I am currently in the United States: when I slotted the physical microSIM card I have here (carrier: Tello, a T-mobile MVNO) into my FairPhone it works for a while (~10 minutes), then the phone reports that there is no SIM card inserted. If I turn the phone off and on again, it still reports that there is no SIM, but if I take the battery out, physically remove the SIM and then slot it back in, when I turn the phone on it gives me another ~10 minutes of normal functioning, before cycling back to not recognizing the SIM. The same phone and same SIM card worked fine when I was last here, 9 months ago.
It would seem not to be a problem with the SIM card itself, since it works fine with a different phone I own. It also doesnât seem to be a problem with the individual SIM slot, because the same behavior occurs whether I put the SIM in one or the other slot, and, more importantly, does NOT occur when I put in my Italian SIM card (carrier: CoopVoce, a TIM MVNO), which still connects over here through roaming. Anyone seen similar behavior? Suggestions??
I will add, also, that in the past, whenever I used Telloâs online IMEI checker to see if my Sony would be approved, it was rejected⌠even though T-mobile itself and other T-mobile MVNOs approve it, as it has fully operational VoLTE with T-mobileâs network, and all the required LTE bands.
Thatâs whatâs stumping me! I was wondering if it was a software update or something-- The IMEI tool on Tello says my phone is good to go with a physical SIM, which is what I have. The bands 4 & 5 for 4G overlap between T-Mobile and the FP3 (but even if they didnât, wouldnât the phone say that there was no signal, as opposed to no SIM in the phone??).
Not entirely sure what âIMS registrationâ is (sorry! Iâm not technical!): when I dial *#*#4636#*#* I get a Testing menu with three options: Phone information, Usage statistics, and Wi-Fi information. When I choose the first, it gives me info for Phone 0 and Phone 1 (presumably the two SIM slots?), but it lists nothing beyond the IMEIs, and under IMSI it says: Unknown.
Thanks for the thoughts, though: it looks like my next step is talking to the Tello peopleâŚ
Perhaps bring this up with the carrier. This is the IMS registration unique identifier. On my FP3 for instance the long number starts with my MCC, MNC.
The way that APN are set up changed in AOSP ~early 2026 so conceivably your SIM / phone relationship needed to update.
I am going down an APN rabbit hole, and will contact Tello shortly. With respect to your tips in the linked post, and in particular:
I am having trouble because when the FP3 indicates there is no SIM in the device there doesnât seem to be a place to modify the APNs, that is to say, the options in Settings > Network & internet are greyed outâŚ
Maybe Iâm not looking in the right place??
First of all, do you see an error in existing APN compared with published?
If yes and you want to correct it you would hope to use the top right + button on the APN screen. (This is generally recommended over Edit an âexistingâ).
Hopefully your APN will Save ⌠and the save will be (semi) permanent. You have to subsequently select your ânewâ APN. Hopefully you will be online with Wi-Fi and the setting will fully reset on reboot.
The need to remove SIM might happen if your ânewâ APN was not adopted (perhaps APN reverted to âoldâ). I guess the Remove SIM idea is an advance on the above ⌠aiming to adjust the values such that the âwrongâ one is overwritten if say the âwrongâ one existed on the SIM card.
Well, thatâs just the thing, @aibd : since the FP3 says âNo SIM card - No serviceâ, there seems to be no option in the Settings app for me to even view what the current APNs are. Even though I am on wi-fi, the Calls & SMS and SIMs options under Settings > Network & internet are greyed out, and it was under one of those (if memory serves) that one got access to the APN controls. So, if this is the problem itâs a sort of snake biting its own tail (no SIM service because problem w/ APNs, but no access to APNs because no SIM detectedâŚ).
I tried this, removing my SIM card, as you say, no APN found.
In one / some of the AOSP âConnectivityâ pages I did see a reference that might suggest (reading between the lines) that particularly MVNO may find themselves having to reissue SIM cards for 2026. This has cropped as a solution two times, I think, on the forum.
Yes, I did use the search function, same result.
I actually also used one of the small windows of activity of the SIM after I manually re-slot it to reset the APNs to default and chose the carrierâs (Tello) ones from the menu, and yet the same behavior followed, that is, eventually the FP3 reported âNo SIM - No serviceâ.
This is sounding increasingly likely, and I will try it next, when I get through to Tello support.
Just to wrap this up, I contacted Tello support, and they did a network reset for my account, which seems to work (3 days in now, so far so goodâŚ). So, looks like it was a service provider-side problem all along.
Thanks to @aibd and @Taurus for your help!
Search: APN