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[Q] FIDO Razr HD LTE problems!

Hello all -
New to Android platform. Hope someone from this great forum can assist ... I'll try to be brief. First, my device:
Razr HD LTE xt925
FIDO
Android v.4.1.2
Had attempted a little while ago to unroot my phone, as I was curious about better customization options. For various reasons, I tried to 're-root' and go back to factory. Did that, upgraded from ICS Jellybean 4.1.2 (which is what my phone was on when purchased).
Now, when I boot the phone, I still get the message 'Bootloader is unlocked'. After upgrading from ICS to Jellybean, I saw a large number of Verizon specific apps. When booting the phone, instead of the Motorolla 'M' icon/splash, I get a 'Droid' icon, with sound-effects. Also, System Version shows as 9.16.XT926.Verizone.en.US (even though my phone is an XT925 on FIDO). I obviously fudged something up... !
Most importantly, ever since, my GPS is very spotty, and I cannot get on the FIDO LTE network. In Mobile Networks setting, I have to always have 'Global' selected as network. If I choose LTE/CDMA or GSM/UMTS, it can never find an available network.
I'm really just trying to get my phone back to the state is was when I purchased it.
Any ideas would be GREATLY appreciated!

Canlin said:
Hello all -
New to Android platform. Hope someone from this great forum can assist ... I'll try to be brief. First, my device:
Razr HD LTE xt925
FIDO
Android v.4.1.2
Had attempted a little while ago to unroot my phone, as I was curious about better customization options. For various reasons, I tried to 're-root' and go back to factory. Did that, upgraded from ICS Jellybean 4.1.2 (which is what my phone was on when purchased).
Now, when I boot the phone, I still get the message 'Bootloader is unlocked'. After upgrading from ICS to Jellybean, I saw a large number of Verizon specific apps. When booting the phone, instead of the Motorolla 'M' icon/splash, I get a 'Droid' icon, with sound-effects. Also, System Version shows as 9.16.XT926.Verizone.en.US (even though my phone is an XT925 on FIDO). I obviously fudged something up... !
Most importantly, ever since, my GPS is very spotty, and I cannot get on the FIDO LTE network. In Mobile Networks setting, I have to always have 'Global' selected as network. If I choose LTE/CDMA or GSM/UMTS, it can never find an available network.
I'm really just trying to get my phone back to the state is was when I purchased it.
Any ideas would be GREATLY appreciated!
Click to expand...
Click to collapse
Here's the JB file for Fido/Rogers:
http://sbf.droid-developers.org/van...12.2_CANADA_VANQJBLTEFRCI_P004_CFC_fb.xml.zip

Thanks very much for your reply. I did try flashing with the FIDO file you quoted, and my phone didn't take it. I booted to fastboot, current drivers, and the RSD Lite message I got was:
Failed flashing process. 1/21 flash partition "partition_signed" -> Phone returned FAIL
The corresponding message on my phone was: Failed flashing process. 1/21 flash partition "partition_signed" -> Phone returned FAIL
Hope someone has an idea on how to successfully get back to the FIDO Android v.4.1.2.
Thank you all!

Have you removed the Getvar lines? You can also try the Telcel rom with Fido modem/fsg files placed into it. (That's what I had before custom roms because Fido was slow with JB).

Yes, I did try when removing getvar line in the xml.
I stated erroneously the error on my phone after trying the intitial FIDO flash - the phone error in fact was:
downgraded security version
update gpt_main version failed
preflash validation failed for GPT
I appreciate the input. Any other thoughts on this? I regret trying to unroot the damned thing in the first place... !

