Fairphone 4 reboots

what do you think what occours?

Hard to say, what I see on my screen could be irrelevant to what goes on under the hood. It will need to happen more often to find a common factor. Once instance I unlocked my phone, got a Teams DM and then rebooted. The other instance I was watching a YouTube video.

At least the SIM is still unlocked and the phone is decrypted (I guess). So this soft reboot doesn’t numb your phone when it happens in your pocket, if I’m correct.

Edit: uptime is still 48 hours, so the phone doesn’t fully reboot leaving apps unlocked and the SIM as well. That at least limits the impact.

You are using a SD card, or? How is it formatted? As there are still overall issues seen with SD cards in the FP4 and SD cards can cause trouble irrespective of the device, I would keep that in mind…

I use one, as external storage. However, these issues didn’t happen before with the same SD card. It could still be related, but there are more (mostly cheap) phones with sudden reboots that don’t have SD cards. For example my OnePlus One had similar issues. Let’s hope it won’t happen again, and if it does I hope it’s easy to fix :slight_smile:

It hasn’t happened again, so that’s a good sign :slight_smile:

Hope it stays that way for you !

For me it is definitively related to the 5G setting. By the way, no SD card for me. Also been travelling the last 2 weeks, incl to other 5G areas, but no reboot at all…Just this strange basestation back home… :slight_smile: Will be there next week again…


just a me too, and for me it’s definitely related to 5G. i’ve removed my sd card, just to be sure, but if i do a network test (rtr netztest here in austria) and if i’m on 5G the phone locks up and reboots a few seconds later. i’ve disabled 5G for now and the network test succeeds.

the reboots do not happen all the time, sometimes the network test is successful even on 5G.

i also had these reboots when watching youtube or browsing with firefox, connected to 5G. so IMHO it’s not app related.

i’ve only discovered that 5G might be the issue yesterday, so will keep you posted how stable the phone is when only using 4G.

ah, and i also did a hardware test as recommended in the FAQ, the test app reports no errors.



a quick update: phone is running stable with 5G switched off. 2 weeks of LTE usage without any reboots. as soon as i enable 5g i’m back to reboots if downloading via 5G.

@fairphone: is this a known issue?


I think proper debugging (with e.g. logcat) is required before we point at 5G. There is a lot going on we don’t see. I had a sudden soft reboot today as well. It has been almost a month since. So 2 weeks of a stable run could be unrelated to 5G, I have 5G enabled BTW.

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To make Fairphone aware please #contactsupport

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@tosmi After switching from a 4G to a 5G contract at A1 i suddenly have the same issue. Out of the blue sudden reboots, where i can do nothing, because as soon as it has restarted it locks up again with getting not responsive and rebooting.

But i have no clue what is causing this, despite of working for A1 (just in an IT department).

hi, to be honest, my problems seem to fixed with the upgrade to android 12. i’m currently running fp4.sp25.b.058.20230318. logged in to a1 via 5g. no reboots so far…

Still affected me yesterday on build FP4.SP29.B.069.20230510

so leaving it on 4g for now

I have noticed that my FP4 spontaneously reboots from time to time. The first time I have noticed it, I thought I might have a bootloop issue - it was continuously rebooting all the time. Then I have realized that the building had a weak 5G signal inside - I have switched off the mobile internet, and the phone stopped rebooting. Switching it back on sent the phone into a reboot again.

This was a couple of months ago. Since then, I have experienced such behaviour multiply in various locations - all of them had a weak, barely existent - yet existent - signal; typically 5G - but I may be mistaken on this.

The issue does not really bother me: I switch off the mobile internet until I pass the area of poor connection, and everything works well. Although, sometimes it can be an annoyance - e.g., when going on the bus, doing something on the phone, spontaneously searching for something on the internet without paying attention to the connection quality, and getting the phone reboot.

Finally, I cannot claim this has not happened until a few months ago. It may have. From time to time, I get messages to unlock with PIN instead of a fingerprint, for the sake of security. They always come after a reboot (intended or otherwise), and sometimes without a reboot I know of. I remember taking the phone out of pocket previously and being asked to enter PIN, even before I have noticed the unintentional reboots. Therefore, some of these may have been the consequences of unintended reboots that I have not noticed.

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My carrier doesn’t support 5G at all, but I’ve noticed random shutdowns before. Never when I’m at my apartment, always when I’m close to the center of the city where I assume 5G is more popular.


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Yes it has been noted, see above.

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I also had the reboot problems on my fp4:

  • At the exact same locations the phone suddenly reboots
  • When connected to Android Auto, and navigation with waze, suddenly the phone reboots, and causes Android auto in the car to crash also

I disabled 5G 2 weeks ago, and no more reboots. I really think this problem is 5G related.
So, we have a work around for this problem. Hope FP will fix this in the future

Unfortunately the problem is not simply about 5G: I’m using 5G ever since I’ve bought my FP4 (7 months ago), in various places around the country, with good reception, bad reception, reception jumping from 5G to 4G and back again, and I never had any spontaneous reboot (okay, maybe one, but not more) (I do have other issues though, so it’s not like I have the perfect FP4…).

What I’m saying is that there must be something specific about some specific base stations’ configuration, as the OP already noticed in his initial post. It would take a Telecom RF specialist to debug this.

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I agree. It’s not like 5G generally causes those problems. But there seem to be combinations that lead to crashes somehow. It is unlikely to be completely in the hands of Fairphone to solve this and will probably need a lot of incremental debugging on multiple ends. So while it might get better and it could be worth to try again every now and then, the problem might not go away completely for a long time.


Or it might, as suddenly and inexplicably as it arrived, because something was changed on either side and the problematic configuration doesn’t happen anymore… :grin:

Do you feel lucky?..