Develop Bugs

Intermittent data connection

My phone started turning on and off its 3g connection. Wifi works solid.
I'm on a good signal area. It's not like the 3g is on and I can't connect in anything.
The problem is that the phone turns on and off. It doesnt fix the 3g connection.
Also, Checkin service it's draining the battery a lot.
Looks like a software problem with Google Play Services and its Connection checking service.
Anybody have seen this problem?
thanks in advance.

Starting to worry right now. Did a factory reset on a flashed V10j KDZ and it didn't change.
TWRPed a 20A Lollipop rooted ZIP and it didn't change. Right now I'm trying to go back stock using LG PC Suite.
I can't understand why this can be a hardware problem because 3G actually works but it keeps constantly getting on/off in ~10 seconds intervals.
Looks like a bad system file that is messing with it.
EDIT: Also, the phone can't search for mobile networks anymore. I just tell it to do a manual search and it can't find anything.
What would this be? Modem file broke? WTH.

alfablac said:
Starting to worry right now. Did a factory reset on a flashed V10j KDZ and it didn't change.
TWRPed a 20A Lollipop rooted ZIP and it didn't change. Right now I'm trying to go back stock using LG PC Suite.
I can't understand why this can be a hardware problem because 3G actually works but it keeps constantly getting on/off in ~10 seconds intervals.
Looks like a bad system file that is messing with it.
EDIT: Also, the phone can't search for mobile networks anymore. I just tell it to do a manual search and it can't find anything.
What would this be? Modem file broke? WTH.
Click to expand...
Click to collapse
I have random disconnects/drops too, Although my 3G/LTE icon never actually goes away, just the signal.
Personally I would suspect your modem as #1 suspect.
Factory reset rarely fixes much, I would try re-flashing the phone.
If KDZ flash doesn't fix it maybe try a tot & dll flash using LG Flash Tools with modified megalock.
It definitely looks like a modem issue BUT it can be a your os. I had issues where my modem wouldn't flash from a stock flash on my S4, But manually flashing my modem would SOMETIMES work, I would have to flash the modem a few times usually before it would actually flash.

I had problems before but it was caused by network. Did you tried with different SIM card from other network?

I have the same problem and couldn´t fix yet... Didn´t try to use another SIM card to check if is a network trouble, but it´s driving me crazy to be without connection and a huge battery draining...
Any other ideas?

viniciuscordeiro said:
I have the same problem and couldn´t fix yet... Didn´t try to use another SIM card to check if is a network trouble, but it´s driving me crazy to be without connection and a huge battery draining...
Any other ideas?
Click to expand...
Click to collapse
Just try with other network SIM. I had same problem long time back with Nokia n96, Motorola defy and some other phones. Some of time it helped to set phone only to use 2g network. That was happening the most of time when i used VIP network in Serbia.
Setting only 2g signal helped sometimes but after changing SIM card, problem was solved.
This problem happen to me without reason and after some time i tried same network again, there was no problems.

Probably a different SIM will correct the problem, because after a lot of trial and error changes I realized that the current Network APN (you can reach going on Mobile Networks inside Connections and Networks [translation] in the Settings) was faulty. I deleted the APNs and made a restore. (Delete and Restore are the only options inside Network APNs).
I imagine that changing SIM cards from another carrier will reconfigure the APNs and probably fix the problem.

I´ve tried a different SIM card and didn´t found any troubles, but when I put mine, the problem come back again... So it´s a problem with my carrier. I´ve deleted the APN settings, restart, restore, restart again and didn´t solve. I´ll call them to check if they are experiencing any network issues.

[Q] disappeared LTE all firmware

What is done:
first I flash 30B bump, the problems starte. then flash 30B LGUp, flash 21a and 21c, change band in ingeneering menu, delete lteconfig, flash 30b bump with modems: 21a, 21c, 30b hybrid, change of operator, manual config APN, manual search network. All this does not help.
Any ideas?

no ideas?

