Develop Bugs

[Q] Why Does my Korean N7100 think I'm roaming and not connect to mobile internet?

I bought my n7100 on taobao here in China, and it's a Korean version. I put my China Mobile sim card in, and it makes and receives calls, and text messages and can use wifi with no problem.
The only thing is the mobile data doesn't work. I rooted and tried tweakker, and HiNet, to reset my APN and MMS settings, but that didn't work. My phone still thinks I'm roaming.. it displays
this message "Data Roaming, You have lost data connectivity because you let your home network with data roaming turned off".
I've also tried updating the APN and MMS settings manualy with information i've found on the web.
I've googled and searched this forum and I can't find much. I thought it would be an easy APN settings fix but it seems not to be...
I took my phone in to the local China Mobile store they couldn't fix it. I took it to a local android expert here and they didn't know what to do.
Any ideas would be greatly appreciated.

If you bought a Korean Note 2, you don't (shouldn't) have an N7100. I also purchased one through Taobao.
You should have an SHV-E250S, E250L, or E250K. Which one do you have? Check the baseband version under Settings > About device page.
No matter what, you're going to be limited to 2G only with China Mobile.

You're right, It's SHV-E250S, and I'm fine using the 2g in China on China mobile, but I'd just like to know how..any help?
Baseband Version is E-250SKSVLJK

Try removing all modifications to your APN settings.
Next, go into Settings > More settings > Mobile networks > Network mode and change it to GSM only. Also make sure that Data roaming is not selected. Run a new scan for network operators while you're in there to refresh your APN settings to the right ones.

In data network mode I only have 2 options "3g only" or "LTE Preferred" I have it on 3g only. I have now unchecked data roaming, but I don't see any place to scan for network operators. I have included a few screenshots here, sorry i don't know how to insert them.. http://tinypic.com/r/2198djn/6 http://tinypic.com/r/24dhfmx/6 http://tinypic.com/r/2zof98w/6

Now it's obvious why you don't have data. Is this the stock Korean ROM? Are you rooted?
I can point you to a decent ROM that will fix all of this, provided you have the patience to fix it. It's relatively easy.

Yes it seems to be the stock Korean ROM. I am rooted using http://forum.xda-developers.com/showpost.php?p=31801060&postcount=2 I'm more than willing to flash another rom. I've put about 20 hours into this so far, I imagine I can muster enough patience to finish it

Once they give us a damn Korean Note II section, this kind of information will be a lot easier to find.
Try this ROM for now, it's the one I've been using for a few weeks and I love it.
Link source: http://koxda.com/thread-98683-1-1.html
ROM Download: http://pan.baidu.com/share/link?shareid=149494&uk=3355956772
Password: koxda.com

Thanks a lot the rom (715mb) is downloading now, I have tried to flash ROM's on my old galaxy nexus, and on this note II, but I never succeeded, can you please link me to a good guide, on how to flash this rom? thanks.

Odin is included in the download. If you're using Windows 7 you may or may not have the drivers for the phone, and can grab them out of the All-in-one Toolkit. Just installing the toolkit should install the drivers necessary.
http://forum.xda-developers.com/showthread.php?t=1923956
The ROM you're downloading has two files and two pictures, as well. Open the pictures and follow along. All you have to do is click two buttons, select two files, then hit start. It WILL wipe your phone.

I installed that rom you suggested, I went into settings and did GSM only, and had it automatically find my network (china mobile) selected it, rebooted, and still it says i'm roaming so there is no connectivity... any more ideas?

Can you try somebody else's SIM?
There's no reason you should not be getting service unless something is not right with your SIM or phone.

I installed the rom you suggested, i went into settings and made it GSM only, also had it automatically correctly locate my network (china mobile) and it said "registered on network".. but it still isn't working, same problem, it says no connectivity cus i'm roaming.. any ideas now?

my gf will be home from work in a couple hours, I can try her sim card then.. my sim card was cut by me for my old iPhone.. is it possible or likely that the phone can still make and receive calls, but that somehow data connectivity was affected by me cutting the card? also one guy at the phone fixing store tried his sim card (from another company) and internet worked fine he said..

