Develop Bugs

HELP! Major network problem :(

Hi all,
I got my Desire from the British carrier "Three" last April when it came out. It was stocked with Android 2.1 but the phone was unbranded and not locked so making life much easier.
I rooted the phone weeks later and flashed a number of various roms and radios (usually newest ones recommended by rom developers) and just played around with them. No problems ever occured and everything went smooth.
However a while ago (about 4 weeks I would say) strange thing happened: when the carrier 3 does not gave 3G coverage it usually switches to other network's 2G roaming service. It is also possible to switch to 2G permanently by forcing it via phone settings. It stopped working in Central London for me while still worked elsewhere (very strange) so I had to rely only on 3G service. I thought it was a network issue at first but now I'm not sure.
Later (or at least so I noticed) the connectivity started fooling around: even when standstill (i.e. NOT in a train, bus etc.) and staying at home the network connectivity just disappears all of a sudden. Sometimes it comes back by itself and sometimes I just do it manually via netowking settings. This is much more common when on the move (i.e. on the train etc. even though it never used to happen before). Moreover, sometimes while manually searching for network it says "your sim would not allow to connect to this network" even though I try to connect to the correct one. Instead I switch "WCDMA only" and "WCDMA/GSM auto" options and connection comes back by itself. Then it disappears again after a while. Even more strangely, connection does not disappear if I am talking on the phone with someone but in other situations (such as browsing internet) it just disappears and I see no bars in network reception indicator and cannot connect to internet or make phone calls.
I know 3 has a reputation (deserved or not) of having "bad" network but I don't think this has anything to do with that. My Desire used to work fine before and never had such problems (except in specific spots which have bad coverage). Moreover, I have another old phone and it works fine without any problems with networking while the Desire messes around. I am sure it has either to do with firmware or, worse, hardware.
I have tried a number of roms, radios and settings and it's the same thing all over.
If nothing works is there a way I can still bring it to warranty service after flashing "unrooted" stock rom if there is one available? I'm so frustrated because I have no idea why this is happening.

Its because three have switched off 2g roaming I have the same problem. Search Google
Sent from my HTC Desire using XDA App

No Mobile Data

Hi, its my first post on the Z1C forum.
I just got one yesterday to replace my Nexus 5 and am accounting a few things I need help with since I am new to the xperia line of phones.
So my phone looks like this (for data) however I can't browse anything. I have mobile data enabled, national roaming and preferred network being 4G but nothing is working. With my Nexus 5 my data just worked so I am unsure why this is happening here. I can send texts and make calls just fine. Phone is on lolipop 5.0.2
The wifi signal in my room is terrible and its constantly dropping and when that happens I can't do anything with it.
I am on tesco mobile with a 2GB 4G plan.
http://imgur.com/GBhJJEW
--------
Edit: So I looked around I went into mobile network and scanned, found tesco and registered. So I have 3G data now, but 4G isn't registering. Maybe I need to phone up Tesco and ask them.

Or maybe it's just not a 4G mast where you're connecting?

Is problem "no mobile data at all" or "no LTE connection" ?
Can you transfer data on 3G?
If so - check twice if your SIM card is LTE compatible.

I had to adjust the APN on my phone when I first got it as the one it autodetected wasnt correct. Try that out.

Hi so i just got a z1c and this happened to me. I could send and get text/calls even get notifications and updates. I called sony and t-mobile, nether could help me. Then i found a option under "more" in settings to update "Internet settings" find your server and hit ok. Try it out, i hope this helps.

In my case I needed to contact my carrier to enable 4G. Tried it?
Not sent by me.

settings.>>other>>>internet settings>>>download internet and mms settings...
this should do the trick...

Inconsistent Connection
I got my Z1C a few days ago and updated it to Lollipop yesterday. Ever since the update, the phone has been dropping data connection. I don't know what's the initial cause yet but as it stands, in order to get it working again I have to take out the SIM and reinsert it multiple times. I'm watching it carefully tho because it seems to happen whenever I start Candy Crush. Is there anybody else having this experience?

