Develop Bugs

[Q] Network Issue with rooted T-Mobile Galaxy S3

So I've had this phone for over two week now, and I rooted it and flashed it with FrostyJB v5. Everything was running well (excluding the battery life, which was better in v4 but that's a different topic). I was at my school connected to their wifi earlier tonight and when I left school, I can't make any phone calls (i have a circle with a slash through it where my signal bar would normally be). I think it has something to do with my APN or network or something? I'm honestly new to this. I would appreciate it if some one could help me solve this problem. The phone is a T-Mobile phone, which I bought from a T-Mobile dealership. The SIM was working properly until tonight. I tried removing the SIM and rebooting, putting the SIM back in, rebooting. etc.
TLDR: My 4G doesn't work, I'm not connected to any APN, my phone is rooted and flashed with FrostyJB v5 but I bought it from a T-mobile dealership with a T-mobile sim card. Help. Please.
I can provide addtional information if needed

Is your imei still there? Check it in settings/about phone. And are you sure airplane mode is not checked? Were you doing anything developement wise when it went out?
sent via galaxy s3 in boss mode @ 2.1ghz

tgamble160 said:
Is your imei still there? Check it in settings/about phone. And are you sure airplane mode is not checked? Were you doing anything developement wise when it went out?
sent via galaxy s3 in boss mode @ 2.1ghz
Click to expand...
Click to collapse
my imei is still there. it is not in airplane mode. I can't connect to my 4G or my T-Mobile network. I was not doing any development when it suddenly turned off. I was walking out of my school around 11:00pm CST (if it helps, I get no reception at my school's building). I turned my wifi off and turned my 4G on via drop down menu and it wouldnt connect. I tried rebooting my phone several times, using HOT BOOT and REBOOT.

Can an mod/admin close this thread out? I solved the issue. You need to turn off wifi calling for it to work. dur. sorry

LTE driving me insane, lose it after switching to airplane mode.

Hello, I am on a rooted stock Jelly Bean Telus ROM with default recovery (I flashed the rooted stock image through ODIN). Every now and then I will lose LTE even though I am in an LTE area. I try to do the trick of turning on airplane mode and turning it off to get the connection to reset. This actually doesn't do anything. HOWEVER, if I restart the phone, I get LTE back with 20 seconds. Once it restarts it can stay on LTE for a long time. Even when I get a call it'll go to 4G and then switch to LTE once I finish.
But here's the kicker. If after I restart it, get LTE, THEN switch to airplane mode and switch back, it will never, ever connect to LTE again. I have to restart the phone to get it back. I've just done a hard reset and the same problem occurs. This sounds completely ridiculous and I've tried everything. Has anyone heard of anything as absurd as this?

Aftcomet said:
Hello, I am on a rooted stock Jelly Bean Telus ROM with default recovery (I flashed the rooted stock image through ODIN). Every now and then I will lose LTE even though I am in an LTE area. I try to do the trick of turning on airplane mode and turning it off to get the connection to reset. This actually doesn't do anything. HOWEVER, if I restart the phone, I get LTE back with 20 seconds. Once it restarts it can stay on LTE for a long time. Even when I get a call it'll go to 4G and then switch to LTE once I finish.
But here's the kicker. If after I restart it, get LTE, THEN switch to airplane mode and switch back, it will never, ever connect to LTE again. I have to restart the phone to get it back. I've just done a hard reset and the same problem occurs. This sounds completely ridiculous and I've tried everything. Has anyone heard of anything as absurd as this?
Click to expand...
Click to collapse
Had the exact same problem with a Telus rom, I dont suppose you're on ATT by any chance?. Mine wouldn't connect to the mobile data network when coming off a wifi connection and would just hang in limbo until i switch mobile data on and off. Dumped it and went to a ATT based rom, problem solved. One thing I noticed is that the APN options with the telus rom are different than ATT roms, the apn type in particular