dadroidda said:
I installed the rom you suggested, i went into settings and made it GSM only, also had it automatically correctly locate my network (china mobile) and it said "registered on network".. but it still isn't working, same problem, it says no connectivity cus i'm roaming.. any ideas now?
Click to expand...
Click to collapse
China mobile have various sim plans, from local to province to national. Are you using the sim in the same city in which you bought it? If not and you don't have a national plan, it could be why the phone is showing roaming. In China going from one province to another is already considered roaming unless you have a national plan. This is from my experience back 2 years ago. Also, you best check at a China mobile shop if you have data activated, gprs/edge is not activated by default, you need to ask them to do it.
I would advise you to switch to China unicom as they have 3g/hspa which is much faster than china mobile.
Sent from my GT-N7105 using xda premium

For clarfication, I am in Hainan, and the card is from hainan. I use the same sim card in my galaxy nexus without any problem. I tried my gf's card just now, it didn't say any problem with connectivity, and did not display roaming.. And it shows the G symbol (for 2 or 3 G I assume), and has up and down arrows next to it.. but it doesn't actually work for browsing the web or using apps over the data network.. I even reset all the APN settings and let it automatically find the China Mobile network, but it didn't help.. what if I try to set the APN settings manualy? and any other ideas??

Showing the G symbol is GPRS, which is 2G. You will not get 3G on the N7100, N7105, or Korean model Note 2 on China Mobile.
Sounds like you need a new SIM card. You can try to set the APN manually to make the data work with hers. I've never had to set an APN manually and I've used many phones here with all 3 carriers, so it's a bit odd to me. No clue why your card doesn't work, but since hers is working fine, it's definitely not your phone.

For the record, her card displayed G, but even after messing with settings, I couldn't get it to have working data network..
Today I bought a new card, and had it officially cut to size, put it in the note II and it's still telling me no data connectivity due to i'm roaming.. i'm so frustrated
edit: after restarting a few times and trying to automatically make it register on china mobile .. it worked on the 4th attempt.. it still displays data roaming, and I had to enable data roaming... but now it works, even though it says i'm roaming?? wtf

Ive the same problem with my Korean galaxy note 2 all voice service work perfect but when I tried to turn on data it says insert Usim Card to access network please help

3G Problems Non Sprint

Hi i'm not sprint user, i'm using different provider in my country
i have 3G all the time (doesn't have LTE here yet), voice call and sms working. But my 3G speed is really2 slow, somehow my speed is capped to 50kb/s normally i can get 200kb/s in my area. i have samsung s1 CDMA here with same provider and there's no problem. i ned patch for custom ROM but not with stock ROM
Some said that because sprint lock my EVDO if i'm using different carrier. The carrier provider here not to friendly so i cannot ask for their help :laugh: . is there any way to unlock that?
I Already tried ##RTN# and i have trouble to enable my voice call and sms , and i already tried to zero my EFS still no go
Doing a little research, my AN-AAA status is pending in DEBUG. I already tried LG service Menu to set "undetermined" but somehow the setting is not stick, after reboot, the 3 option there just blank are that normal? my parameter for data stick tough
APN modifying not helping, what ever i input i still have 3G
To be more clear i'm from indonesia, using smartfren carrier.
Maybe i can get more clue from you guys non sprint user. and helping other user :victory:
Thanks, and sorry for my bad english :angel:

Help 4g

Hello friend, i bought a new m9 and when i activate data mobile i have only 3g , i tryed factory reset, to setup my network,
I rooted my phone, installed custom room.. still no change.. anyone can know why ?

Well maybe you dont have great 4g signal in your area? Or change apn.

StyL3sX said:
Hello friend, i bought a new m9 and when i activate data mobile i have only 3g , i tryed factory reset, to setup my network,
I rooted my phone, installed custom room.. still no change.. anyone can know why ?
Click to expand...
Click to collapse
As stated already , the signal could be weak in your area. Type in the dialer key pad ##3282# and you can also look to make sure all the bands are enabled on your device. I don't see why they wouldn't be though. A handful of users have stated bad connectivity with the M9, but that's on the sprint network I have been reading about.

at ##3282# it say only OK.. nothing about enable bands and i tryed sim of my friend (vodafone 4g) he have m8 and 4g working... on my m9 doesnt..

StyL3sX said:
at ##3282# it say only OK.. nothing about enable bands and i tryed sim of my friend (vodafone 4g) he have m8 and 4g working... on my m9 doesnt..
Click to expand...
Click to collapse
I have same problem with my M9+. In Manchester Area UK
I had perfect 4G with my old M8 but with new phone only 3G!!
Let me know if you get any answers. HTC and Vodafone couldnt help me either.