Idem.
But after reboot 4G is ok, but again...every morning i lost signal 4G...only 2G/3G is ok. So..reboot & 4G is up......disappointed.

Same on my G3. I downgrade from MM to LP but problem persist.

Same here....tried rollback to kitkat stock, LP stock, CM12, Cm13, and some other roms with no luck....have just flashed stock LP for repair...

so today I tried swapping my SIM with my friend's
he is using G3 with stock 21A, and his SIM is of the same carrier as mine
after swapping, I found that my phone (and of course his phone, too) is working normally
my phone is normal even after swapping back
did some different tests like switching on and off with 3G, LTE etc., everything is normal, at least at this moment

Still working with you? So it is sim card fault? With me after searching networks everything seems to be ok, but I couldn't connect with LTE. Only sometimes successfull connection.(once a day and after reboot same...) Very strange. :/

I lost network signal randomly... i tried with 30b hybrid modem, 21a, 21c... kdz method, twrp bumped rom... and doesnt help me at all.. my network signal gets a rotating circle randomly... and in that time my phone is out of coverage... it is .... hundred times in a day... i dont know what to do, please help

same here when i use sucks 30b D855, but now everything is ok with me.
Steps that have been followed:
downgrade to lollipop 5.0
install CandySIX Rom , then try to connect to my carrier network , at the first time it not give me anything , but when i reboot my phone , LTE appears and everything fine
back to CloudyG3 2.5 then i found that the problem resolved
My phone now works well

OKAY, i found a solution to the problem and here is what i found :
Pacote-san said:
Same here...
Edited: Fixed this deletings the folder LTEconfigs on System/app
Had to then configure it to auto GSM/WCDMA then switch back to LTE auto
It connected at first with 3g then it went LTE and worked normally
Click to expand...
Click to collapse
i made it and not i have no drop in connection and i am sure that i will receive the next important call from my colleges.
I hope that this help you as it helped to me!
All the best!

goly1993 said:
Still working with you? So it is sim card fault? With me after searching networks everything seems to be ok, but I couldn't connect with LTE. Only sometimes successfull connection.(once a day and after reboot same...) Very strange. :/
Click to expand...
Click to collapse
Some people got their phones back to normal by flashing some roms (like CM, ACIP, stock, etc.), but that didn't work for mine
not sure if it was sim card fault, but my problem solved (at that time i was back to LP stock 20h) after swapping my sim cards with my friend's.
i am still using that sim card at this moment, working fine since last thursday

Same problem here, have signal drops on MM roms with LTE connection.
Tried all methods above, nothing really helps .. ;((
The signal is fine on LP roms, tho i installed N&N so i was able to change network type to GSM/WCDMA auto, having steady signal now, but missing LTE speed, trying to find solution to fix this, but unfortunately for now.

Same, my G3 doesn't recognize my sim sometimes or it just loses signal randomly, making the smartphone almost useless.
I tried CloudyG3 2.5 Lollipop, then upgrading to Marshmallow with many radios flashed (also the hybrid one) , then I tried to come back to a stock Lollipop ROM and the signal is always unstable. I'm going crazy due to that. I'm starting to lose hope too.

I think I've tried every possible solution to the connectivity problems I've read since flashing 30b.
Freezing LteConfigs gave me more stability, but didn't solve the problem completely. Tried editing the build.prop to force LTE as preferred network type, this didn't change anything. Don't even know how many times I've changed my apn settings.
Tried every combination of modems possible: 21a/c modem with 30b rpm/tz, pure 21a/c, pure brazilian 20c, brazilian 20c with 30b rpm/tz and nothing. Changed sims multiple times, didn't work.
The only way to get a reliable connection is to limit the phone to 3G... but that isn't a solution since I pay for unlimited 4G. If I let the phone in auto mode, the instant it tries to connect I lose all connectivity and it would take up to 2 minutes searching for the network.
I'll flash the stock rom today and if it doesn't work I can safely say it should be a hardware problem.

