Develop Bugs

[Q] G3 / 20F No LTE?

Im using a D855 LG G3 running the bumped v20F stock firmware (see the android dev thread) with no issues except this one...
Im currently in singapore using a SIM card that supports 4G on a network that has good 4G coverage (M1) but i simply cannot get LTE/4G to work at all.
Ive tried the WCDMA/LTE/GSM/Auto in mobile settings and it always without fail sticks on "H". Via the hidden menu i select "LTE Only" and i get no data connection icon (or data) at all.
Searching the mobile networks ive tried manually selecting the M1 advertising as LTE on the list but the same thing - it defaults to "H" and wont shift off there.
The APN im using is the one advertised by M1 for 3G and 4G coverage.
I dont think this is a ROM problem hence posting it here but ive got no idea how to solve it. Anyone got any ideas what else i can do/change or check ?
Other than rooted, the stock ROM is not modified or customised in any way - it was a factory reset, clean install.

Similar issue in Argentina, with 20b on my D855. Tried using the 3845#855# code, selecting even the LTE only thing, but nothing, no LTE. SIM card and service is working right (tested on a Nexus 5).
Any thoughts would be appreciated.

alex_herrero said:
Similar issue in Argentina, with 20b on my D855. Tried using the 3845#855# code, selecting even the LTE only thing, but nothing, no LTE. SIM card and service is working right (tested on a Nexus 5).
Any thoughts would be appreciated.
Click to expand...
Click to collapse
Try reinstalling LTEConfigs.apk under system/app

Unfortunately, I can't root or flash anything on this phone until I know it can use our LTE bands, or should I return it. Any other way?

[Q] lg g3 d856 stucks in gsm mode

i have lg g3 dual d856
its official 5.01
now rooted
stock recovery
sim 1 has option for 4g 3g and 2g
sim 2 slot is for 2g only
i was using sim 1 for 3g and sim 2 for calls
but latter on i got some free 3g data on sim 2
i physically swapped sim slots of sims for using 3g of sim 2
now my sim 2 was in 4g/3g/2g slot of phone
and sim 1 was in 2g slot of phone
upon reboot i was unable to use 3g on sim one
while selecting manually error was shown that sim 2 is in wcdma mode ...
now mannual searching for networks in sim 1 only showing gsm signal
while sim 2 showing 3g networks
restart reboot nothing worked
factory reset solved the issue
but again upon swapping sims phone was stuck in gsm mode on both sim
again factory reset did the job .....
an y one else having this issue ?

Only work around is downgrade to kitkat....

commando0 said:
upon reboot i was unable to use 3g on sim one
while selecting manually error was shown that sim 2 is in wcdma mode ...
now mannual searching for networks in sim 1 only showing gsm signal
while sim 2 showing 3g networks
restart reboot nothing worked
factory reset solved the issue
but again upon swapping sims phone was stuck in gsm mode on both sim
again factory reset did the job .....
an y one else having this issue ?
Click to expand...
Click to collapse
I'm having the same issue. For me factory reset didn't fix it. However, now slot 2 runs 3g/4g while slot 1 is stuck in 2g, so I just put my data sim into the slot marked 2G (which now runs 3G/4G) and my other sim into the slot marked 2G/3G/4G (which now runs only 2G), and that works just fine. The 2G/3G/4G setting for slot 1 does nothing now, and there's no such setting for slot 2, but the latter is running 3G/4G anyway, so I'm ok with that.

msundman said:
I'm having the same issue. For me factory reset didn't fix it. However, now slot 2 runs 3g/4g while slot 1 is stuck in 2g, so I just put my data sim into the slot marked 2G (which now runs 3G/4G) and my other sim into the slot marked 2G/3G/4G (which now runs only 2G), and that works just fine. The 2G/3G/4G setting for slot 1 does nothing now, and there's no such setting for slot 2, but the latter is running 3G/4G anyway, so I'm ok with that.
Click to expand...
Click to collapse
which firmware are you on?
one work around is switch both sims to 2g then replace sim and re boot ....
factory reset while both sim are removed
but i think this issue is not present in official 6 update.

commando0 said:
which firmware are you on?
Click to expand...
Click to collapse
5.0.1 D85620b-CIS-XX it says, and update center says it's the newest.
commando0 said:
one work around is switch both sims to 2g then replace sim and re boot ....
Click to expand...
Click to collapse
Slot 1 is already stuck at "GSM only" and slot 2 doesn't have that setting at all, so not really sure how to do that.

download flash latest firmware LGD856 v20c from here
http://lg-phone-firmware.com/index.php?id_mod=41
back up your data ( all data will be erased )
remove sd card
remove both sims
flash it ( for guide search in forum )
after booting turn on phone use it for while and again factory reset it
now put both sims and it will be normal again i.e sim for 2g 3g and lte and sim 2 for 2g
one bug i have noted in v30b firmware that if we search mobile network in manually it will return error but auto network search will work normally

commando0 said:
download flash latest firmware LGD856 v20c from here
Click to expand...
Click to collapse
Is there some reason not to flash version V30C instead? Will I have a problem rooting it?
(Actually I seem to have lost root somehow in my current setup as well, I really need it back..)