Check access point names, make sure only one is listed and selected.
Go to networks and search for network, click automatic.
Open the connectivity selection and make sure that the scalable option is chosen (2g/3g/4g)
Are you using one Base with the wrong firmware? Make sure they match up.
Find a friend on the same network or shared network and see if they have 4g in your location.
Test the sim in another phone.
Call network to check for issues in your area and or if there is an error against your account, may need a new sim if that one is old.
Test in major parts of the city center next time you're shopping..
Perform a speed test to see what speed you're actually getting, hspa is up to 20mb, 4g AFAIK is around 60mb, I've had 48 before. Anything over 20 could be considered 4g, you will very very rarely see a 3G tariff go over 19mb, which is the most I've ever seen.
Good luck.

StyL3sX said:
Hello friend, i bought a new m9 and when i activate data mobile i have only 3g , i tryed factory reset, to setup my network,
I rooted my phone, installed custom room.. still no change.. anyone can know why ?
Click to expand...
Click to collapse
I have the same issue with the M9. Couldn't find an answer for this problem. Even tried opening lte bands as listed here but no luck.
The thing is that I used to get LTE where I am now, went on long holiday and can't get it to work again so no idea what's up.

Jhonys said:
I have the same issue with the M9. Couldn't find an answer for this problem. Even tried opening lte bands as listed here but no luck.
The thing is that I used to get LTE where I am now, went on long holiday and can't get it to work again so no idea what's up.
Click to expand...
Click to collapse
That's a network issue, get a new sim and speak with your provider. Try the things I listed too

dladz said:
That's a network issue, get a new sim and speak with your provider. Try the things I listed too
Click to expand...
Click to collapse
I tried my sim with my wife's iphone and i got 4g without any problem. It's not a sim issue. Whatever the problem is, it's with the device (hardware, software, settings). I remember it also took me a few weeks after getting the M9 to get a 4g signal, but then one day it just appeared so there's that to add to the mystery.

Jhonys said:
I tried my sim with my wife's iphone and i got 4g without any problem. It's not a sim issue. Whatever the problem is, it's with the device (hardware, software, settings). I remember it also took me a few weeks after getting the M9 to get a 4g signal, but then one day it just appeared so there's that to add to the mystery.
Click to expand...
Click to collapse
Reset your network settings mate, set to manual then back to automatic.
Make sure you actually catch the network on manual first before manual. You will find it, it's just a case of going through the motions.
Also click menu, reset to defaults in access point names.

dladz said:
Reset your network settings mate, set to manual then back to automatic.
Make sure you actually catch the network on manual first before manual. You will find it, it's just a case of going through the motions.
Also click menu, reset to defaults in access point names.
Click to expand...
Click to collapse
1. How do you "reset network settings"?
2. set to manual - you mean in 'Network operators' menu select 'Search networks', select my network, then go back and selecting 'Select automatically'?
3. What do you mean "just a case of going through the motions"?
4. Should I reset APN at the last step or at the beginning?
I'm trying to understand your steps as clearly as i possible can because this no 4g issue took a lot of time and effort from me and it still doesn't work. Any help is very much appreciated.

Jhonys said:
1. How do you "reset network settings"?
2. set to manual - you mean in 'Network operators' menu select 'Search networks', select my network, then go back and selecting 'Select automatically'?
3. What do you mean "just a case of going through the motions"?
4. Should I reset APN at the last step or at the beginning?
I'm trying to understand your steps as clearly as i possible can because this no 4g issue took a lot of time and effort from me and it still doesn't work. Any help is very much appreciated.
Click to expand...
Click to collapse
I am trying to help you.
There are no steps it's just a case of trying everything to do with the network. If what you say is true and you've literally just had this issue occur out of the blue then it has to be a difference on the handset, especially seeing as you have tested the sim in another phone and it works.
Reset to default is with apn, doesn't matter when you do this just reset them, make sure it's checked and cycle mobile data on and off.
Clarify that your device is set to 2g/3g/4g within network mode (I believe it's called)
And I was referring to setting network selection to manual within mobile network settings, then choosing your network, then researching and selecting automatic.
The path is: settings / mobile data / network operators / search networks, wait for yours and select it, cycle mobile data (turn off then back on) if that doesn't work, switch back to automatic.
Reboot your phone after making changes, perform the full shut down method instead of the restart or power off methods, it's power and volume up AFAIK, hold for 10+ seconds, might be 15.
Going through the motions refers to checking anything and everything which influences the network, one of these setting will get it working..
Might be seen as overkill but a factory reset (if it's not been tried already) good luck.

