Modem Hardware bad? Not ready for 5g??
Just wanted to share this experience with everyone here at Pine64. I think this might be very important. Recently I had some problems with my PinePhone on March 1st. The date is important because on this day I could no longer make any phone calls or even make phone calls. I thought it was a software issue, but long story short it appears to be a hardware issue, the modem to be exact.. My rationale for this is because ATT (the carrier I use) shut down all 3g by the end of February, thus for me the problem started exactly on March 1st. Also, I discussed the issue with the ATT reps and their IT department. The IT checked everyone...all was perfectly fine on their end. The reps provided me a new sim card and I got the same results, could not make/receive phone calls (no internet either). The IMEI checks out ok in their database, but upon further inspection they notice that the VoLTE was set to "false". Meaning I would not be able to make/receive phone calls (or internet). Yet strangely enough I can receive text messages. They tried putting in two new sim cards, same result. They put my sim card into the latest iPhone and suddenly the iPhone could NOT make phone calls either. It was using the IMEI from my PinePhone. Then they changed my sim card in the iPhone to match the IMEI from the iPhone and suddenly it could make phone calls. The sim card with the iPhone IMEI number was then placed into my PinePhone and then suddenly my PinePhone could make phone calls! idk, PinePhone users may start having a lot of problems as the other carriers start phasing out 3g and replacing it with new 4g/5g tech. In my opinion I think Pine64 needs to update their hardware for better compatibility. Eventually 3g will be gone and there may be a lot of PinePhone users with no cell service. Could become a huge problem. But perhaps other carriers who already dropped 3g, will fair better with PinePhone...can't confirm that.
The Pinephone modem supports 4G/Volte. There are a lot of people using it just fine.
From your description the problem is not the modem, but AT&T's management systems. If the modem was the problem then using the SIM from the iPhone wouldn't have allowed it to make calls.
It’s your carrier, not Pine.
I’m in Europe & been on 4G just fine with Mobian for the last few months.
Satisfied PinePhone, Pinebook Pro & PineTab2 owner; Thank you Pine64Team for your work!  Smile
"It has begun." = AT&T has already shut down its 2G GSM network and most recently said it will shut down 3G GSM/UMTS in February 2022.

OP is stating what I feared for this year:

most modems were reporting 4G service but in reality certain features (voice, SMS, etc.) were falling back to 2G/3G for carrier-modem compatibility.

Every saying "LTE just works" should be forcing their modem to 4G only. No falling back anymore.

Let's see what else breaks.
PPv1.2a running PMOS ... almost a daily driver!
Back in 2020 there was a time I suspected a modem problem with my Brave Heart modem.

But it turned out to just be the early software.

I currently own 5 of the original Pine phones, and one Pine phone Pro Explorer edition,
ALL of them have a working modem.

While I have been testing different operating systems --- I have wondered about the different hardware/firmware
updates that come with these different O.S.'s....

For example, is a firmware update for Mobian compatible when I test drive Arch or Manjaro ?

(When you swap operating systems, like swapping sd cards, it does not automatically swap your firmware.)
   Donate to $upport
your favorite OS Team
It's not as simple as saying "LTE Just Works" - it won't for everyone, for a variety of reasons. One of these is the modem firmware's limited selection of profiles as discussed in this issue for the open version of the modem firmware:

That isn't the problem in the case above though - with the SIM from the iPhone the modem in the PinePhone works with VoLTE, and with the SIM from the PinePhone the iPhone can't do VoLTE. The other part of the problem is that, whether by misconfiguration or by policy, some carriers block VoLTE from some phones that are capable of using it. Some are openly operating explicit allow or block lists of phone models. It appears AT&T aren't doing this, but are inappropriately associating VoLTE capability with the SIM not the phone, with no clear explanation of how it gets set or how it can be corrected.
Posting here from y PP running AT&T, I can confirm it's something to do with IMEI. Mine is registered for a Pixel 4a, which makes it work fine with the PP.

Earlier in the year, when AT&T was pulling the cord on 3G, I had my IMEI for a Xiaomi Pocophone, and it did NOT work in the PP. I think the key to using AT&T is unfortunately registering with a different IMEI first, then plugging into the PP
AT&T has begun whitelisting phones which I suspect was the problem with OP. The pinephone is not an "approved" device for them so they block the sim. The iphone sim worked because it thought it was in an iphone.

Tmobile does not whitelist, so as long as a phone has volte it should work.

Possibly Related Threads…
Thread Author Replies Views Last Post
  power circuit can't charge battery and can't supply enough power for modem or wifi vortex 2 193 02-17-2024, 04:15 PM
Last Post: vortex
Bug PinePhone modem keeps "disappearing" Kevin Kofler 14 4,881 03-22-2023, 05:28 PM
Last Post: Kevin Kofler
  Microphone on Hardware Model 1.2 is Unusably Noisy In Some Circomstances ASmartSuitedSimpleton 4 3,440 03-03-2023, 01:33 AM
Last Post: emmausa
  modem not working michelinux 0 839 02-16-2023, 04:56 AM
Last Post: michelinux
  modem not detected al_x 3 3,983 02-15-2023, 11:17 AM
Last Post: fxc
  Supported Carrier and Modem Bands NachoMomma 2 1,280 02-05-2023, 11:27 AM
Last Post: wibble
  Is the hardware still being developed and refined? orbital 10 4,573 09-01-2022, 08:05 PM
Last Post: orbital
  How to check hardware revision? jojuma 1 1,433 07-16-2022, 12:28 AM
Last Post: bokomaru
  firmware udate Quectel EG25-G modem alwi 7 4,956 07-06-2022, 01:43 PM
Last Post: user641
  Need command to tell what modem firmware I am on. purpletiger 4 2,567 07-06-2022, 12:35 PM
Last Post: Zebulon Walton

Forum Jump:

Users browsing this thread: 1 Guest(s)