Ask in Q&A or the sticky thread for LTE
Thanks

G4 H815 doesn't stick to LTE - apn okay, lp&mm stock kdz already flashed

Hello!
I have a big problem with my G4 (H815 version, Germany) beginning with the switch from CM13 to the (stock based) Genisys 3.2 ROM. I've tried to fix it for three days now but without success. It doesn't stick to LTE anymore like it should do and did before. After a reboot it does sometimes connect to LTE but after switching back from wifi or airplane mode it's showing the "no signal" icon. Then it takes some seconds until it reconnects to the mobile network but now just to 2G or 3G. From this point it's not willing to reconnect to LTE, even not through the manual RAT-selection. "Force LTE" using the hidden menu then results in no network connection. However, after restoring my EFS-partition-backup with TWRP (from a time when it was working perfectly) it's connecting to LTE directly after boot but only once and only until you toggle wifi or go offline - like described before. After the next reboot it will mostly connect to 3G and then maybe switch to LTE sometimes or not.
Of course I have checked, deleted and restored my APN multiple times, I have also recovered to a stock V20b and V10d .kdz using LG UP in refurbish mode. Unfortunately even on the fresh and untouched V10d install it shows the same strange behaviour. Restoring the CM13 backup (including EFS partition), which has worked perfectly before, shows the same network bug now.
My sim-card is still working perfectly in my other phones. It still connects and reconnects almost instantly to LTE in my old S4 in places where the G4 did the same but struggles now.
I have even tried the cdmatool which is used to unlock additional LTE bands. I didn't change anything but it does show all usual LTE-bands which are needed for my provider.
Does anyone have an idea what I could try next? I'm living in an area with much better LTE than 3G connection and paying for a quite expensive LTE contract so a working LTE is very important for me. If I don't get that to work again I would need to replace my just over one month old G4 :crying:
Many thanks in advance for your answers
f-rouz

Meanwhile I have also tried another simcard. Still no LTE

i have the exact same problem, well, almost. no unlocked bootloader, but when i first got the phone i root injected the system.img and flashed away, thought everything was fine. now it just doesn't reconnect to 4G. well, at home at least. on my S4 i get 4 out of 5 bars on 4G, with the G4 i get 2 or 3 bars out of 5 on 4G, so the signal isn't great but good enough. i live in hastings (a town) and went to brighton today (a city) where the signal is max 4G, and the device does pick it up. but as soon as i go through a 3G area to home, it doesn't reconnect. have tried flashing original system.img back, upgrading to MM 6.0 after factory reset (via LG bridge), then downgraded again to V10c via LGUP - factory reset before the downgrade, no joy, still the same.
when you say you have forced LTE in hidden menu, did you try this - enter 277634#*# in dialer and go to field test > modem settings > lte band selection and select the band for your operator, which can be found on 'wiki europe lte bands'. there were two bands for my provider (three UK) and band 3 was what i wanted. i can now switch to 4G but it's a pain having to this every time i come home ( i use my phone for home internet via tethering).
worst part is, having refrained from unlocking the bootloader to save the warranty, i phoned LG today to send it back as faulty and explained i could switch it to lte band 3 via the hidden menu and they told me my warranty was now invalid as had OPENED the hidden menu (they told me this after taking my imei). so if anyone reads this and phones LG for a repair, don't tell them you have accessed the hidden menu if you have done what i did.
think i'm just gonna sell the phone, make a palpable loss and buy another one, as i love the phone

Wow, I haven't thought that from LG. I feel like I've searched the whole internet already and nobody has a solution to this problem. I'm about to send my G4 back to Amazon (or sell it otherwise), hope the best and get myself a Oneplus Two because the G4 seems to be too *****y from the development standpoint. I've never had a situation like this with my previous Samsung phones since 2009. I will miss this camera though. And the NFC and the wireless and fast charging capability... the G4 is a nice phone nevertheless...
Edit: And yes, I have tried the "277634#*#" hidden menu, although it isn't accessible through this code on MM any more (you need a terminal command to start this).