Canlin said:
Yes, I did try when removing getvar line in the xml.
I stated erroneously the error on my phone after trying the intitial FIDO flash - the phone error in fact was:
downgraded security version
update gpt_main version failed
preflash validation failed for GPT
I appreciate the input. Any other thoughts on this? I regret trying to unroot the damned thing in the first place... !
Click to expand...
Click to collapse
From what I can see, those errors come when trying to downgrade to ICS through RSD but you are trying to install JB so that makes no sense. Since you are bootloader unlocked you can probably flash the files through fastboot?

no worries man...calm down...you'll be fine...i had the same issue..i'm actually using an xt925 as well; had the same issue a couple of days back...see the issue is the ROMs that you see for xt925/926 is actually the ROM for verizon, so when you flashed a custom ROM, it actually flashed your GSM radio to the version radio, which is CDMA; These are the steps you need to follow, and you're good to go, trust me:
1). After deleting the getvar line, delete 2 lines below it as well, so lines 12 and 13, then try flashing with this new xml file. really imp, this will take about 5-10 mins, then the phone will reboot, dont unplug the cable yet, it's gonna reboot, and ask to sync phone with SIM, do that....and you're good to go.
2). Root.
3). Install TWRP, preferably 2.5, then backup your stockROM.
4). I would recommend using Matt's utility for xt926, and you can perform all the steps in sequence.
note: Since you unlocked your bootloader, you will always get that warning message, it's normal.
lemme know if it works!

eomahos I am in your debt. Worked like a charm!
In step 4 you indicated using 'Matt's utility for xt926' ... I'm not familiar with the utility. Do I use this to install TWRP?
Thanks again man!

[Q] 404 to 4.2 upgrade

I trying to find a working firmware for verizon s3 sch-i535 I have it unlocked using odin. T-Mobile [who I want to use]
confirmed my phone is unlocked but they can't connect because my firmware needs to be updated from 404. I went and tried
to get update but run into webpage not found Does anyone have direct download for updates.
Every site I go to is a big runaround. It can't be that complicated can it? Hope I get some help here. Thanks.

H779 said:
I trying to find a working firmware for verizon s3 sch-i535 I have it unlocked using odin. T-Mobile [who I want to use]
confirmed my phone is unlocked but they can't connect because my firmware needs to be updated from 404. I went and tried
to get update but run into webpage not found Does anyone have direct download for updates.
Every site I go to is a big runaround. It can't be that complicated can it? Hope I get some help here. Thanks.
Click to expand...
Click to collapse
T-Mobile = GSM
"This is not a GSM device, it will not work on any GSM network worldwide."
You can try whatever you want, the phone will only support carriers using CDMA
You can find every firmware that has been officially released at SamMobile

Thankyou. For getting back.I still want to upgrade the firmware 404 is old

H779 said:
Thankyou. For getting back.I still want to upgrade the firmware 404 is old
Click to expand...
Click to collapse
If you already checked SamMobile you saw that you can choose between:
4.1.2
4.3
4.4.2
There is no reason for not using KitKat 4.4.2
Once installed you can flash latest TWRP using ODIN and then flash SuperSU (For root access) using TWRP. Rott access is highly suggested to remove the bunch of bloatware coming with Samsung's firmware and for grant sd card r/w access for all your apps.

I knew that my phone is unlocked so I did a lot of reading and found that if I go into service mode and enable hidden menus that I could
go into mobile networks then choose other networks. There it is GSM! now the next window is a menu to choose band or all bands.
now I took the battery out and installed the T-Mobile Sim powered back up and get a message: Welcome to T-Mobile. Tried making a call
IT WORKS! TEXT ok Internet ok. This was all done while still running stock 404 firmware. I'm no andriod genius and don;t know why all
the posts I've read saying it can;t be done. All I did was use the advise you guys gave did the proper download to unlock and root.
This issue is resolved. Thank you!

H779 said:
I knew that my phone is unlocked so I did a lot of reading and found that if I go into service mode and enable hidden menus that I could
go into mobile networks then choose other networks. There it is GSM! now the next window is a menu to choose band or all bands.
now I took the battery out and installed the T-Mobile Sim powered back up and get a message: Welcome to T-Mobile. Tried making a call
IT WORKS! TEXT ok Internet ok. This was all done while still running stock 404 firmware. I'm no andriod genius and don;t know why all
the posts I've read saying it can;t be done. All I did was use the advise you guys gave did the proper download to unlock and root.
This issue is resolved. Thank you!
Click to expand...
Click to collapse
Gratulations! I was pretty sure its not possible, especially for verizon devices

Yes I was surprised but I am persistent. Drives my wife crazy! Feel free to share this with others.