Humm
For root i won't recommend it .....
Sent from my Redmi Note 3 using Tapatalk

Actually the thread is year old ...&
I have personally changed lg 3 ...
V30b was my last firmware ....
Rooting was not done
Only bug i came across was network manual search was returning error....
And battery drain was insane also ....
Rest was improved
Sent from my Redmi Note 3 using Tapatalk

I've installed crDroid running android 7.1.1 and now both my sim slots support 4G.

Network Signal Dropping after update to 6.0M (Poland)

When i bought D855p it came with 4.4, then i updated to 5.1, all official. After this i installed Cyanogenmod 12.1 and everything were fine. But when i installed 6.0(poland) my network signal keeps droping the intire day, it changes to UMTS and HSPA. I cant use my phone as a phone. The only way to solve this is, every time that i turn off the cel or put in airplane mode, is enter in MOBILE NETWORKS > NETWORK OPERATORS > SEARCH NETWORKS and choose GSM. (but i need to do this EEEEEVERY TIME that my cel turns off/airplane mode).
6.0 is the only ROM that i can choose GSM and the signal keep ~stable~. At least i can use my phone as a phone !
I did a backup of my IMEI before installing cm12 as well.
Things that i already tried :
-Flash ALL modem (ALL) , including 21C.
-intall cm13 and after cm12. Using TWRP 2.8 and 3.0.
-stock 4.4 , 5.0 , 5.1 and again 6.0. Using LGFlashTools
-MANY factory resets and wipes !
anybody can help me ? :good:

Same issue. I am on stock 4.4 and mobile network signal keeps dropping on weak signal area. I set to gsm/edge mode to mobile network. But nothing goes fine.

http://forum.xda-developers.com/lg-g3/help/lg-g3-4g-network-drops-t3394408#post67304224
Try this. However in your case download the Polad specific .kdz files

engmia said:
http://forum.xda-developers.com/lg-g3/help/lg-g3-4g-network-drops-t3394408#post67304224
Try this. However in your case download the Polad specific .kdz files
Click to expand...
Click to collapse
i'll try ! thanks

engmia said:
http://forum.xda-developers.com/lg-g3/help/lg-g3-4g-network-drops-t3394408#post67304224
Try this. However in your case download the Polad specific .kdz files
Click to expand...
Click to collapse
Doesn't work , sadly :crying:
i also tried to put in Network mode : GSM/WCDMA ( worked ) but when i choose GSM/WCDMA/LTE auto , signal drops every time. It is a solution to do this, but i cant use my LTE, and it sucks ...

Disable VOLTE n go to ur models service menu (check google) for me it was
*#546368#*851# (my model = d851)
*#546368#*XXX# (ur model=D8XX) verizon sprint numbers are differently
go to field test >network mode>set GSM permanently (try different gsm 850,990,etc)
Back > RAT selection > select GSM
U cant have network problems now cuz ur permanently set to gsm dont use 3g or 4g use wifi
hit like it helps

tevims said:
Doesn't work , sadly :crying:
i also tried to put in Network mode : GSM/WCDMA ( worked ) but when i choose GSM/WCDMA/LTE auto , signal drops every time. It is a solution to do this, but i cant use my LTE, and it sucks ...
Click to expand...
Click to collapse
I'm sad to hear that. Try also flashing modem 21C. There are also other guides for restoring your signal around the forum, different things seem to work for different people.

I Lost H+ now I have only 3g (H)

Some time ago, i updated my phone to 20h England via LGUP and i lost my H+ signal. The phone started to give only H (which is apprx. 8 Mbps speed). Before that I always had H+. Then i did factory reset, installed two different KDZ (which i used before). Yet, no H+ signal anymore. I deleted and reconfigured APN. Bu no chance... I tried my friends 4g sim card and it used 4g, but mine is a 3g+ sim card, so no 4g band for me. Do you know how to get H+ signal back? Shall i flash via TWRP, "system + boot + modem + bootloader" flashable zip files of 20A from http://forum.xda-developers.com/g4/development/stock-h815-20a-stock-images-kdz-t3232282 ? Can flashing modem zip file help? Do you have any advice?

bastab said:
Some time ago, i updated my phone to 20h England via LGUP and i lost my H+ signal. The phone started to give only H (which is apprx. 8 Mbps speed). Before that I always had H+. Then i did factory reset, installed two different KDZ (which i used before). Yet, no H+ signal anymore. I deleted and reconfigured APN. Bu no chance... I tried my friends 4g sim card and it used 4g, but mine is a 3g+ sim card, so no 4g band for me. Do you know how to get H+ signal back? Shall i flash via TWRP, "system + boot + modem + bootloader" flashable zip files of 20A from http://forum.xda-developers.com/g4/development/stock-h815-20a-stock-images-kdz-t3232282 ? Can flashing modem zip file help? Do you have any advice?
Click to expand...
Click to collapse
My lg g4 shows only H on 3g mode.I am getting upto 17mbps.

mine only gives 6-7 Mbps

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...