Develop Bugs

Can't get LTE + Network to work

Hey guys! I recently bought a G3. It's a Korean Variant LG-F400L from U+. My problem with this phone is that when set to "Global" mode (GSM/WCDMA/LTE) it connects to LTE but says "Not in Service Area" whenever I try to make a call so I don't get the normal call and text services but when I set my network mode to (WCDMA Only) I get the call and text service but no LTE only 3G. So maybe Global mode prioritizes GSM? I don't know.
If I do LTE only mode, I can receive texts I believe but I can't make phone calls. I know it is not a problem with my network, as I have a Galaxy Note 3 and LTE + Calls work fine on my Note 3. Yet this G3 will only do one or the other. There is no option from WCDMA + LTE only.
IF anyone has any ideas, I would love to hear it. I'm also wondering if changing the rom would help this issue.
I should also mention that I am on another provider (SK Telecom) while my phone is a unlocked U+ phone!

Metsuna said:
Hey guys! I recently bought a G3. It's a Korean Variant LG-F400L from U+. My problem with this phone is that when set to "Global" mode (GSM/WCDMA/LTE) it connects to LTE but says "Not in Service Area" whenever I try to make a call so I don't get the normal call and text services but when I set my network mode to (WCDMA Only) I get the call and text service but no LTE only 3G. So maybe Global mode prioritizes GSM? I don't know.
If I do LTE only mode, I can receive texts I believe but I can't make phone calls. I know it is not a problem with my network, as I have a Galaxy Note 3 and LTE + Calls work fine on my Note 3. Yet this G3 will only do one or the other. There is no option from WCDMA + LTE only.
IF anyone has any ideas, I would love to hear it. I'm also wondering if changing the rom would help this issue.
I should also mention that I am on another provider (SK Telecom) while my phone is a unlocked U+ phone!
Click to expand...
Click to collapse
Hi! I guess you're in Korea? Have you tried another sim card? Is this a new phone or did you purchase it second hand?
EDIT : It sounds like a network problem.. The phone hasn't been registered correctly.

Did you make sure you have the right APN settings?

So I actually changed my mobile provider to u+ because I was off contract and my phone was able to get VoLte and LTE. So maybe the issue was the phone defaulting to VoLte? I have no idea how to turn it off on this F400L model. I've tried most of the methods I think. Any ideas how to turn it off? Either way I guess it's a little bit solved now that I can call again.

I am having the same problem
Hello Metsuna
Can you tell me how you solved the problem, I am having the same problem and cant connect to internet. Can;t make or receive any calls.
Thanks

[Q] MetroPCS APN settings aren't working

Hello, I bought my zenfone 2(Z00AD) recently and tried to use the SIM card from my other phone which worked on every phone I have owned but oddly enough it will not work at all on the Zenfone 2. All that comes up is the signal bars and and x with no indication of bar signal. I can receive voicemail oddly enough but it will not call, receive calls, texts or data.
Can someone help me with this problem, I have tried many of the apns and it doesn't work.

Christopher876 said:
Hello, I bought my zenfone 2(Z00AD) recently and tried to use the SIM card from my other phone which worked on every phone I have owned but oddly enough it will not work at all on the Zenfone 2. All that comes up is the signal bars and and x with no indication of bar signal. I can receive voicemail oddly enough but it will not call, receive calls, texts or data.
Can someone help me with this problem, I have tried many of the apns and it doesn't work.
Click to expand...
Click to collapse
You have to call Metro PCS and give them your IMEI # so they can provision it onto their service. :good:

pctec919 said:
You have to call Metro PCS and give them your IMEI # so they can provision it onto their service. :good:
Click to expand...
Click to collapse
Alright, thank you, will do that tomorrow. Was a bit confused because in the past, just put the SIM card in and it worked.

No problem, I had to call my wife's in since she has Metro PCS.
I have At&t and it worked with just installing the sim card but my Speeds are under 9 Mbps D/L and 2 Mbps up

Stock Rom Carrier Unlocked not able to receive/send calls but can use data and SMS

Hey,
So I bought an LG G4 from Vodafone UK and unlocked it so i could use my Three sim card.
Weird thing is I can use Mobile Data and send/receive SMS if I am on 4G. The person who is calling me can hear the calling tone as if they were calling someone but I don't actually receive the call.
When I switch to 2G/3G it simply does not connect to the network.
I have done a factory reset and it did not fix the problem.
Any ideas?
Thanks
tl;dr : can't send/receive calls but can use data and send/receive sms (through 4G only)

radurock said:
Hey,
So I bought an LG G4 from Vodafone UK and unlocked it so i could use my Three sim card.
Weird thing is I can use Mobile Data and send/receive SMS if I am on 4G. The person who is calling me can hear the calling tone as if they were calling someone but I don't actually receive the call.
When I switch to 2G/3G it simply does not connect to the network.
I have done a factory reset and it did not fix the problem.
Any ideas?
Thanks
tl;dr : can't send/receive calls but can use data and send/receive sms (through 4G only)
Click to expand...
Click to collapse
Maybe you need to register your IMEI on the network? That's what I had to for At&t.