[Q] Lost 4G after flashing another Stock

Hello guys.
I have a xperia Z3 from VIVO and flashed a rom from OI, everything went well on flashing the rom but after it finished i noticed that i lost my 4G. When i search for network there have a TIM BRASIL LTE but it won't let me register on it.
Do anyone know how to solve that?
Thanks!

Input the correct apn settings from your carrier

LitoNi said:
Input the correct apn settings from your carrier
Click to expand...
Click to collapse
Lito, do you think that would help?
Because the problem is that I am not able to register to the LTE network, it's not related to the ability of using internet.
Actually, this is exactly what happens, after i flash the firmware i have 4G but after a few minutes (Between 5 and 10 minutes) i completelly lose connection to the LTE network, even if it's available in the networks list.

Info
DiegoManBR said:
Lito, do you think that would help?
Because the problem is that I am not able to register to the LTE network, it's not related to the ability of using internet.
Actually, this is exactly what happens, after i flash the firmware i have 4G but after a few minutes (Between 5 and 10 minutes) i completelly lose connection to the LTE network, even if it's available in the networks list.
Click to expand...
Click to collapse
just test firmware of another region
(UK firmware for example)
:good:

DiegoManBR said:
Lito, do you think that would help?
Because the problem is that I am not able to register to the LTE network, it's not related to the ability of using internet.
Actually, this is exactly what happens, after i flash the firmware i have 4G but after a few minutes (Between 5 and 10 minutes) i completelly lose connection to the LTE network, even if it's available in the networks list.
Click to expand...
Click to collapse
Maybe if you explained a bit better that would?
Like mentioned before this post, try to flash only the baseband from another region, hopefully that will solve it.

Geeks Empire said:
just test firmware of another region
(UK firmware for example)
:good:
Click to expand...
Click to collapse
Geeks, there have no other region for my version of the Z3, also i am trying to flash many other rooms from my region and all of them results in a error during the flash... Blank error, no description.

LitoNi said:
Maybe if you explained a bit better that would?
Like mentioned before this post, try to flash only the baseband from another region, hopefully that will solve it.
Click to expand...
Click to collapse
Lito, thanks for the sugestion, i flashed the baseband for the Customized PT and after flash i got the 4G signal for about 30 minutes, but when i rebooted the phone, i completelly lost 4G again, and now in the network lists there is no LTE from TIM. Could it be because i installed an european baseband on a mobile here in brazil?
Thanks agian.

DiegoManBR said:
Lito, thanks for the sugestion, i flashed the baseband for the Customized PT and after flash i got the 4G signal for about 30 minutes, but when i rebooted the phone, i completelly lost 4G again, and now in the network lists there is no LTE from TIM. Could it be because i installed an european baseband on a mobile here in brazil?
Thanks agian.
Click to expand...
Click to collapse
thats weird... are you sure you have the correct APN settings inputted? Also, i would assume youve tried flashing the VIVO's baseband or any other USA roms?
Try the following if you have already done all those: go to dial pad and input *#*#4636#*#* > phone info > menu top right > select radio band > try Australia or USA or what ever pops up > scroll down and make sure LTE/GSM auto is selected or try out the other ones > scroll back up and hit the "run ping test"
if all these doesnt work, i would advise you to go back to the original rom.
just curious, which model number is your Z3?

LitoNi said:
thats weird... are you sure you have the correct APN settings inputted? Also, i would assume youve tried flashing the VIVO's baseband or any other USA roms?
Try the following if you have already done all those: go to dial pad and input *#*#4636#*#* > phone info > menu top right > select radio band > try Australia or USA or what ever pops up > scroll down and make sure LTE/GSM auto is selected or try out the other ones > scroll back up and hit the "run ping test"
if all these doesnt work, i would advise you to go back to the original rom.
just curious, which model number is your Z3?
Click to expand...
Click to collapse
Lito, now i will complicate a little bit more then. First, the model number of my mobile is D6646 from Brazil with DTV.
Also, i tried to flash the Vivo Baseband and it was worse, i did not install any baseband from USA, just from Portugal.
I tried that on the keyboard, but when i chose USA band i just can't even register on any TIM network.
Also, i tried to flash the original rom, but i can't flash any other firmware apart from Oi. I get a blank error line on flashtool for every other rom i tried to install, so it's even worse
Feel the challenge.
Thanks again for all your help.