dladz said:
I am trying to help you.
There are no steps it's just a case of trying everything to do with the network. If what you say is true and you've literally just had this issue occur out of the blue then it has to be a difference on the handset, especially seeing as you have tested the sim in another phone and it works.
Reset to default is with apn, doesn't matter when you do this just reset them, make sure it's checked and cycle mobile data on and off.
Clarify that your device is set to 2g/3g/4g within network mode (I believe it's called)
And I was referring to setting network selection to manual within mobile network settings, then choosing your network, then researching and selecting automatic.
The path is: settings / mobile data / network operators / search networks, wait for yours and select it, cycle mobile data (turn off then back on) if that doesn't work, switch back to automatic.
Reboot your phone after making changes, perform the full shut down method instead of the restart or power off methods, it's power and volume up AFAIK, hold for 10+ seconds, might be 15.
Going through the motions refers to checking anything and everything which influences the network, one of these setting will get it working..
Might be seen as overkill but a factory reset (if it's not been tried already) good luck.
Click to expand...
Click to collapse
I know you are trying to help me, and I very much appreciate it. Truly am.
I tried doing all the steps you listed, but no luck. Even tried at some point to force lte only in 4636 screen but that resulted in no signal at all. Trying to manually select a network in that setting only gives me the other 2 networks that work in the area but not vodafone which is what I use.
As a complete overkill I RUU earlier to the new 2.11.617 firmware without signing into my google account or restoring anything, and still no lte. What I did saw however, in the select network screen, was that next to my network, it said 2g/3g and next to the other 2 networks here it said 2g/3g/4g. Obliviously I can't select them as it's a vodafone simcard.
I added here SS from LTE discovery app while i was on 'lte only' mode. You can see signal is there but it cannot connect.
Any wild ideas or suggestions? I'm opened to try almost anything

Just out of interest, have you tried a different sim card? I know you said that your sim worked in another phone but I'd still be tempted to contact voda to get a new sim and to see if everything is set up on a network level, you may have to tell via that the issue is persistent in different phones or they may make you pay for it.
Also, might be something to do with the association between your phone and your sim. I once had a sim that blocked my missus, she could call me but I couldn't call her, no active diverts of any kind, I could call anyone and they could call me, got a new sim and it was sorted. Very strange, but anomalies like this do occur.
Have you got any mods or are you at stock at the moment? I know you said ruu. Oh and lol click thanks BTW.

dladz said:
Just out of interest, have you tried a different sim card? I know you said that your sim worked in another phone but I'd still be tempted to contact voda to get a new sim and to see if everything is set up on a network level, you may have to tell via that the issue is persistent in different phones or they may make you pay for it.
Also, might be something to do with the association between your phone and your sim. I once had a sim that blocked my missus, she could call me but I couldn't call her, no active diverts of any kind, I could call anyone and they could call me, got a new sim and it was sorted. Very strange, but anomalies like this do occur.
Have you got any mods or are you at stock at the moment? I know you said ruu. Oh and lol click thanks BTW.
Click to expand...
Click to collapse
Well the thing is that my wife's sim card in my phone only gets 3g. On her iPhone it's 4g. My sim card in my wife's iPhone gets 4g. On my phone only 3g so it seems like a very specific problem with my device.
Shortly after ruu I installed viper 3.5 without any mods..
Can it be that my device is somehow blocked by the network towers or something of that nature?
Maybe a hidden setting somewhere that blocking the phone's 4g capabilities? This is getting ridiculous..
Thanks for your help mate. Can't believe I forgot to press the thanks button [emoji2]
Sent from my HTC One M9 using Tapatalk

Jhonys said:
Well the thing is that my wife's sim card in my phone only gets 3g. On her iPhone it's 4g. My sim card in my wife's iPhone gets 4g. On my phone only 3g so it seems like a very specific problem with my device.
Shortly after ruu I installed viper 3.5 without any mods..
Can it be that my device is somehow blocked by the network towers or something of that nature?
Maybe a hidden setting somewhere that blocking the phone's 4g capabilities? This is getting ridiculous..
Thanks for your help mate. Can't believe I forgot to press the thanks button [emoji2]
Sent from my HTC One M9 using Tapatalk
Click to expand...
Click to collapse
No worries fella
If you've already tried another sim and it's still not happening, the firmware matches the rom, your sim works in other phones with 4g. Then I'm really not sure mate..
Give Lee droid a whirl that's what I'm using at the moment.. A simple but great rom..
I'm pretty much out of ideas now, if all of the above has been checked then it's something that I'm not aware of.. Sorry mate..
for the record it is a weird one, something should have got it working by now..
---------- Post added at 12:58 AM ---------- Previous post was at 12:56 AM ----------
Are you in a position to be able to return the device? Just in case

