Develop Bugs

[Q] Samsung S3. No LTE after reboot

It is my first forum post and I believe I am posting it in the right section... I tried finding a similar problem to mine, but seemed to only find people that wanted to turn LTE off instead of on. The AT&T Galaxy S3 phone is rooted and I have gone between ics and jb roms and have gotten LTE to work every time. The problem is after I reboot the phone I lose LTE. I get 20+ up 10 down on LTE. After I loose LTE I get around 8 up 4 down.
I have tried.
1.) Re-installing a rom which gives me LTE until I reboot phone.
2.) I have tried installing modems from http://forum.xda-developers.com/showthread.php?t=1831898. If I have lost LTE after reboot, I can (9 out of 10) get LTE to work again after installing a modem. I lose it once I reboot the phone again though and am unable to flash a new modem to get LTE back to working and it won't unless I do 1.) again.
3.) I have made sure apn settings are on the correct pta lte setting. Usually most of the rom's have that already set to begin with.
4.) I have tried the *#2263# to change it to LTE. This WORKS and will reboot my phone into LTE everytime, but I lose being able to make phone calls, etc. From what I understand as well, I am unable to go to 3g/2g after settings LTE ALL and I don't want that either...
It is the only problem I have had with this phone. I notice a lot of times after I install a rom and reboot, it upgrades, and I lose LTE. I install a modem and get LTE back. I reboot phone normally without doing anything to the phone and it upgrades apps again and I lose LTE. That is the only conclusion I can come to as to why I lose LTE after reboot.

terminalerror said:
It is my first forum post and I believe I am posting it in the right section... I tried finding a similar problem to mine, but seemed to only find people that wanted to turn LTE off instead of on. The AT&T Galaxy S3 phone is rooted and I have gone between ics and jb roms and have gotten LTE to work every time. The problem is after I reboot the phone I lose LTE. I get 20+ up 10 down on LTE. After I loose LTE I get around 8 up 4 down.
I have tried.
1.) Re-installing a rom which gives me LTE until I reboot phone.
2.) I have tried installing modems from http://forum.xda-developers.com/showthread.php?t=1831898. If I have lost LTE after reboot, I can (9 out of 10) get LTE to work again after installing a modem. I lose it once I reboot the phone again though and am unable to flash a new modem to get LTE back to working and it won't unless I do 1.) again.
3.) I have made sure apn settings are on the correct pta lte setting. Usually most of the rom's have that already set to begin with.
4.) I have tried the *#2263# to change it to LTE. This WORKS and will reboot my phone into LTE everytime, but I lose being able to make phone calls, etc. From what I understand as well, I am unable to go to 3g/2g after settings LTE ALL and I don't want that either...
It is the only problem I have had with this phone. I notice a lot of times after I install a rom and reboot, it upgrades, and I lose LTE. I install a modem and get LTE back. I reboot phone normally without doing anything to the phone and it upgrades apps again and I lose LTE. That is the only conclusion I can come to as to why I lose LTE after reboot.
Click to expand...
Click to collapse
I am in the same boat as you. I can force LTE with *#*#4636#*#* and setting it to LTe only. But I lose phone calls and if I restart it goes back to WCDMA.

What rom are you using some roms don't have the late icon they have 4g instead. Also double check that you have the right lte apn enabled
Sent from my SGH-I747M using xda app-developers app

offwiththeface said:
What rom are you using some roms don't have the late icon they have 4g instead. Also double check that you have the right lte apn enabled
Sent from my SGH-I747M using xda app-developers app
Click to expand...
Click to collapse
Yea I realized that jb roms do not show 4g lte, they just show 4g. I check to see if I have LTE by doing going to the Settings->About Device-> Status and looking at Mobile network type... and/or a speed test as well.
I came from and tried these rom's
Year of The Dragon
Ariel.2.07 [2ETO][Aroma]
WanamLite Smooth,Stable & Battery
Right now I am on Stock TouchWiz Jelly Bean PORT (JellyBean 747 Milestone 3)
I have gotten LTE speeds on every single one of the roms until I reboot phone.