soulstaker said:
I think I've tried every possible solution to the connectivity problems I've read since flashing 30b.
Freezing LteConfigs gave me more stability, but didn't solve the problem completely. Tried editing the build.prop to force LTE as preferred network type, this didn't change anything. Don't even know how many times I've changed my apn settings.
Tried every combination of modems possible: 21a/c modem with 30b rpm/tz, pure 21a/c, pure brazilian 20c, brazilian 20c with 30b rpm/tz and nothing. Changed sims multiple times, didn't work.
The only way to get a reliable connection is to limit the phone to 3G... but that isn't a solution since I pay for unlimited 4G. If I let the phone in auto mode, the instant it tries to connect I lose all connectivity and it would take up to 2 minutes searching for the network.
I'll flash the stock rom today and if it doesn't work I can safely say it should be a hardware problem.
Click to expand...
Click to collapse
I had exactly the same problems I tried all of the solutions mentioned modems/roms/etc but what solved it for me was flashing the Pure stock MM kdz now no signal drops or 4g problems.

tallman43 said:
I had exactly the same problems I tried all of the solutions mentioned modems/roms/etc but what solved it for me was flashing the Pure stock MM kdz now no signal drops or 4g problems.
Click to expand...
Click to collapse
Did you root after flashing the kdz? I'll try with pure 30B but having no root is almost as bad as no 4G.

soulstaker said:
Did you root after flashing the kdz? I'll try with pure 30B but having no root is almost as bad as no 4G.
Click to expand...
Click to collapse
No not rooted it yet, to be honest I don't like the kingroot app it looks way too suspicious to me + the rom is smooth and stable at the moment so I thought I would stick with stock for a while.
Sent from my LG-D855 using Tapatalk

You could take a look on this : http://forum.xda-developers.com/lg-g3/help/annoying-lg-g3-problem-lte-signal-solved-t3293721
This is my answer to this mass problem. Hope this help yo all you !

mccloud90 said:
You could take a look on this : http://forum.xda-developers.com/lg-g3/help/annoying-lg-g3-problem-lte-signal-solved-t3293721
This is my answer to this mass problem. Hope this help yo all you !
Click to expand...
Click to collapse
This worked for me after nothing else had. Thanks a lot!
Sent from my LG-D855 using Tapatalk

adamw said:
This worked for me after nothing else had. Thanks a lot!
Sent from my LG-D855 using Tapatalk
Click to expand...
Click to collapse
just say thanks into that thread and vote to be able to other members to be sure that this helps. I am so happy that this method helped you. HF

LG G3 4G Network Drops

So the problem I'm having with my G3 is that the Network either drops and comes back repeatedly or completely drops and does not return. This only happens on 4G. When I go into network settings and change network mode to 3G it works fine and I get a constant signal all the time.
I have been using Fulmics ROM and I thought maybe that was the issue. But it wasn't.
I tried 3 different sims from three different carriers (Three, EE, O2) on several stock firmwares. (20N, 21C, 30A, 30F).
Each scenario is the same; network drops when phone is on 4G network mode, but its fine on 3G mode.
However, I have noticed that if I leave Wifi OFF allowing 4G data to connect first, then its fine. I can even turn Wifi ON again and the network is stable. I can even turn Wifi and Data OFF and the network is still stable.
But, if I toggle aeroplane mode, where Wifi connects first or where Wifi and Data is turned OFF; I am back to the network dropping.
Also, I live in London UK so there should not be any signal issues. Can anyone tell me why this is happening. I doubt it's software issue as I've tried several firmwares.
Any help is appreciated.

Mate I'm afraid there is a high possibility it's the Fulmics ROM.. I'm still trying to read up on the issue myslef, there's a ton of reports in the Fulmics thread and around.

