Hello there hope all of you doing well
i had Tmo SGH-T999 S3 which is unlocked but after unlocking its stuck on 2G Network i couldn't use 3g network
i search on google and i found this code :*#197328640#
but i don't know how to use it any way can you help me
wish best times 4 you ^_^
Did you sim-unlock the phone using a code?
I'm also having this issue. I have TMO SGH-T999 S3 sim unlocked before via software (not unlocked via code) and always stays on E (2G). I am thinking that i got messed up after the unlock. My IMEI is still intact btw.
First thing is to double check that your IMEI exactly matches the one on the sticker under the battery. If it checks out, the next best step is to reflash your current or newer stock firmware. (This can be caused by mismatched firmware so by flashing it you will either fix the problem or eliminate it as the cause).
You may also want to check your IMEI against the blacklists online. Especially if you bought it anywhere but a retail store.
Unlocking via code or secret menu should not affect radio bands available in the phone.
WCDMA Band preference
I've checked the WCDMA (3G) band preference available in my T999 S3 and below are the only option available:
The mode preference menu: *#2263#
The information menu: *#197328640#
WCDMA 850
WCDMA 900
WCDMA 1700
WCDMA 1900
WCDMA IMT2000
WCDMA ALL
... and found out my carrier band preference for 3G is 2100. Seems i'm out of luck for 3G data and since this T999 cannot support 4G LTE. I guess i'm stuck on E (2G) data unless i use WiFi.
P.S - Is there a way to add a 1800 or 2100 band preference to WCDMA? :fingers-crossed:
Check the General section in AT&Ts forum. They had something like this if I remember right. They could enable use on a different band, but I don't think it would stick after a reboot. It's been a long time since I looked at it though, so they may have made some more progress on it.
Goodbye 2G (E) data connection
I'm happy to report that my (WCDMA) data speeds is now functional on my SIM network carrier! :good: Loving the speed browsing at last . Although showing as 4G but i know my T999 is not capable of that and not very sure.
Again, thanks DocHoliday777 (I don't know how to link your name) for giving me the idea about the Modem mod. I just followed the guide on the link below and used the NV Data backup from T999L file. So for any users of T999 you can try this mod but please do it at your own risk and don't forget to backup.
I hope this T999L modem mod can be included on the newer root66 baseband/firmware so it can be permanent?
Anyway, just follow the guide on the link below and hit thanks!
http://http://forum.xda-developers.com/showthread.php?t=2344627
P.S - To access the modem setting on my SGH-T999 I've used the code *#0808#. And my final WCDMA setting i chose WCDMA ALL. Goodluck!
So i have an activated Verizon SIM that I was able to get semi-working on my OnePlus 3. Only data is working though. Calls and text don't seem to work.
I can only get service if I select "LTE" as my Preferred Network Type. I've tried multiple other combinations of GSM, LTE, CDMA, and WCDMA, and TD-SCDMA and none of them worked. Only "LTE".
I know this phone doesn't have the CDMA radio, but I feel like I should be able to get 3G or H+ on Verizon. Any suggestions on other Preferred Network Types to try? There's a ton of options, I've only had luck with LTE (and as I said, that was data only).
Is there a way to tell if I'm using a different antenna for the Verizon SIM? My main carrier is T-Mobile.
Bsanborn said:
So i have an activated Verizon SIM that I was able to get semi-working on my OnePlus 3. Only data is working though. Calls and text don't seem to work.
I can only get service if I select "LTE" as my Preferred Network Type. I've tried multiple other combinations of GSM, LTE, CDMA, and WCDMA, and TD-SCDMA and none of them worked. Only "LTE".
I know this phone doesn't have the CDMA radio, but I feel like I should be able to get 3G or H+ on Verizon. Any suggestions on other Preferred Network Types to try? There's a ton of options, I've only had luck with LTE (and as I said, that was data only).
Is there a way to tell if I'm using a different antenna for the Verizon SIM? My main carrier is T-Mobile.
Click to expand...
Click to collapse
I was a VZW user when I got the OP3 and I struggles with trying all the APN options even calling VZW to set some custom APN but nothing worked well. I never got LTE on 3g at best but point of ever having data and voice at the same time was no hope. With the frustration and VZW seeming to never ready go GSM I just moved over to ATT. I also have a TMobile account but only for house not my cell line.
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
HI there,
I brought my Robin to Toronto in July, but couldn't get data service however I tried. I did some brief googling on this, and found no answer. The 2G voice and SMS worked fine.
I have never had data problem in Canada in the past. I am on T-Mobile and previously LG V20, IPhone SE, Moto G4 Play, Galaxy S3, S4, S7 all worked fine in Toronto.
(trust me I tried all mobile setting options being an amateur android user for many years)
Any suggestions (other than APN setting etc that is user available in mobile data setting)?
Thanks!
Robin supports
GSM 850/900/1800/1900
HSPA 850/900/1700/1800/1900/2100
LTE Bands 1/2/3/4/5/7/8/12/17/19/20/28
Check which band your device is connecting to when you use your T-Mobile SIM.
There are many diagnostic codes but most are disabled for users to invoke.
But this one usually works,
Use *#*#4636#*#* > phone information > network type that is the band you are connected to.
If you aren't able to get info of the band you are connected to try apps like LTE Discovery or NetMonitor Cell Signal Logging.
LTE Band numbers are associated to certain frequency. Check [here](https://en.wikipedia.org/wiki/LTE_frequency_bands)
If the band you are connected to is indeed 3G/4G supported go to your carrier and ask them to get this working. Carriers usually have a whitelist of 4G devices which is how they determine which SIM is connected to which device and which network to provide.
If you try to change bands in the service menu (e.g. from Band 4 to band 2) and you have LTE but phone calls don't work at all (just says call ended instantly), just go to "network mode" and select automatic, which will get voice working again on your new band.
Turning the sim card off and back on won't fix that--that will just make the band reset to default (with voice working) which isn't want you wanted if you were switching bands.
This can be useful on low tier providers if one band is lagging horribly and another band is more reliable.
I just recently discovered the service menu, does this actually enable bands that normally aren't active? I see Band 71 here which I thought was only available on the TMobile US variant, yet here I am with the ULM model and it shows it in the menu. I'd like to enable it in case I'm ever in an area that supports it, but I'm not sure what this menu actually does?