[Update- Best Solution So far]
I found that using the WanamLite Rom http://forum.xda-developers.com/showthread.php?t=1782732 enabled me to get LTE back fairly easy.
Everything is in the Settings->More Settings->Mobile Networks area.
1. I entered in a new Access point and just put Name: "pta" APN: "pta". You can fill out the rest like the MMSC, MMS proxy, etc but I did not need to.
2. Then went to Network Operators and waited for it to search for the networks (takes a minute or two). It showed up for me as two options being Maritime and AT&T. I selected Maritime and registered it. I was not able to register on AT&T and I don't even know what Maritime is. However,
3. I went to Network mode: Set it to GSM/HSPA/LTE(Auto mode). I get LTE every time.
Every time I reboot I can get LTE to work by doing steps 2.) and 3.) and is a little annoying, but better than having to flash a rom every time I reboot and lose LTE. I would like to try and find a solution though where I wouldn't have to do this every time I reboot.
[EDIT] There might be roaming charges, but by disabling Data roaming you should be fine. I believe you might incur charges if you try connecting to this network while on a cruise and have data roaming enabled. I have not done a lot of research on this so I could be wrong.

Cannot get LTE after flshing to CM10 (stable)

Hi all,
Newbie, first post here
Here's what I did:
1. Installed Samsung GS3 QCom ToolKit + samsung drivers
2. In the toolkit, successfully rooted phone (Flash Insecure Boot, CWM, Root phone + Install Busybox)
3. Installed ROM Manager from Market
4. Did a ROM backup with ROM Manager
5. Installed Cyanogen Mod: ROM Manager -> Download Rom -> CyanogenMod 10.0.0
After the ROM installed OK, I could not get "4G" icon to come up (I know that LTE="4G" icon). It would alternate between 3G/H/H+
I do know that my area has LTE, and stock ROM shows "4G"
Finally, I restored back to stock (rooted) from within phone using backup from step 4. The "4G" icon came back, so I know it's using LTE
Any ideas? I have tried wiping cache/dalvik, verifying correct APN settings for LTE.
I really want to go back to CM10. Thanks!

Set preferred network to LTE too and than restart your phone and it should work forever.
Sent from my SGH-I747 using xda app-developers app

the H stands for HSPA and the H+ stands for HSPA+
ATT refers to their HSPA and HSPA+ networks as "4g" which is why the stock rom showed that.... CM10 actually shows you to what type of network you are connected to.
Nothing has changed speed wise.. you are still connecting to the same old networks at the same speeds. Before it just said 4g no matter what.. now it shows exactly what its doing.

bazookaxxx said:
the H stands for HSPA and the H+ stands for HSPA+
ATT refers to their HSPA and HSPA+ networks as "4g" which is why the stock rom showed that.... CM10 actually shows you to what type of network you are connected to.
Nothing has changed speed wise.. you are still connecting to the same old networks at the same speeds. Before it just said 4g no matter what.. now it shows exactly what its doing.
Click to expand...
Click to collapse
So.. does that mean I never had LTE, even on the stock ROM?

that is a possibility.
on stock ROM, it would say 4G when you are connected to HSPA/HSPA+.
and then if you were on LTE, it would say 4G and 'LTE' underneath it.

mrhomiec said:
that is a possibility.
on stock ROM, it would say 4G when you are connected to HSPA/HSPA+.
and then if you were on LTE, it would say 4G and 'LTE' underneath it.
Click to expand...
Click to collapse
So I was driving around neighbohood in my town, and I noticed the "LTE" popped up on my stock ROM. Looks like it is indeed a coverage issue, even though map clearly shows that area has LTE

AOKP Task650- Signal/radio Problem

Hello XDA!
Hopefully im posting in the correct area of help;
Using a i747m factory unlocked - Im having a problem with my radio or carrier with the current ROM (AOKP(Jellybean 4.2.2 )Task650 (2.22.2013).
http://forum.xda-developers.com/showthread.php?t=1766684&page=1
When it was first installed fresh the signal would be full bar on the LTE network but still had to assign the LTE APN settings for Telus. now - it seems that the signal or similar is glitched? possibly? If i switch to 3G mode my signal is full (-70 or lower) where as when it get too LTE mode, living beside a hotspot i get between -99 and -120 before like i said was all working except data. (LTE was enabled working)
Ive gone through with my providers APN settings and all is correctly setup - Now with this - to connection with applictions are having a problem noticing that data is on the phone - even with Wi-Fi does the applications get numerous errors trying to receive data. It seems too now that seraching for networks will just also close out the options to do so and manually does it connect with a reboot as long as the APN is set.
anyone with ideas?
Edit: time stamps are also inconsistent ; i believe is why the applications are having issues too connect - unable to verify security certificates

