The Magnetic Field Sensor on my HTC One M8 has stopped working. I believe it was when the firmware was last updated. The effect is that my compass app and Google Sky Map no longer work. If it is a firmware problem, then other users will have the same problem - otherwise it's a problem with my phone.

So that's my question - do other users have the same problem? If so, then I plan to get on to HTC to find out when they are going to fix it.

Googling the problem shows that an identical problem has happened before when the firmware was updated, but I couldn't find a reference to the latest update.

Looking at the list of sensors using the CPU-Z app shows the value of the Magnetic Field Sensor to be fixed at 0.0µT.

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

My M8 is on the latest Lollipop firmware (4.16.401.10) and the magnetic sensor works fine.

Hi thanks for the reply. Lollipop is the Android version (5) not the HTC firmware which is the number you have quoted. Going by the numbers it's an earlier version than mine so doesn't really answer the question, except it is more likely the update has broken it.

4.16.401.10 is the latest firmware version - it came along with the Lollipop upgrade.

Go into hboot (power off, hold vol-down, power on) and you should see that listed after "OS" (eg "OS-4.16.401.10)

(See here for the firmware versions released for the European M8's).

Presumably you're looking at settings/about/software number. That's the software build. I use a custom ROM so have a completely different string there.

OK, I did that and have OS-4.19.161.2, which is the same number that I quoted earlier

The date, two lines below that is Jan 16 2015,19:01:10.27740

Over to you...

4.16.401.10 is unlocked version

4.19.161.2 is Vodafone

Beat me to it! I've never had a branded smartphone and hadn't realised that they use different firmware numbering sequences to the OEM. Sorry ...

I suppose you'll have to wait for someone with a Vodafone-branded model to say whether they have a problem. However I'd expect the firmware to be pretty similar; particularly when it comes to sensor drivers.

What results do you get when testing the sensor using HTC Diagnostic Test?

Dial *#*#3424#*#*

Hall-sensor is magnetic field

I'm assuming you meant ##3424## (not sure where those extra quotes came from). Anyway, when I dialled ##3424##, first of all it said 'USSD CODE RUNNING' then I got a message dialog saying 'Connection problem or invalid MMI code'.

Looks like my easiest option is to ask in my local Vodafone store.

The number you dial is *#*#3424#*#*

star,hash,star,hash,3,4,2,4,hash,star,hash,star

Just checked mine, on vodafone. And it's working fine for me

Oh thanks - the asterisk in this font is so tiny that I didn't recognise it at such (it looked like a single quote at first sight).

When I select the Hall Sensor test, it says to place the "magnetic fixture" in the blue square. I presume that's a small bar magnet, which I don't have, unfortunately. Actually, I can't see how that tests how the phone is oriented relative to the Earth's magnetic field, which is what it's all about.


Thanks very much. Do you have exactly the same versions as listed at the end of my OP? (Settings / About / Software information)

Lightbulb moment: fridge magnet!! I did the Hall Effect test and it worked OK so that is not the problem.

Once I hear back from cwmparc that he has exactly the same versions of the software, I guess it's the factory reset route.

Yes, exactly the same

Thanks. Guess it's factory reset time