dladz said:
No worries fella
If you've already tried another sim and it's still not happening, the firmware matches the rom, your sim works in other phones with 4g. Then I'm really not sure mate..
Give Lee droid a whirl that's what I'm using at the moment.. A simple but great rom..
I'm pretty much out of ideas now, if all of the above has been checked then it's something that I'm not aware of.. Sorry mate..
for the record it is a weird one, something should have got it working by now..
---------- Post added at 12:58 AM ---------- Previous post was at 12:56 AM ----------
Are you in a position to be able to return the device? Just in case
Click to expand...
Click to collapse
Thanks for the help mate.
I can't return the device as it was bought in the states and I live in Europe at the moment.
I think I will try to change my sim card for a new one just in case, and will change back to stock 2.11.617 for a couple of days to see if that can make any difference.
Will post an update if i will have one.

Jhonys said:
Thanks for the help mate.
I can't return the device as it was bought in the states and I live in Europe at the moment.
I think I will try to change my sim card for a new one just in case, and will change back to stock 2.11.617 for a couple of days to see if that can make any difference.
Will post an update if i will have one.
Click to expand...
Click to collapse
Good luck fella, hope it all works out for you. With it being bought in the states would the band frequency of the device make a difference? Just spitballing there. Good luck..

dladz said:
Good luck fella, hope it all works out for you. With it being bought in the states would the band frequency of the device make a difference? Just spitballing there. Good luck..
Click to expand...
Click to collapse
Yes it would. He probably bought a cdma and has to have the correct bandwidths unlocked.
Sent from a stolen (and crap) HTC M9

shivadow said:
Yes it would. He probably bought a cdma and has to have the correct bandwidths unlocked.
Sent from a stolen (and crap) HTC M9
Click to expand...
Click to collapse
Then that would make sense.

Network 4G, E okay, but no 3G..

Hi,
Anyone have any ideas on what the issue may be with my UK (EE) G4 ?
H815
Android 6.0(MM)
SW vers V20b-2340-30
Baseband Version - MPSS.BO.2.5.c3-00101-M8992FAAANAZM-1.31581.1
I get 4G no problem and 'E' (not sure about others) but cannot get 3G.
I think 4G is 2100 and 3G is 1800... would these be different chips in mobile so it's a hardware or aerial issue?
I've tried setting it to .2G/3G only' in normal Settings - and I get no signal.
I've also been in the test/etc menu [ accessed via *#LGMENU#*815# ]
. field test / mobile settings / Network Mode - and that's set to AUTOMATIC
. field test / mobile settings / RAT Selection - and that's set to GSM/WCDMA/LTE auto
Anything else I can look at / modify (of course mobile out of warranty a few weeks ago!)
I could try a factory reset it I have to or I could just blow the old EE -F/W and forget about it..
Just wondered if there was anything else I can look at/change quickly.
HISTORY:
I used to use wifi calling (EE signal at home non-existent) but after getting motherboard replaced (boot loop issue), I ended up with the 'standard' FW which doesn't have EE-Wifi extension.
As a result EE sent me an extender which doesn't work with my mobile as it's 3G specific(?).
My son can get calls through that so I know it's my phone that's at fault (in fact EE examined the log for my calls and said they can't see any recent use of 2G or 3G on my mobile at all).

kevcal said:
Hi,
Anyone have any ideas on what the issue may be with my UK (EE) G4 ?
H815
Android 6.0(MM)
SW vers V20b-2340-30
Baseband Version - MPSS.BO.2.5.c3-00101-M8992FAAANAZM-1.31581.1
I get 4G no problem and 'E' (not sure about others) but cannot get 3G.
I think 4G is 2100 and 3G is 1800... would these be different chips in mobile so it's a hardware or aerial issue?
I've tried setting it to .2G/3G only' in normal Settings - and I get no signal.
I've also been in the test/etc menu [ accessed via *#LGMENU#*815# ]
. field test / mobile settings / Network Mode - and that's set to AUTOMATIC
. field test / mobile settings / RAT Selection - and that's set to GSM/WCDMA/LTE auto
Anything else I can look at / modify (of course mobile out of warranty a few weeks ago!)
I could try a factory reset it I have to or I could just blow the old EE -F/W and forget about it..
Just wondered if there was anything else I can look at/change quickly.
HISTORY:
I used to use wifi calling (EE signal at home non-existent) but after getting motherboard replaced (boot loop issue), I ended up with the 'standard' FW which doesn't have EE-Wifi extension.
As a result EE sent me an extender which doesn't work with my mobile as it's 3G specific(?).
My son can get calls through that so I know it's my phone that's at fault (in fact EE examined the log for my calls and said they can't see any recent use of 2G or 3G on my mobile at all).
Click to expand...
Click to collapse
the biggest thing I tell people to look for is what ever carrier you are on make sure all the carriers bands support 2g 3g and 4g of device A lot of times this is a major cause. Of said issue. I run into this a lot using Verizons devices on AT&T