flash back to the original ROM if you can, also, how did you flash to the new rom? through recovery or Flashtool? if you see a blank space or what ever, you might not have the correct drivers installed on your computer, especially if youre running Windows 8.
that being said, i dont see D6646 in Xperifirm, i cant tell you what to flash and what not to flash. Without that, i wouldnt advise you to flash anything but the original rom that it came with, you dont want to soft/hard brick the device.

LitoNi said:
flash back to the original ROM if you can, also, how did you flash to the new rom? through recovery or Flashtool? if you see a blank space or what ever, you might not have the correct drivers installed on your computer, especially if youre running Windows 8.
that being said, i dont see D6646 in Xperifirm, i cant tell you what to flash and what not to flash. Without that, i wouldnt advise you to flash anything but the original rom that it came with, you dont want to soft/hard brick the device.
Click to expand...
Click to collapse
Lito, I tryied to flash the original room, I am using XperiaFirm to download the firmware and flashtool to flash. I can flash the Oi room, but i can't flash the vivo BR, the Claro Argentina, or the Customized PT, all of them results in a blank error, it's not drivers problems, since i can install the Oi firmware and also i disabled the signature on windows in order to install.
Anyway, i solved the problem in order to show another problem. Here is the situation:
I created another APN to use when i don't want to use internet because even with data package disabled my mobile send data to the carrier that charges me, when i deleted that APN the 4G worked perfectly, but now my carrier is charging me the data . Any idea how to block this data comsumption?
Thanks again.

DiegoManBR said:
Lito, I tryied to flash the original room, I am using XperiaFirm to download the firmware and flashtool to flash. I can flash the Oi room, but i can't flash the vivo BR, the Claro Argentina, or the Customized PT, all of them results in a blank error, it's not drivers problems, since i can install the Oi firmware and also i disabled the signature on windows in order to install.
Anyway, i solved the problem in order to show another problem. Here is the situation:
I created another APN to use when i don't want to use internet because even with data package disabled my mobile send data to the carrier that charges me, when i deleted that APN the 4G worked perfectly, but now my carrier is charging me the data . Any idea how to block this data comsumption?
Thanks again.
Click to expand...
Click to collapse
that is extremely weird, never had such issues with any of my android phones. make sure data roaming is not on, the carrier shouldnt be able to charge you if you disabled data
Also, make sure the FTF files youve made with xperifirm and flashtool are correct, like not including the TA files etc..., i would advise you redownload those FTF files and try again, also make sure you have the latest flashtool available.
at this point, you are probably better seeking for a developer or someone who can read codes, make a logcat and see if the flashtool thread is available and ask there. Aside from the FTF files, you are better off asking the carrier why they are still able to charge you in such way. Sorry man, this is as far I can aid you in this matter. GL bud!

i have lost my 2g/3g network is slot 1

My first sim is only support 4g network, and second sim working perfectly with all network.
My device Lenovo p2a42
I think I lost GSM/UMTS band
I accidently click the United States band on *#*#4636#*#*
I a currently on marshmallow
I do all the factory reset setting but the problem is still,

I've own several devices and there's always a guy messing with their bands and that service menu and lost something I wonder why?
Good luck
Sent from my ONE A2005 using Tapatalk

salmanvts said:
My first sim is only support 4g network, and second sim working perfectly with all network.
My device Lenovo p2a42
I think I lost GSM/UMTS band
I accidently click the United States band on *#*#4636#*#*
I a currently on marshmallow
I do all the factory reset setting but the problem is still,
Click to expand...
Click to collapse
If your bootloader is still locked, have u tried flashing the fastboot image? There are instructions provided in some of the thread in the P2 section so u can try that. Note though that this is for the global version of P2... So the P2 that is linked to the service provider like Three in the UK might not be compatible (Volte might not work for example)