Have you tried limiting it to 4G/2G in hidden menu? Mine also have a similar problem in Lollipop in that it is very aggressive in dropping to 3G. That worked for me. Phone doesn't drop to 2G much provided you have decent LTE coverage.
Now I'm on Marshmallow and not rooted, thus cannot do the same. Though it seems to be sticking to LTE a bit better than before.

I have tried that but it doesn't work. As I don't get any network connection wenn forcing LTE only, forcing LTE/2g results in 2g only.

My G4 still doesn't want to connect to LTE so I have ordered a S6 now... As I still have no idea what was causing this I just can't risk that happening again. It has been a short journey for my first LG and me and I really liked my G4 actually... Bye G4 community

you just needed to flash the stock modem, most likely

Unfortunately, it isn't that easy. That was of course the first thing I did (and not just one time)...

Force LTE only

Good morning all.
My S9 is completely stock (Android 10) and I don't want to install any custom ROM.
Is there a way to force LTE only (Three network/UK)?
I have tried #*#*4636*#*# but this doesn't work. I have used a couple of apps that have given me access to the settings and changed it to LTE only and this is confirmed in the mobile settings page but the phone keeps reverting back to 4g (not 4g+).
I definitely have 4g+ here because it does connect if I reboot my phone and the download speed is double my normal rate but I cannot get it to stick.
Is there a specific APN I could use?
May I ask you for advice?
Thank you.

SSThing said:
Good morning all.
My S9 is completely stock (Android 10) and I don't want to install any custom ROM.
Is there a way to force LTE only (Three network/UK)?
I have tried #*#*4636*#*# but this doesn't work. I have used a couple of apps that have given me access to the settings and changed it to LTE only and this is confirmed in the mobile settings page but the phone keeps reverting back to 4g (not 4g+).
I definitely have 4g+ here because it does connect if I reboot my phone and the download speed is double my normal rate but I cannot get it to stick.
Is there a specific APN I could use?
May I ask you for advice?
Thank you.
Click to expand...
Click to collapse
You can try with Force LTE Only app on Play Store since Scamsung is kinda blocked the Radio edit part on ONEUI. But be aware that on some firm, Scamsung devices will not be able to make phone call or receive text msg when on force LTE only mode!

That's one of the apps I have used but the phone just reverts back to 4g (even though Network Mode now shows LTE only).

Looks like I have been misunderstanding my network terminologies.
What I am trying to do is force my phone to stay on the 4g+ signal, because I get much better downloads. It is definitely available here because I connect to it for a few minutes if I reboot my phone. My phone is completely static with good, no fluctuations, signal.
Can this be done?

Question Unable to retain/regain signal without reboot/airplane mode toggle

I'm at my wit's end with this. I got this phone last year and it worked perfect until the stock Android 13 update. Then it wouldn't hold a signal to save its own life. I finally have wifi here so it's not as much of an issue, but when I leave my house I have to toggle airplane mode to get it to work again, or it's stuck on "emergency calling only" forever. I did recently put Lineage on it, thinking maybe that would help. The last couple updates it's a little better, it will sometimes get signal back on its own. However more often than not I have to toggle airplane mode or reboot to get service back. This happens all the time, a dozen or more times a day depending on how often I lose service. I did try to search the forums for an answer, but I kept getting errors back with the exception of one result with the same issue that said "tmobile only" under the fix.
I have:
Reset network settings
Reset APN
Manually selected a carrier and switched it back
Cleared cache through Android Settings
disabled/enabled mobile data
Toggled Mobile data always active
Any help would be greatly appreciated. Seriously considering going back to my LG G8 ThinQ and selling this thing, but I love the cameras on it. Side note: When I put the SIM in my old phone none of these problems exist.
Model: LE2125
Carrier: Verizon
Lineage ver.: 20230613