Y3K89 said:
Hello XDA!
Hopefully im posting in the correct area of help;
Using a i747m factory unlocked - Im having a problem with my radio or carrier with the current ROM (AOKP(Jellybean 4.2.2 )Task650 (2.22.2013).
http://forum.xda-developers.com/showthread.php?t=1766684&page=1
When it was first installed fresh the signal would be full bar on the LTE network but still had to assign the LTE APN settings for Telus. now - it seems that the signal or similar is glitched? possibly? If i switch to 3G mode my signal is full (-70 or lower) where as when it get too LTE mode, living beside a hotspot i get between -99 and -120 before like i said was all working except data. (LTE was enabled working)
Ive gone through with my providers APN settings and all is correctly setup - Now with this - to connection with applictions are having a problem noticing that data is on the phone - even with Wi-Fi does the applications get numerous errors trying to receive data. It seems too now that seraching for networks will just also close out the options to do so and manually does it connect with a reboot as long as the APN is set.
anyone with ideas?
Edit: time stamps are also inconsistent ; i believe is why the applications are having issues too connect - unable to verify security certificates
Click to expand...
Click to collapse
http://forum.xda-developers.com/showthread.php?t=1831898&highlight=modem
You're welcome..
The link i gave is basically just a collection of modems for both i747m and i747.

amzi said:
http://forum.xda-developers.com/showthread.php?t=1831898&highlight=modem
You're welcome..
The link i gave is basically just a collection of modems for both i747m and i747.
Click to expand...
Click to collapse
THANK YOU! Re-flashed modem - All is smooth - +1 thanked.
now too fully enjoy this ROM goodness ^^

Fixed service dropping and locked LTE

I finally got LTE locked on with Telus other users confirmed Rogers, AT&T and Bell(thanks) . No service disconnections, even while on wifi.
The problem I see is conflicting settings while flashing roms/modems. This seems to be the only fix. I'm pretty stoked I figured this out because I was about to switch back to my s2x out of frustration.
This took a lot of trial and error, literally had nothing to go on and no where in particular to start. Enjoy.
MAKE SURE YOU ENABLE LTE TOGGLE IN ROM AND HAVE IT ON BEFORE STARTING.
1. Network mode(settings/wireless & networks, more/ mobile networks/ network mode) set to gsm/lte/wcdma
2.Phone setting in test mode *#*#4636#*#* set to lte/gsm
at&t / rogers should select gsm/lte/cdma in test mode
3.Recovery flash latest modem mumLL1
(at&t users flash ucdlk3)
Wipe cache/dalvik
4 . Reset. Give it a couple mins to ask the network for lte.
If you disable Lte(through toggle) and want to use 3g/H+ for battery saving, the only way I've been able to reconnect to it; is to re enable(toggle) and reset, wait a couple mins to connect.
Side note: depending on your 4g service area, it may bounce around 3g/H+ which is normal.
When you place a call it will drop to 3g (the believed reason for this is that the phone knows you won't need heavy data so falls back to ease up on the battery during calls) but will reconnect a couple mins later. Our phones are slow to negotiate Lte connections with the radio testing sockets and network stability before committing, so be patient.
Let me know if this works for you and which network. Thanks.
Modems can be found here
http://forum.xda-developers.com/showthread.php?p=34397816

Re: Fixed service droping and locked LTE
To check if it worked. Go into test mode and it should say Lte in network type.
Xda I747

So does this mean we get no 3g?
Sent from my Mind using Telekinesis!

Yes everything works. I can unselect lte in my toggles and it drops to 3g/hspa. When I re-enabled lte I noticed that I have to make sure in network settings lte/gsm/wdcma is selected and reset phone.
Xda I747

O wow lucky u I can't unselect on Att lol
Sent from my Mind using Telekinesis!

Which rom are you on? Should be up in your toggles. Basically it changes you network settings from cdma/gsm to lte/gsm/cdma. But it conflicts sometimes.
Xda I747

Its there it just doesn't do anything because all the modems on the Att S3 are Rill locked or something so we don't have the option to do it so easily
Sent from my Mind using Telekinesis!

dark_intel you are the man, i finally have 4G

btw works on at&t

countrylife said:
btw works on at&t
Click to expand...
Click to collapse
Just make sure you help spread this thread like a bad STD, this is a huge problem affecting many!