How would you go about doing that? Apart from manually searching for networks (I can see other carriers like O2, vodafone, EE, but I can't see my carrier Three ; the person living in the flat with me is on Three as well and they have no problem, so it's not a coverage issue. I have bought the phone from vodafone, unlocked it and trying to use it with Three).
Do I have to call Three for this IMEI registration or..?
Thanks

Hani88 said:
for me the battery is quite good
are you using V20B???
and did you do a factory reset after updating to MM ?
Sent from my LG-H815 using Tapatalk
Click to expand...
Click to collapse
Best bet will be calling your service prover and have them register it. I had to call At&t and have them register my IMEI since I couldn't use internet or make calls.

Just had a long chat over the phone with them and in the end he said the 'engineers' found a 'problem' on their end and it should be fixed in @5 days. He didn't want to mention what problem or how / why it happened. Oh well fingers crossed.
Thanks!

update : so after about 4 calls with customer service (across 3 weeks) and 2 trips to the 'Three' store i'm basically stuck and would need your help guys.
backstory : I've contacted them once at the start of January and they said they found the issue and they will fix it by 7th of January which didn't Happen. On 7th of January they said they are sorry and it will be fixed by 14th of January which didn't happen either. After that I received a message that the problem was fixed and if i had any other issues I should contact them, which I did because the problem was not solved. Yesterday I went to the shop again and the 'tech' guy told me that it should be working and he gave me a new sim card just to be sure, and if that didn't work he said call customer support and ask for contract cancellation. Today I got called by customer service and I have told them that it still doesn't work and I'm paying for something I can't use and I've been told to request contract cancellation which they didn't believe and said I have to pay the rest of the contract length in order to cancel, which is absurd. I went again to the shop and the new customer service person that was assigned to me said they don't have any tech people and she seemed she didn't believe when i said i talked to one the day before. She tested the sim on their phones and it worked and also she took my phone "in the back (strange cause she said they don't have any tech)" and said I had my phone set to 2G (which I didn't, it was set to 2G/3G) and that that was the problem. strangely, for that split moment i had one bar for 3g and the call went through. Straight after that phone stopped working (it was just that small area in which it worked). I told her that that's not the problem and she's like "welp you didn't make your contract at the store, you made it online so I can't help you , you have to call customer service". So I'm basically stuck with a contract which I can't use and I have no idea what to do.
problem : I cannot register to the Three network (only in small random areas, few of them) but I have no problems with other SIM cards from other Carriers (Orange, EE, Vodafone, O2). I have bought the phone from vodafone and unlocked it and last time customer service told me they can't give support to phones that were not bought from their store. So I'm stuck here with a phone contract which I can not use to make or receive calls, but I can use the mobile data and send receive texts. I am considering rooting it and puting a custom ROM , although I'm not sure if that would fix the problems (maybe issues with certain bandwiths?.
Any help or ideas much appreciated!

Same problem here
Hi all. Same problem here but different issue.
Origin : G4 buy used on November. IMEI fully working and not blacklisted (calling my french phone provider this morning, it tell me that's IMEI is ok and phone not stollen and it try to repair remotly my carrier but didn't work)
Problem : Fully working since i picked up a call and answer ... and then when the call is finish i tried to call someone 10 minutes after and totally loose signal(connection) (Orange/Sosh)
What i've maid before : Playing a lot @ a boring but adictive game. High temperature since 3 days because i play a lot but temperature decrease when i stop playing.
I've used a legal app to record a patern and make some actions without my intervention (RepetiTouch Free (root)) to make races in the game.
That's all ! No drop, no hit, nothing ! Just playing, having a call, hang off and then want to make an other call and nothing.
Since the last 6 hours : Signal ok - Data ok (can go on internet / GAPPS etc..) - CAN receive and send SMS (i've don't trie MMS) !!! but .... can't receive and can't send any call.
I was on Genesys 3.5 and i've update to 3.7 when i see the problem, believing that's it will fixe the issue but ... no ....
Formating and going to stock ROM but with root SU etc..... Can't receive and send call too ....
I'm going to back to stock with KDZ .... but i really believe that's it will not work .....
AND .... to finish and kill my joy .... i've unlock bootloader with LG tools since 2 month .....so my phone is no longer under warranty.
My SIM card work on others phones ... other sim cards didn't work in my phone ....
If anyone have this issue ... please tell us

Sorry bro cant help you here. Never heard of that problem before but my idea is that you should refund that phone back to Vodafone UK.

