Magnetic field Sensor has stopped working on HTC One M8 (Vodafone)

[jeffg1]

I believe this happened with the latest HTC firmware update. The Magnetic field Sensor no longer works. This can be demonstrated by running the Google Sky Map app, or a compass app. Neither works. Another app, CPU-Z, lists all the sensors and their values. The Magnetic field Sensor shows a fixed value of 0.0µT.

Does anyone else (with the same versions as below) have this problem, or is it just my phone?

My phone: Android version 5.0.1, HTC Sense version 6.0, Software number 4.19.161.2

[hrym]

The first port of call would probably be a factory reset, which often solves update-related issues.  It's a bit of a hassle, as you have to set the phone up again, so it'll depend on how important this is to you.   If you go ahead, don't forget to back up your content and make sure your contacts and calendar are fully sync'd.  If you want to keep SMS and call logs, there are apps on Google Play that can back them up for you.

If for some reason the sensor isn't supported in Lollipop, you'll be back where you started, of course.  Maybe the thing to do is ask HTC?

[jeffg1]

I have already gone down the HTC support route and following a soft reset and starting in safe mode (Catch-22 since that disables the very apps that show me that the sensor isn't working), I have now reached the point where a factory reset is proposed. This is quite a big step, with a fair amount of preparation needed, so I would prefer to wait to hear from other HTC One M8 owners with exactly the same version numbers as me whether they have the problem.

I have posted on Digital Spy as well, and one Vodafone user has replied there saying his works OK, but I am waiting to hear back whether he is on the same versions of everything as I am.

Also on that thread, I was told how to bring up the HTC One Diagnostics (*#*#3424#*#*) to test the Hall Effect sensor, but that requires a small magnet which I don't have. Ah I just realised: fridge magnet! And the test works so that is not the problem.

[hrym]

I have, as it happens, an M8 and I also have a compass app installed.   The app includes magnetic field information and it displays that (even after the Lollipop update afaik).   It's never been quite as accurate as the same app installed on an LG G3, though.   It also seems to need recalibrating (by turning and rolling the phone) fairly frequently.   Does that help at all?   I only installed the app experimentally and haven't made very serious use of it on either device.

Re-reading your post, do I understand the last sentence correctly?   That the sensor is in fact working?   If that's the case, it could be compatibility of the app with Lollipop and that would be a matter for the developer.  Have you tried any other compass apps?   This is the one I'm using.

[jeffg1]

Just tried your app and it's exactly the same. Compass needle frozen and magnetic field value 0µT as I shown in CPU-Z.

Do you have exactly the same versions of the software/firmware that I do? It's obviously not a problem with Lollipop as that compass app works on your phone. Is it a Vodafone M8? They have their own version of the firmware.

[hrym]

Ah, good point.  No, it's SIM-free.   It's still stupidly inaccurate - and fluctuates wildly, but the magnetic field sensor is working according to the app display.   The LG phone I referred to is running KitKat (can't remember which version exactly) and is on Vodafone-branded software.

Edited to add: It's just dawned on me that one reason for the inaccuracy on the HTC could well be the magnetic closure on the case I have it in.