I'm using an UK bought LG G3 as well (from Three) and started experiencing similiar issues after I flashed Fulmics. Even tried rolling back to 4.4.2 using a .tot file but didn't really help me.
Still scouring all around trying to find how to fix the issue..

engmia said:
Mate I'm afraid there is a high possibility it's the Fulmics ROM.. I'm still trying to read up on the issue myslef, there's a ton of reports in the Fulmics thread and around.

I'm using an UK bought LG G3 as well (from Three) and started experiencing similiar issues after I flashed Fulmics. Even tried rolling back to 4.4.2 using a .tot file but didn't really help me.
Still scouring all around trying to find how to fix the issue..
Click to expand...
Click to collapse
Hmmm looking back now this issue did start when I first installed fulmics 3.5. But shouldn't everything revert back to stock when you reinstall stock firmware.

thufz9585 said:
Hmmm looking back now this issue did start when I first installed fulmics 3.5. But shouldn't everything revert back to stock when you reinstall stock firmware.
Click to expand...
Click to collapse
That's what I thought but I guess it's a little bit more tricky.
Anyways I think I managed to restore some kind of stability in the signal, still unsure about the process though. Seems that different stuff are working for different people. In a few days I hope to have some information to give you how to fix it.
In the meantime try checking the Fulmics thread for ideas and suggestions (that's where I start off from).

engmia said:
That's what I thought but I guess it's a little bit more tricky.
Anyways I think I managed to restore some kind of stability in the signal, still unsure about the process though. Seems that different stuff are working for different people. In a few days I hope to have some information to give you how to fix it.
In the meantime try checking the Fulmics thread for ideas and suggestions (that's where I start off from).
Click to expand...
Click to collapse
Yeah let me know when you find a fix. Really appreciate the help.
One thing that is sort of a temporary fix for me, works on Three, EE and O2 (only ones i tried), is connecting Data first when on 4G mode.
So if I toggle airplane mode and if Wifi connects first then the network drops or keeps refreshing.
But, if I leave Wifi OFF and Data establishes a connection; the network is stable and I can then turn Wifi On again and the network will remain stable.
I just have to make sure the network does not lose connection (i.e. tunnel or airplane mode), and if it does ensure Data connects first.
Also, another thing. After I reinstalled Fulmic 5.3 it seems 4G mode is sort of stable. As in when on 4G mode instead of dropping the network it connects via 3G automatically. But this only happens with Three.

thufz9585 said:
Yeah let me know when you find a fix. Really appreciate the help.
One thing that is sort of a temporary fix for me, works on Three, EE and O2 (only ones i tried), is connecting Data first when on 4G mode.
So if I toggle airplane mode and if Wifi connects first then the network drops or keeps refreshing.
But, if I leave Wifi OFF and Data establishes a connection; the network is stable and I can then turn Wifi On again and the network will remain stable.
I just have to make sure the network does not lose connection (i.e. tunnel or airplane mode), and if it does ensure Data connects first.
Click to expand...
Click to collapse
Okay here is what worked for me - open this guide and download the Three specifiic Lollipop and Marshmallow .kdz files.
Flash the stock Marshmallow firmware first using the LG Flash Tool method. Your phone probably won't automatically get recognized since you're running Fulmics now so you'll need to change the COM port as described in post #
After that downgrade to stock Lollipop using the LGUP method. Personally I downloaded more updated (I think, not sure) files from here.
Then I proceeded to re-root and clean install Fulmics 5.1 and the 5.2 and 5.3 OTA updates from recovery. Booted and network works without drops now with 4G connectivity.
thufz9585 said:
Also, another thing. After I reinstalled Fulmic 5.3 it seems 4G mode is sort of stable. As in when on 4G mode instead of dropping the network it connects via 3G automatically. But this only happens with Three.
Click to expand...
Click to collapse
I changed my carrier and got an automatic SMS with configuration for my phone and instructions to save it. I should've known something was fishy when I recieved the "congratulations for setting up" message even before I recieved the actual settings. Anyways 4G was running fine on my new carrier with 32 mbps speed which is okay, much better compared to the same carrier 3G network, however I only had 3 bars of connection so I gussed what the heck, I should save that configuration after all, it might make things better. What a bloody mistake. I lost 4G connectivity and my phone refused to connect to the 4G network, only 3G (just as you describe).
What worked for me in this scenario was wiping the cache and dalvik (not really sure this step is even necessary to be honest, but I was headed for a full rom re-wipe anyway and decided to try with this first), going into the hidden menu and choosing LTE only connectivity (Fulmics Tweaks -> Hidden Menu [or the hidden code for the phone app if you decided to stay on stock, which I dont have] -> Modem Protocol -> RAT Selection -> LTE only. At this step my phone got to the usual 3 to 4 bars of connectiviy but was displaying "Emergency mode only" and no data at all. I proceeded to Settings -> Networks -> More -> Mobile Networks -> Access point names -> Reset to default from the menu. If network mode doesn't change back to GSM/WCDMA/LTE auto automatically, change it back manually. At this point I had restored back my 4G connection and everything is working normally (30-32 mbps connection stationary in my house through a wifi hotspot next to my laptop).
Good luck, I would follow the steps as described just in case. I tried many reflashes before that should've worked but didn't for me. However different things work for different people, hope this works for you and please report back