Phone stopped receiving and making calls

hi everyone, i have a lg G7 EMW for almost two years now. as said my phone its an EMW, although I use the EM variant ROM for more than a year because of the lack of updates. never had any issues before.
some weeks ago i had to make a call and noticed it was not working, at first i though it was a cover area issue with my carrier, since it was a place a little far away.
but in the following weeks i started noticing a lot of messages saying 'a number called you and did not left a message' and them i realised that the phone actually never ringed, so i started making some tests and realised it was not making or receiving calls.
i cannot acess all the settings in 'call settings menu' it return me an error saying "network or sim card error" but my 4G internet connection and SMS in the other way, works fine.
I already tried my SIM card in another phone, It worked normal. then i tried another SIM in my G7 and it has not worked also.
i have also tried to go back to my country open rom in a fresh install, but nothing changed.
yesterday after receive a cell broadcast notification, it worked for a short period an them stopped again, so i suspect may be some problem with the network, seems intermittent somehow
have any of you faced similar issue or know any solution? is there something i can do in service menu to see if its a hardware problem?

Storm927 said:
hi everyone, i have a lg G7 EMW for almost two years now. as said my phone its an EMW, although I use the EM variant ROM for more than a year because of the lack of updates. never had any issues before.
some weeks ago i had to make a call and noticed it was not working, at first i though it was a cover area issue with my carrier, since it was a place a little far away.
but in the following weeks i started noticing a lot of messages saying 'a number called you and did not left a message' and them i realised that the phone actually never ringed, so i started making some tests and realised it was not making or receiving calls.
i cannot acess all the settings in 'call settings menu' it return me an error saying "network or sim card error" but my 4G internet connection and SMS in the other way, works fine.
I already tried my SIM card in another phone, It worked normal. then i tried another SIM in my G7 and it has not worked also.
i have also tried to go back to my country open rom in a fresh install, but nothing changed.
yesterday after receive a cell broadcast notification, it worked for a short period an them stopped again, so i suspect may be some problem with the network, seems intermittent somehow
have any of you faced similar issue or know any solution? is there something i can do in service menu to see if its a hardware problem?
Click to expand...
Click to collapse
There were networking changes, so you need a sim card that is compatible with these changes.
If your SIM was purchased two years ago, it may not be compatible.
Just contact your phone provider, whoever it is, and ask them to sell you a compatible LTE Sim card. I had to buy one from Net10/Safelink for 99 cents, because the one I bought two years ago from Best Buy for "Net10" was not compatible with the new changes. All phone service providers should have a "buy your own sim" program, so just contact them for it.

check all necessary information in phone's settings about section.
Is any information missing there or blank?

Falkentyne said:
There were networking changes, so you need a sim card that is compatible with these changes.
If your SIM was purchased two years ago, it may not be compatible.
Just contact your phone provider, whoever it is, and ask them to sell you a compatible LTE Sim card. I had to buy one from Net10/Safelink for 99 cents, because the one I bought two years ago from Best Buy for "Net10" was not compatible with the new changes. All phone service providers should have a "buy your own sim" program, so just contact them for it.
Click to expand...
Click to collapse
i can give that a try but i'm not sure, my LTE and SMS seems to work normal, it is only the calls the problem.
the other SIM card i tested on my G7 was from a different carrier and the problem persisted
also my sim worked normal on other phone (Moto G5 Plus)

sourabh7625 said:
check all necessary information in phone's settings about section.
Is any information missing there or blank?
Click to expand...
Click to collapse
everything is showing up except from "My Phone Number" but that one never showed up before.
under Network, Status, Battery, Hardware Info tabs and etc it is also everything showing up

Storm927 said:
everything is showing up except from "My Phone Number" but that one never showed up before.
under Network, Status, Battery, Hardware Info tabs and etc it is also everything showing up
Click to expand...
Click to collapse
Call your carrier and ask them if they are using VOWIFI and VOLTE for their calls now.
The phone falls back to 3G mode on calls.
If the SIM or the tower you connect to is not provisioned for VOWIFI/VOLTE, the calls will use 3G.
if the tower is provisioned for VOWIFI but your SIM is not, then the calls will fail. SMS will not fail since that's LTE already.

Storm927 said:
everything is showing up except from "My Phone Number" but that one never showed up before.
under Network, Status, Battery, Hardware Info tabs and etc it is also everything showing up
Click to expand...
Click to collapse
This problem arises when particular phone has lost phone identification numbers such as S/N, IMEI SV and mainly IMEI. if it's the case then you must try flashing latest stock firmware for you model.

My LG G8 has lost signal but still recognize SIM card.

Hello everyone, my phone is LG G8 Korean SK telecom, i have been using my phone for over one and half years without mobile network problem, except its signal quite weak and the phone restarted frequently. Last week it suddenly lost signal (no signal at all, not rotating icon) though it still prompt me to enter SIM lock password. I had tried different ways like factory reset and even flash kdz to older and current Android version but nothing happened. Can anyone encountered this case help me ?

Hello,
No fix for you but I also have a lot of calling issues with my Korean G820N (LGU+). Most people calling me get the ringtone and my voicemail but I have NOTHING on the phone..... So, I miss calls and was forced to install a voicemail app to know if people called me or not....
I'm thinkign to flash a US KDZ but if you could give a quick feedback of your problem it could help me.