Well it used to work...
Maybe I'll do a complete factory reset to see if any software's affecting it...

kevcal said:
Well it used to work...
Maybe I'll do a complete factory reset to see if any software's affecting it...
Click to expand...
Click to collapse
That didn't make any difference..
Still stuck with no 3g or 2g access.
Guess from the lack of responses that it's likely to be a hardware fault..

..

the shield that covers SOC seems to be culprit for me, when I reseated that thing I was able to get some 3g connection compared to nothing.

Thanks, worth looking at

Either you changed your modem, or your provider is no longer using 3g
My provider is dropping 3g in certain areas in favour of 4g....so I'm not able to go back to 3g if the area already has 4g
Might not be answer your are looking for
But that's my 2 cents

Moved to Nougat and updated modem, no improvement. I Swapped networks (tried 3) and all the same problem so guess a hardware issue..
Just bought V30 so G4 will be my backup, so will live with it I guess.
Thanks for the ideas everyone.

LG G4 reception issue

I am having an issue with a phone I recently bought on eBay to replace my wife’s phone – a Samsung S3. After researching, I selected one that appeared to be compatible to our carriers’ network – AT&T. It’s a new factory unlocked LG G4 model US991 running Android 6.0 that arrived in a sealed LG box. I moved the sim card from the old phone to the new one, but I initially couldn’t get it to connect to our network. A call to AT&T customer service didn’t provide much help although they had me check the usual things when transferring a sim to a new phone. They advised to go to my AT&T store for help in getting it to connect. They were also unsuccessful after checking and verifying several things (not really sure what). They concluded that the phone must not really be unlocked as it was advertised.
Frustrated with that, I decided to try contacting the eBay seller about the issue and was happy to get a fairly quick reply, telling me to change the following network settings:
Select Mobile networks
Network mode – GSM/UMTS
GSM/UMTS settings
Network submode – Legacy 3GPP multi
Network operators – after choosing Search – found AT&T, RAT:WCDMA
And it worked - voice and texting both functioning well – and most importantly my wife was now happy. But it didn’t take long to realize the reception wasn’t nearly as good as my old Samsung S2 on the same network. We were in a rural location recently and where my phone was showing a decent signal, the G4 barely showed any and sometimes none. I also noticed that no matter where we were located, there was never an indication of a 4G connection in the home screen icons. So I then tried changing the network connections to the following that resulted in the 4G icon displaying but unfortunately voice and text stopped working completely (got an error message – no SIM card or SIM card error):
Network mode – LTE/CDMA
I also set the APN to NXTGENPHONE and its' settings according to the AT&T website
I’m hoping there’s something I can change to improve the connectivity/reception on this phone since my wife really likes everything else about it. I would appreciate any help/advice you could give.
Thanks

H815 TWN
in a rural the G4 H815 barely showed any and sometimes none Signal.
And the moto E showing a decent signal 4G and 3G.

Check out this thread: [FIX] US991 LS991 mobile data not working after Marshmallow update at: https://forum.xda-developers.com/g4/help/fix-us991-mobile-data-doesnt-t3356706 and see if the fix helps at all.
Confirm with AT&T that they tried one of their latest AT&T LTE capable sim cards to see if the issue is in the sim card you've been using. If not get them to try it.