My problem is solved [SOLVED]
My device problem is solved
I update to nought using computer via adb commands
Note:-ota update canot solved my problem, i manully download the stock rom and flash through adb
****Thanks for All*********

salmanvts said:
My device problem is solved
I update to nought using computer via adb commands
Note:-ota update canot solved my problem, i manully download the stock rom and flash through adb
Click to expand...
Click to collapse
I have exactly the same problem with the 2G/3G on slot 1.
Could you write here in a little more detail the steps you followed in order to solve the problem?
For example, what stock rom, downloaded from where, what procedure through adb etc.
Thanks in advance

For me. Sim1 lost 2G but 3/4G is ok.

botson71 said:
I have exactly the same problem with the 2G/3G on slot 1.
Could you write here in a little more detail the steps you followed in order to solve the problem?
For example, what stock rom, downloaded from where, what procedure through adb etc.
Thanks in advance
Click to expand...
Click to collapse
I will tell you the solution
i am in marshmallow and i download the stock Rom with a web site
http://www.mediafire.com/file/no35yqbt5ssj5b2/Lenovo_P2a42_S233_20170404.zip
1. Download the Rom file to PC And Extract it
2. install your USB driver to PC (it automatically install your when your device connected)
3.enable USB debugging under developer option or USB settings
4.When USB debugging is on your phone will come a popup and allow the prompt
5.switch off your device and press volume- and Power Button and it will enter to fast boot mode
6. open the extracted folder in your PC and there is firmware folder open and there is a file flashall click and run the file
7. it will automatically run all the command
8. after completing your device restart automatically and update was complete
After that my Problem is Solved

Thank you for the detailed steps.
I'm not in Marshmallow though but in Nougat S233.
I hope that re-flashing the stock S233.zip to the already present S233 with this method will work

salmanvts said:
I will tell you the solution
i am in marshmallow and i download the stock Rom with a web site
http://www.mediafire.com/file/no35yqbt5ssj5b2/Lenovo_P2a42_S233_20170404.zip
1. Download the Rom file to PC And Extract it
2. install your USB driver to PC (it automatically install your when your device connected)
3.enable USB debugging under developer option or USB settings
4.When USB debugging is on your phone will come a popup and allow the prompt
5.switch off your device and press volume- and Power Button and it will enter to fast boot mode
6. open the extracted folder in your PC and there is firmware folder open and there is a file flashall click and run the file
7. it will automatically run all the command
8. after completing your device restart automatically and update was complete
After that my Problem is Solved
Click to expand...
Click to collapse
It's work. thank you very much.

There is another way to solve this problem
[emoji732] some user reported this methode in unlocked boot loader device may be cause lost imei, make a twrp backup completely and proceed, other wise try the first methode [emoji732]
Resetting the modem information through fastboot
1. Enter Fastboot Mode
2. Type the Command
fastboot erase modemst1
fastboot erase modemst2
fastboot reboot
Dont worry , the erase command , it will reset the modem and reolve network issues (accedently change band issue)
:good:

salmanvts said:
There is another way to solve this problem
Resetting the modem information through fastboot
1. Enter Fastboot Mode
2. Type the Command
fastboot erase modemst1
fastboot erase modemst2
fastboot reboot
Dont worry , the erase command , it will reset the modem and reolve network issues (accedently change band issue)
:good:
Click to expand...
Click to collapse
This all for locked bootloader.....I too face this issue and my bootloader is unlocked.
As soon as I hit erase modemst1,st2 on unlocked bootloader device...I will loose signal and can be everything related to IMEI.
Sad thing with unlocked bootloader P2 is fastboot flashing don't flash modem. There me be some fix process for unlocked bootloader.
For bootloader locked anything people do is a solution.
Also its not necessary to delete modemst1,st2.
Just reflashing stock will fix.