engmia said:
Okay here is what worked for me - open this guide and download the Three specifiic Lollipop and Marshmallow .kdz files.
Flash the stock Marshmallow firmware first using the LG Flash Tool method. Your phone probably won't automatically get recognized since you're running Fulmics now so you'll need to change the COM port as described in post #
After that downgrade to stock Lollipop using the LGUP method. Personally I downloaded more updated (I think, not sure) files from here.
Then I proceeded to re-root and clean install Fulmics 5.1 and the 5.2 and 5.3 OTA updates from recovery. Booted and network works without drops now with 4G connectivity.
Click to expand...
Click to collapse
I'd like to thank you so much for this information! I was having signal drop issue after installing Fulmics ROM. Tried to flash stock ROM but no success. After doing the downgrade via LGUP method to LP my phone is getting full signal again (at least I didn't notice any drop until now).
Thank you!

waltertakashi said:
I'd like to thank you so much for this information! I was having signal drop issue after installing Fulmics ROM. Tried to flash stock ROM but no success. After doing the downgrade via LGUP method to LP my phone is getting full signal again (at least I didn't notice any drop until now).
Thank you!
Click to expand...
Click to collapse
Glad I could be of help!

engmia said:
Okay here is what worked for me - open this guide and download the Three specifiic Lollipop and Marshmallow .kdz files.
Flash the stock Marshmallow firmware first using the LG Flash Tool method. Your phone probably won't automatically get recognized since you're running Fulmics now so you'll need to change the COM port as described in post #
After that downgrade to stock Lollipop using the LGUP method. Personally I downloaded more updated (I think, not sure) files from here.
Then I proceeded to re-root and clean install Fulmics 5.1 and the 5.2 and 5.3 OTA updates from recovery. Booted and network works without drops now with 4G connectivity.
Click to expand...
Click to collapse
Sorry for the late reply.
I followed your instructions and unfortunately it didn't work. :crying:
I first tried with the D85520f you provided and then with an updated D85521C firmware. But nothing worked.
The temporary fix, which I found works, is to ensure 4G mobile data establishes a connection first before Wifi (turn Wifi OFF then ON after data established). Then there is no signal drop until I go through a tunnel or phone restarts (signal drops completely), which means again i have to ensure 4G mobile data establishes a connection before Wifi or else it'll go back to the constant signal dropping.
Guess I'll just stick with 3G at all times. I've spent too much time trying to correct this than actually finding enjoyment in using the phone.
Anyway really appreciate the time and effort you took to help with this annoying situation. :good::good::good:

thufz9585 said:
Sorry for the late reply.
I followed your instructions and unfortunately it didn't work. :crying:
I first tried with the D85520f you provided and then with an updated D85521C firmware. But nothing worked.
The temporary fix, which I found works, is to ensure 4G mobile data establishes a connection first before Wifi (turn Wifi OFF then ON after data established). Then there is no signal drop until I go through a tunnel or phone restarts (signal drops completely), which means again i have to ensure 4G mobile data establishes a connection before Wifi or else it'll go back to the constant signal dropping.
Guess I'll just stick with 3G at all times. I've spent too much time trying to correct this than actually finding enjoyment in using the phone.
Anyway really appreciate the time and effort you took to help with this annoying situation. :good::good::good:
Click to expand...
Click to collapse
Modem 21C should be your answer! Please try with that.

Is anyone still out there
engmia said:
Modem 21C should be your answer! Please try with that.
Click to expand...
Click to collapse
I flashed dummies and get dropped 4g data like this.
I have tot back to stock and didn't help... not Kdz
Haven't downgraded yet to LP yet.
On turborom now.
Can I just flash this modem? Have a link to the 21c modem?
Flash in twrp or send via LG flash?

[Q] WiFi stopped working.. Tried everything

I've done a lot of searching around here and couldn't find anything that could get my WiFi working again. A while back I was following a tutorial that would let me edit my network bands, but I could never get it to work.. Shortly after I noticed my WiFi stopped working. I'm not sure if it's a coincidence or not. Anyways, I've tried everything. I've used stock RUU's to flash it back to stock (erasing everything), installed different ROMs, Kernels, etc. I've noticed the WiFi will work shortly after a fresh install but after a bit it just stops. Turning it on will give a WiFi error followed by "settings has stopped working". I've even opened up my phone and made sure the antennas were connected correctly but that didn't do anything. My Bluetooth works just fine though!
I'm s-off and rooted

Helped one of my friend - installed latest firmware update, but he has phone without root and locked bootloader + s
-on

Where can I find the firmware update?

Did you try using a different SSID ?
Or did you verify the RUU flashes clean ?
Maybe your WiFi Chip is broken

LG G3(D855) Complete Signal Loss while Wifi is activated.

Hey guys,
i recently clean Updated from Fulmics 2.7 to latest 7.5. Everything worked fine until i suffered from Network completely droping while Wifi is active.
I tried different scenarios. The Bug is now reproducible.
1. LTE/3G/2G Auto Mode + Wifi >> Signal loss
2. LTE/3G/2G Auto Mode without Wifi active >> Signal stays active
3. 3G/2G Auto Mode + Wifi >> Signal stays active
4. LTE/3G Auto Mode + Wifi >> Signal loss
I tried almost every Modem available for the G3 in development section(21A,21C, Those hybrid types etc.). I tried different Roms now (Cloudy, Fulmics 7.0, ZOEs).
I made a clean install of the original Firmware (V30B via LGFlashTool). Reinstalled my Backup from Fulmics 2.7
Then i tried setting different APN Settings and tried messing around with LTE Bands in the hidden Menu. But nothing worked so far.
The Issue stays over all Roms and Firmwares and Modems and Fixes i tried
I really don't know what i can do now to fix this. Maybe s.o. got a Clue or Hint what else i can try.
The LTE function is essential for me because my Provider (O2 Germany) only builds LTE Networks and 3G got less coverage here.
The only thing i can imagine is that the SIM Card or the SIM Card Holder somehow got damaged??? The Card worked proper with Fulmics 2.7 for about 2 years now. Until the Update.
Thanks in advance
Bananaphone64

No one suffers from this?
Having Ressurrection Remix installed now and it works fine. So it has something to do with the Stock LG Rom?

Bananaphone64 said:
No one suffers from this?
Having Ressurrection Remix installed now and it works fine. So it has something to do with the Stock LG Rom?
Click to expand...
Click to collapse
I was having this problem on Fulmics rom but it was not total loss of signals. It keeps on connecting and disconnecting after few seconds. Stock works fine though.

I have the same problem. Using T-mobile lg g3 d855.
Trying to resolve still...