Worked for me on Bell Mobility.
Edit: Running CM10.1 (latest nightly)

No Test Mode using CM10.1 ROM
dark_intel said:
I finally got LTE locked on with Telus other users confirmed Rogers, AT&T and Bell(thanks) . No service disconnections, even while on wifi.
The problem I see is conflicting settings while flashing roms/modems. This seems to be the only fix. I'm pretty stoked I figured this out because I was about to switch back to my s2x out of frustration.
This took a lot of trial and error, literally had nothing to go on and no where in particular to start. Enjoy.
MAKE SURE YOU ENABLE LTE TOGGLE IN ROM AND HAVE IT ON BEFORE STARTING.
1. Network mode(settings/wireless & networks, more/ mobile networks/ network mode) set to gsm/lte/wcdma
2.Phone setting in test mode *#*#4636#*#* set to lte/gsm
at&t / rogers should select gsm/lte/cdma in test mode
3.Recovery flash latest modem mumLL1
(at&t users flash ucdlk3)
Wipe cache/dalvik
4 . Reset. Give it a couple mins to ask the network for lte.
If you disable Lte(through toggle) and want to use 3g/H+ for battery saving, the only way I've been able to reconnect to it; is to re enable(toggle) and reset, wait a couple mins to connect.
Side note: depending on your 4g service area, it may bounce around 3g/H+ which is normal.
When you place a call it will drop to 3g (the believed reason for this is that the phone knows you won't need heavy data so falls back to ease up on the battery during calls) but will reconnect a couple mins later. Our phones are slow to negotiate Lte connections with the radio testing sockets and network stability before committing, so be patient.
Let me know if this works for you and which network. Thanks.
Modems can be found here
http://forum.xda-developers.com/showthread.php?p=34397816
Click to expand...
Click to collapse
Ok sounds promising but unable to get my ATT phone running ROM cyanogenmod10.1 03/04 nightly into Test Mode using the keypad code provided. This does work for stock ROM phones. Do you know any other way to get into the test mode?

Haven't tried stock. Im on cm10..
Xda I747

I'm on CM10.1 not stock.
Sent from my SAMSUNG-SGH-I747 using xda app-developers app

Yeah I'm pretty sure everyone is using cm10 or aokp. Not sure if stock is having these problems. If they were I'd be on the phone yelling at Telus.
Xda I747

So let me get this right. This fixes the signal jumping around on cm10/aokp ROMs?? That's the only reason I stay on a stock based rom. I'm tired of seeing my signal jump back and fourth from 4g to 3g etc. On stock I always have a rock solid signal. It does not jump around..... Thanks in advance...
Sent from my SAMSUNG-SGH-I747 using xda app-developers app

Yes for me and others didn't even get 4g, also it would completely go out of service. Now I get steady 4g.
Xda I747

Any alternative way to get into "test mode" other than using the keypad?
Sent from my SAMSUNG-SGH-I747 using xda app-developers app

Sorry man, I tried looking around for a way. Could be the rom you're on. I know Liquid and Carbon are fine. Probably a couple more that I don't even know of, others have success with.
Xda I747

rpomponio said:
So let me get this right. This fixes the signal jumping around on cm10/aokp ROMs?? That's the only reason I stay on a stock based rom. I'm tired of seeing my signal jump back and fourth from 4g to 3g etc. On stock I always have a rock solid signal. It does not jump around..... Thanks in advance...
Sent from my SAMSUNG-SGH-I747 using xda app-developers app
Click to expand...
Click to collapse
stock lies to and shows 4G all the time, cm10 and show the truth. the s3 sets at 3g until data is needed then transfers to 4g