Caboose27 said:
I'm at my wit's end with this. I got this phone last year and it worked perfect until the stock Android 13 update. Then it wouldn't hold a signal to save its own life. I finally have wifi here so it's not as much of an issue, but when I leave my house I have to toggle airplane mode to get it to work again, or it's stuck on "emergency calling only" forever. I did recently put Lineage on it, thinking maybe that would help. The last couple updates it's a little better, it will sometimes get signal back on its own. However more often than not I have to toggle airplane mode or reboot to get service back. This happens all the time, a dozen or more times a day depending on how often I lose service. I did try to search the forums for an answer, but I kept getting errors back with the exception of one result with the same issue that said "tmobile only" under the fix.
I have:
Reset network settings
Reset APN
Manually selected a carrier and switched it back
Cleared cache through Android Settings
disabled/enabled mobile data
Toggled Mobile data always active
Any help would be greatly appreciated. Seriously considering going back to my LG G8 ThinQ and selling this thing, but I love the cameras on it. Side note: When I put the SIM in my old phone none of these problems exist.
Model: LE2125
Carrier: Verizon
Lineage ver.: 20230613
Click to expand...
Click to collapse
Maybe contact Verizon support. They should be able to fix it or at least tell you what the problem is.

TheGhost1951 said:
Maybe contact Verizon support. They should be able to fix it or at least tell you what the problem is.
Click to expand...
Click to collapse
I tried that. I couldn't get anyone that was a technician on the phone and eventually after three days of not getting an answer they closed the ticket.

Caboose27 said:
I tried that. I couldn't get anyone that was a technician on the phone and eventually after three days of not getting an answer they closed the ticket.
Click to expand...
Click to collapse
WOW, glad I am with TMO. Their support is the best I have ever worked with. To me they set the standard.

You said you reset the APN, but did you check to see if the APN is the same as on your other phone that doesn't have any issues with mobile service? Maybe check to see if they are the same, and if not put the APN in that works

Amazoniac said:
You said you reset the APN, but did you check to see if the APN is the same as on your other phone that doesn't have any issues with mobile service? Maybe check to see if they are the same, and if not put the APN in that works
Click to expand...
Click to collapse
That's a good idea, I'll do that tomorrow. Thaanks!

Assuming you're unlocked and rooted since running Lineage, so add this module in Magisk, and maybe also enable mobile data always active in developer settings for now as well.
[TMO] OOS/COS DATA FIX
TO CLARIFY THIS IS A ROOT ONLY FIX After gaining root install given module. Data is now retained. Even after reboot(s). No empty slot or waiting. Issue is TMO variant is showing multi sim. So props were added to make it like a conversion to...
forum.xda-developers.com

Caboose27 said:
I'm at my wit's end with this. I got this phone last year and it worked perfect until the stock Android 13 update. Then it wouldn't hold a signal to save its own life. I finally have wifi here so it's not as much of an issue, but when I leave my house I have to toggle airplane mode to get it to work again, or it's stuck on "emergency calling only" forever. I did recently put Lineage on it, thinking maybe that would help. The last couple updates it's a little better, it will sometimes get signal back on its own. However more often than not I have to toggle airplane mode or reboot to get service back. This happens all the time, a dozen or more times a day depending on how often I lose service. I did try to search the forums for an answer, but I kept getting errors back with the exception of one result with the same issue that said "tmobile only" under the fix.
I have:
Reset network settings
Reset APN
Manually selected a carrier and switched it back
Cleared cache through Android Settings
disabled/enabled mobile data
Toggled Mobile data always active
Any help would be greatly appreciated. Seriously considering going back to my LG G8 ThinQ and selling this thing, but I love the cameras on it. Side note: When I put the SIM in my old phone none of these problems exist.
Model: LE2125
Carrier: Verizon
Lineage ver.: 20230613
Click to expand...
Click to collapse
Exact same issue, unlocked LE2125, TMobile simcard. Didn't have issue on custom ROM, but this is happening on OOS13. Tried everything NSA SA 5g dev settings nothing worked. Living with trying to remember to toggle airplane mode periodically.
Try App "connection stabilizer booster" actually helps w root
Connection Stabilizer Booster - Apps on Google Play
Fix cell and wifi connectivity issues. Improve your mobile internet experience.
play.google.com

Life got in the way and I haven't had a chance to try this yet. Probably this coming weekend.