchid success rate was nearly 99%, i can remember only 1 time it failed.

I will eventually will end up going to get a replacement because this is annoying and i dont care about the long process or the refurb phone. I just wanted to make you aware this can most definitely be a software induced issue.

I'm thinking this is power related. There seams to be a correlation with device being plugged in and device being cooled. Both of these "fixes" can provide a little boost to the power. In addition resetting the privacy settings reduce the number of apps pulling information from the location services reducing the load on power sources. In these cases some piece of code has caused enough of a spike in power to leave the fingerprint scanner without enough. Only the developers will be able identify why. I wonder if there is also a hardware correlation between service providers or different manufacturers for the components.

One of the main changes was to increase the accuracy of Touch ID. So making it more sensitive is a possibility.

Thank you Mr. Finch. I think it indeed is a hardware issue with my unit, related to temperature, which probably was marginal under 7.0.4, but with 7.1 the weakness was exposed... something that was on the marginak kend of the yeild. My point in cooling down the 5s for 30 secs in the freezer was to demonstrate exactly that. I did this a good 10 or 12 times... i.e. every time I left the 5s get to room temp (78F) the sensor failed and everytime I cooled it, it worked. There seems to be others out there with the same issue. I went to the Apple store and they categorized it as a heat related issue and gave me a new one. I have tried to break it the same way, but it is holding up just fine. In fact the touch id seems to work much faster, as it did on the old one too, when it was working.

it actually has more to do with proximity dectection of the finger than anything else. touch id itself is not failing per se, it is failing to detect the presence of the finger.

I find that it always work if I let the phone auto-lock. If I lock it manually, Touch ID will not respond.

I havent found a way to add more than one fingerprint after I deleted all but one.

Hi all,

So I ended up bitting the bullet and resetting my phone. I restored it using my file from the cloud, the Touch ID was still not working properly. I cooled my thumb (using ice water) and the Touch ID started working. It has been ~12 hours since then and it seems to be working fine. I am not sure if it's just taking time to adapt. My guess the Touch ID sensor is built to learn patterns. Might be worth a shot to give it time.

i thought about that and there might be some truth to it. like i said it doesnt seem to be the logic of the touch id, but instead the proximity sensor does not appear to detect your finger is on it

Same issue here. I've used TouchID no problem up until I updated to iOS 7.1 today. After deleting my prints I'm able to make it halfway through re-adding a new print before the sensor quits. Tried it several times with the same end result; no more TouchID for the time being. :(