bogen24 said:
I am having an issue with a phone I recently bought on eBay to replace my wife’s phone – a Samsung S3. After researching, I selected one that appeared to be compatible to our carriers’ network – AT&T. It’s a new factory unlocked LG G4 model US991 running Android 6.0 that arrived in a sealed LG box. I moved the sim card from the old phone to the new one, but I initially couldn’t get it to connect to our network. A call to AT&T customer service didn’t provide much help although they had me check the usual things when transferring a sim to a new phone. They advised to go to my AT&T store for help in getting it to connect. They were also unsuccessful after checking and verifying several things (not really sure what). They concluded that the phone must not really be unlocked as it was advertised.
Frustrated with that, I decided to try contacting the eBay seller about the issue and was happy to get a fairly quick reply, telling me to change the following network settings:
Select Mobile networks
Network mode – GSM/UMTS
GSM/UMTS settings
Network submode – Legacy 3GPP multi
Network operators – after choosing Search – found AT&T, RAT:WCDMA
And it worked - voice and texting both functioning well – and most importantly my wife was now happy. But it didn’t take long to realize the reception wasn’t nearly as good as my old Samsung S2 on the same network. We were in a rural location recently and where my phone was showing a decent signal, the G4 barely showed any and sometimes none. I also noticed that no matter where we were located, there was never an indication of a 4G connection in the home screen icons. So I then tried changing the network connections to the following that resulted in the 4G icon displaying but unfortunately voice and text stopped working completely (got an error message – no SIM card or SIM card error):
Network mode – LTE/CDMA
I also set the APN to NXTGENPHONE and its' settings according to the AT&T website
I’m hoping there’s something I can change to improve the connectivity/reception on this phone since my wife really likes everything else about it. I would appreciate any help/advice you could give.
Thanks
Click to expand...
Click to collapse
What is your signal strength on both Samsung and lg?
Download an app called advanced signal status on both phones
What is the db? And signal stength?
One should be a minus one should be a plus
They will also fluctuate so give me the number it usually sits at

deltadiesel said:
What is your signal strength on both Samsung and lg?
Download an app called advanced signal status on both phones
What is the db? And signal stength?
One should be a minus one should be a plus
They will also fluctuate so give me the number it usually sits at
Click to expand...
Click to collapse
Thanks, I'll try it and post back.

The results I got from the Advanced Signal Status app:
Samsung S2 - all entries showed n/a
LG G4 - Under GSM(2G/3G), RSSI was usually at -111 (5%), Signal strength was 1 db (3%)

sdembiske said:
Check out this thread: [FIX] US991 LS991 mobile data not working after Marshmallow update at: https://forum.xda-developers.com/g4/help/fix-us991-mobile-data-doesnt-t3356706 and see if the fix helps at all.
Confirm with AT&T that they tried one of their latest AT&T LTE capable sim cards to see if the issue is in the sim card you've been using. If not get them to try it.
Click to expand...
Click to collapse
The APN update did not appear to have any effect.
I'll go back to the AT&T store to verify the sim card as soon as I can.

bogen24 said:
The APN update did not appear to have any effect.
I'll go back to the AT&T store to verify the sim card as soon as I can.
Click to expand...
Click to collapse
OK - Thanks.
If your IEMI is not registered on their network (likely, as you didn't buy the phone from them), see if they will register it. May require that you buy a new LTE capable SIM card from them.
You may want to check out the first session in this link as well: https://recomhub.com/blog/fix-signal-problem-in-lg-g4/

bogen24 said:
The results I got from the Advanced Signal Status app:
Samsung S2 - all entries showed n/a
LG G4 - Under GSM(2G/3G), RSSI was usually at -111 (5%), Signal strength was 1 db (3%)
Click to expand...
Click to collapse
That is a very weak signal.
Here's the catch
Both phones should have displayed the signal strength
So you are using 2 different network bands on the phone
It's either your sim, or select another band on your LG G4
2G/3G that your phone is currently running on is an older network, and since your Samsung is not registered on that network you have selected wrong band on your LG G4 or your sim card is not compatible to operate on the network you want to be on