LG G3 D855 Odd behaviour when roaming

I have a G3 D855 International (or is it Taiwanese?) version - running the latest stock LG build, which identifies itself as LRX21R.A1440231662, version V20u-TWN-XX, Kernel 3.4.0, Android 5.0.
I have a Three (UK) SIM, and have recently been in California, where I observed some odd behaviour. I'd be glad if anyone is able to comment or explain any of this!
1) I never saw any 4G (LTE) connections. From other posts in this forum it does appear that this model of G3 may be incompatible with T-Mobile US and AT&T network frequencies, and if so that's understandable.
2) It seemed to have a very strong preference to connect to T-MO, but on that network it would frequently lose data connectivity, despite the phone showing a strong signal. My wife's Galaxy S3, also on Three, would stay connected all the time. If I tried manually searching for networks and selecting either T-MO or AT&T, usually that would restore connectivity. However...
3) Entering manual network selection from this state (connected to T-MO but not getting any data), the phone would display a warning along the lines of "Do you want to search for networks while there is an active data connection?" -- yet there was no data connection icon in the status bar, and no throughput. This feels like some sort of bug - the phone thought it had a data connection but really didn't?
3) Even though I would manually select the AT&T network, and get some throughput, the phone would fairly soon spontaneously reconnect to T-MO, and shortly afterwards again lose data connectivity. This became tedious and frustrating. Other phones I've had have always respected a manual network selection and stuck to the selected network, even when if another available network had a stronger signal. Not so this G3. Is this known, normal behaviour?
The only other thing that may be relevant is that for most of the time I had the phone set to connect only to WCDMA networks, because the data capability of GSM is next to useless, and since I'd not seen any LTE, and WCDMA + LTE only is not an option, WCDMA was really all I was interested in.

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)...

4G Calling/VoLTE and Wifi Calling stop working after moving between cell towers

After a phone restart, VoLTE/4G Calling and Wifi Calling work for a short period, then stops working, usually after moving around between mobile towers and/or wifi hotspots.
I find it happens whenever the device loses mobile signal, or when the device flips down to 3g and then back to 4g, 4g data service returns but both VoLTE calling and WiFi Calling remain disconnected despite being enabled in settings.
This happens on my primary SIM only. I have a second sim in my phone at the same time which works perfectly with both VoLTE and wifi calling. I upgraded from a Mi 9 phone which worked perfectly with both these SIM cards.
Looking at the device logs (With Logcat reader), I get lines like
QImsService] ImsServiceSub : [0] Permanent IWLAN reg failure (IKEv2 auth failure)
I also see
IKEV2ErrorReceiver] Canadian configure is not set, return
Other things I've tried:
Updating to the latest MIUI version (12.1.5.0)
Network settings reset
Only using the one sim
Removing the second SIM
Clearing all caches
Clearing caches and storage of things like CneApp, Carrier Services, Phone Services, Phone, anything carrier related
Resetting APNs, adding APNs with bearer set
Setting phone to prefer 4G/LTE (ie do not connect to 5G)
Removing my VPN, same problem with VPN installed or not installed.
Removing sim cards and leaving phone off for a while (an hour or so)
Getting a replacement SIM
I have not tried a factory reset yet, as I am not confident in being able to back up the phone fully and other threads with similar issues suggests that won't solve the problem.
One way I've managed to get it stable is to dial *#*#4636#*#*, go to phone and set preferred network type to "NR/LTE". The phone does not connect to 3G or below in this mode, and unfortunately this setting gets reset when the phone restarts.
At this point I think its a problem with the MIUI software version itself, or some firmware driver that comes with these versions of MIUI. I'm hoping MIUI 12.5 will fix it, but I'm wondering if anyone else has seen this issue or knows what else I can try.

Upgraded to 12.5.1.0(RJDEUXM) and the issue is still present, also tried asking my operator to completely reprovision the line with no luck.
I guess I'm stuck with this behaviour until I upgrade my phone

STEP #1) See if VOLTE works normal when switching towers with a different phone.
If it does then you can try the things below, if it doesnt maybe it might be the cellular carrier issue.
If other phones work find then please note that VoLTE mainly works on 4G LTE ... donest work on 2G or 3G and may or may not work on 5G depending on your carrier. Find out what NETWORK BAND your phone is using when VOLTE is working. You can use a app like
Network Cell Info Lite​Once you find out the band you can then use a script or use a app so it stays on that network BAND. A little more advance but it may also possibly be a DNS issue in the tables during the change of towers during the reprovisioning... you can try a script to flush the DNS and reload the tables when the network info changes or bind them statically for testing purposes.
Still doesnt work it may just be the firmware's modem issue with that phone in the way it handles re-provisioning process during cellular multiplex switching.