No LTE after rom install

I have a S3 i747 and have tried several different roms and always lose my LTE. After install it jumps back and forth between H+ and 3g it never stays on one. I have tried installing LTE fix and it does not fix problem. I also tried manually entering correct ATT setting but still nothing. I tried speedtest after to see what my speeds where and H+ is around 3mb download and 3g is around 500kb download. please can anyone help

khoury1 said:
I have a S3 i747 and have tried several different roms and always lose my LTE. After install it jumps back and forth between H+ and 3g it never stays on one. I have tried installing LTE fix and it does not fix problem. I also tried manually entering correct ATT setting but still nothing. I tried speedtest after to see what my speeds where and H+ is around 3mb download and 3g is around 500kb download. please can anyone help
Click to expand...
Click to collapse
Try this
http://forum.xda-developers.com/showthread.php?t=1947376

khoury1 said:
I have a S3 i747 and have tried several different roms and always lose my LTE. After install it jumps back and forth between H+ and 3g it never stays on one. I have tried installing LTE fix and it does not fix problem. I also tried manually entering correct ATT setting but still nothing. I tried speedtest after to see what my speeds where and H+ is around 3mb download and 3g is around 500kb download. please can anyone help
Click to expand...
Click to collapse
Do you still have your imei? That's located under settings, about phone, and phone status.
Sent from my SGH-I747 using Tapatalk 4 Beta

Yes it's to still there. I entered the correct settings from above post. And it still jumps from H+ to 3G
Sent from my SGH-I747 using xda premium

If that didn't fix try this
http://forum.xda-developers.com/showthread.php?t=1947376&page=27 Post: 263
mrnovanova said:
Yeah that happens when going back to a tw rom from an aokp. What you have to do is backup your current rom, restore a backup of your stock rom once you're in there go to more settings you should find the option for lte in there choose it wait for it to connect and once you're connected just restore you're rom and you should have lte.
Sent from my SAMSUNG-SGH-I747 using Xparent Cyan Tapatalk 2
Click to expand...
Click to collapse

khoury1 said:
I have a S3 i747 and have tried several different roms and always lose my LTE. After install it jumps back and forth between H+ and 3g it never stays on one. I have tried installing LTE fix and it does not fix problem. I also tried manually entering correct ATT setting but still nothing. I tried speedtest after to see what my speeds where and H+ is around 3mb download and 3g is around 500kb download. please can anyone help
Click to expand...
Click to collapse
Ok I can help you fix this no problem. First things first, do you have nandroid backup of your stock rom? You know that's the first thing to do before you flash right?
Carried by a Raven

Yes I have back up. I just restore phone and reinstalled rom still the same issue. Now H+ download speed .22mb

Can anyone help with this. I really want to try new Roms but don't want to lose 4g or LTE
Sent from my SAMSUNG-SGH-I747 using xda premium

This is slightly different than the guide posted above and has worked for me every time.
Go into your phone dialer. Enter *#*#4636#*#*. Go to phone information, and find the drop down menu. Select "LTE only". This should force LTE. Then you can select LTE/... Whatever one you want, and it should start connecting to LTE by default. If it didn't work, then LTE is unavailable to your phone for whatever reason.
Sent from my SGH-I747 using xda app-developers app

So if i am not in a LTE area will i still have 4g cause right now it bounces between H+ and 3g. it does not hold H+ very long then goes to 3g for few minutes then back and forth and download speeds are crap. I was getting .22MB.
Lumixz said:
This is slightly different than the guide posted above and has worked for me every time.
Go into your phone dialer. Enter *#*#4636#*#*. Go to phone information, and find the drop down menu. Select "LTE only". This should force LTE. Then you can select LTE/... Whatever one you want, and it should start connecting to LTE by default. If it didn't work, then LTE is unavailable to your phone for whatever reason.
Sent from my SGH-I747 using xda app-developers app
Click to expand...
Click to collapse

I tried to dail *#*#4636#*#* after rom install but nothing happens

khoury1 said:
So if i am not in a LTE area will i still have 4g cause right now it bounces between H+ and 3g. it does not hold H+ very long then goes to 3g for few minutes then back and forth and download speeds are crap. I was getting .22MB.
Click to expand...
Click to collapse
If you are not in an LTE zone, you cannot connect to it. If your phone says "4G", it is referring to LTE. "H+" refers to HSPA+ which is more accurately 3.5G. If your phone is switching between H+ and 3G, it may just be corresponding with your data activity, where H+ is active and 3G is inactive. It may also be because of poor connection, which could too be why you're getting bad download speeds.
khoury1 said:
I tried to dail *#*#4636#*#* after rom install but nothing happens
Click to expand...
Click to collapse
That's strange. Try downloading this app.
https://play.google.com/store/apps/details?id=net.andirc.lteonfoff