bogen24 said:
I am having an issue with a phone I recently bought on eBay to replace my wife’s phone – a Samsung S3. After researching, I selected one that appeared to be compatible to our carriers’ network – AT&T. It’s a new factory unlocked LG G4 model US991 running Android 6.0 that arrived in a sealed LG box. I moved the sim card from the old phone to the new one, but I initially couldn’t get it to connect to our network. A call to AT&T customer service didn’t provide much help although they had me check the usual things when transferring a sim to a new phone. They advised to go to my AT&T store for help in getting it to connect. They were also unsuccessful after checking and verifying several things (not really sure what). They concluded that the phone must not really be unlocked as it was advertised.
Frustrated with that, I decided to try contacting the eBay seller about the issue and was happy to get a fairly quick reply, telling me to change the following network settings:
Select Mobile networks
Network mode – GSM/UMTS
GSM/UMTS settings
Network submode – Legacy 3GPP multi
Network operators – after choosing Search – found AT&T, RAT:WCDMA
And it worked - voice and texting both functioning well – and most importantly my wife was now happy. But it didn’t take long to realize the reception wasn’t nearly as good as my old Samsung S2 on the same network. We were in a rural location recently and where my phone was showing a decent signal, the G4 barely showed any and sometimes none. I also noticed that no matter where we were located, there was never an indication of a 4G connection in the home screen icons. So I then tried changing the network connections to the following that resulted in the 4G icon displaying but unfortunately voice and text stopped working completely (got an error message – no SIM card or SIM card error):
Network mode – LTE/CDMA
I also set the APN to NXTGENPHONE and its' settings according to the AT&T website
I’m hoping there’s something I can change to improve the connectivity/reception on this phone since my wife really likes everything else about it. I would appreciate any help/advice you could give.
Thanks
Click to expand...
Click to collapse
I have several ideas for the reason of your problem. First of all, is everything ok with your SIM-card? Wasn't it damaged when you installed it in the new phone? Also your type of card can be not suitable for this certain phone model, unfortunately that happens sometimes
I'm really surprised that the customer service wasn't really helpful in your case, as I know they should check such cases personally in special centers and fix the tech problems. I recommend you to call them again and ask about this
And nice 4G connection demands a constant good signal. It's a rather common problem for the phones but not because of the bad networks but your current location, there are many places where this signal is very weak I had such problem in my house, I ended with buying a signal booster https://www.myamplifiers.com/4g-lte-booster/ which in my case was really helpful. However I suppose that your main problem isn't the signal but your phone, I think that you really need to check it in a special service center because all these problems mean nothing good for your device, especially the new one

I am merely speculating but depending on how old your last sim card is, it could just be as simple as getting (here in Canada they're like $5-$10) a new up to date one. It could also be an issue with the phone antenna itself?

Network mostly recovered
Just install advanced task manager from play store and set it to kill task every 15 min or so. Network issue will be gone. This is what worked for me. Thanks.

Bijoy414 said:
Just install advanced task manager from play store and set it to kill task every 15 min or so. Network issue will be gone. This is what worked for me. Thanks.
Click to expand...
Click to collapse
Could you tell me which task you have to stop. I have Task manager Show System Tasks selected and not sure which task is that?
Thank you
Greg

bogen24 said:
I am having an issue with a phone I recently bought on eBay to replace my wife’s phone – a Samsung S3. After researching, I selected one that appeared to be compatible to our carriers’ network – AT&T. It’s a new factory unlocked LG G4 model US991 running Android 6.0 that arrived in a sealed LG box. I moved the sim card from the old phone to the new one, but I initially couldn’t get it to connect to our network. A call to AT&T customer service didn’t provide much help although they had me check the usual things when transferring a sim to a new phone. They advised to go to my AT&T store for help in getting it to connect. They were also unsuccessful after checking and verifying several things (not really sure what). They concluded that the phone must not really be unlocked as it was advertised.
Frustrated with that, I decided to try contacting the eBay seller about the issue and was happy to get a fairly quick reply, telling me to change the following network settings:
Select Mobile networks
Network mode – GSM/UMTS
GSM/UMTS settings
Network submode – Legacy 3GPP multi
Network operators – after choosing Search – found AT&T, RAT:WCDMA
And it worked - voice and texting both functioning well – and most importantly my wife was now happy. But it didn’t take long to realize the reception wasn’t nearly as good as my old Samsung S2 on the same network. We were in a rural location recently and where my phone was showing a decent signal, the G4 barely showed any and sometimes none. I also noticed that no matter where we were located, there was never an indication of a 4G connection in the home screen icons. So I then tried changing the network connections to the following that resulted in the 4G icon displaying but unfortunately voice and text stopped working completely (got an error message – no SIM card or SIM card error):
Network mode – LTE/CDMA
I also set the APN to NXTGENPHONE and its' settings according to the AT&T website
I’m hoping there’s something I can change to improve the connectivity/reception on this phone since my wife really likes everything else about it. I would appreciate any help/advice you could give.
Thanks
Click to expand...
Click to collapse
Hey... I had this similar problem. I bought an Iphone 9 and and I had many problems with my signal. In many times, my cell phone showed "1 bar" of 4G, so I couldn't do almost anything. Fortunately, a friend told my about an signal booster and now my signal problems are done. I bought it in a website named amplificadordesenal.es and it's been really GREAT!! it cost a little but it was the better solution.
Hope this can help you