Chek the first methode it will work sure

salmanvts said:
Chek the first methode it will work sure
Click to expand...
Click to collapse
4g only sim1 signal Problem is bcz *#*#4636#*#* mode selected to United states....Lenovo stock has U.S option only. If someone select united states then sim1 is stuck to 4g mode.
*#*#4636#*#*
Lenovo Stock ROM has only mode option: United states.
Custom ROM has 2 modes: Automatic and united states as options. Selecting Automatic fix sim1 4g only issue.
Solution for different users:
---------- Post added at 12:31 PM ---------- Previous post was at 12:16 PM ----------
salmanvts said:
I will tell you the solution
i am in marshmallow and i download the stock Rom with a web site
http://www.mediafire.com/file/no35yqbt5ssj5b2/Lenovo_P2a42_S233_20170404.zip
1. Download the Rom file to PC And Extract it
2. install your USB driver to PC (it automatically install your when your device connected)
3.enable USB debugging under developer option or USB settings
4.When USB debugging is on your phone will come a popup and allow the prompt
5.switch off your device and press volume- and Power Button and it will enter to fast boot mode
6. open the extracted folder in your PC and there is firmware folder open and there is a file flashall click and run the file
7. it will automatically run all the command
8. after completing your device restart automatically and update was complete
After that my Problem is Solved
Click to expand...
Click to collapse
For bootloader locked you can do anything to fix. Flashing anything can fix it. Bcz fastboot flash can rework modem. Everything is a fix.
For bootloader unlocked devices fastboot don't flash modem files. Only way is to install custom ROM...Dail *#*4636#*#* and selecting Automatic and restarting the device fix sim1 4g only error.
*#*#4636#*#* U.S settings problem stays even user updates from S062 to S244 via OTA. Like IMEI stays this setting to stays.
Never hit erase after unlocking bootloader in future for any signal or modem reasons. This lenovo p2 can screw your Android experience
---------- Post added at 12:39 PM ---------- Previous post was at 12:31 PM ----------
salmanvts said:
Chek the first methode it will work sure
Click to expand...
Click to collapse
Never suggest without knowing everything completely. You know and seen one side of a coin. P2 will show you real stars if you ever tried to erase or delete modem stuff after unlocking bootloader. You don't kill someone's phone with unlocked bootloader....stay away from stuff you have no idea.

pranavateja99 said:
4g only sim1 signal Problem is bcz *#*#4636#*#* mode selected to United states....Lenovo stock has U.S option only. If someone select united states then sim1 is stuck to 4g mode.
*#*#4636#*#*
Lenovo Stock ROM has only mode option: United states.
Custom ROM has 2 modes: Automatic and united states as options. Selecting Automatic fix sim1 4g only issue.
Solution for different users:
---------- Post added at 12:31 PM ---------- Previous post was at 12:16 PM ----------
For bootloader locked you can do anything to fix. Flashing anything can fix it. Bcz fastboot flash can rework modem. Everything is a fix.
For bootloader unlocked devices fastboot don't flash modem files. Only way is to install custom ROM...Dail *#*4636#*#* and selecting Automatic and restarting the device fix sim1 4g only error.
*#*#4636#*#* U.S settings problem stays even user updates from S062 to S244 via OTA. Like IMEI stays this setting to stays.
Never hit erase after unlocking bootloader in future for any signal or modem reasons. This lenovo p2 can screw your Android experience
---------- Post added at 12:39 PM ---------- Previous post was at 12:31 PM ----------
Never suggest without knowing everything completely. You know and seen one side of a coin. P2 will show you real stars if you ever tried to erase or delete modem stuff after unlocking bootloader. You don't kill someone's phone with unlocked bootloader....stay away from stuff you have no idea.
Click to expand...
Click to collapse
Check the post I will already mentioned that bootloader unlocker devices are lost their imei, dont do any thing without a nandroid backup
And my first method is used to all the update the device and not cause any problem
Sent from my Lenovo P2a42 using Tapatalk

salmanvts said:
Check the post I will already mentioned that bootloader unlocker devices are lost their imei, dont do any thing without a nandroid backup
And my first method is used to all the update the device and not cause any problem
Click to expand...
Click to collapse
Even nandroid backup don't help restoring signal and ear piece sound errors....this is p2 and you can't flash fastboot modem image and you can't even relock bootloader. this is not normal like rest of the phones you used. Only QCN backup with QPST can backup IMEI+ rest and restore without issues. Only QPST Qfil flashable image bring back bootloader unlocked and messed up P2. This QPST image has to come from Lenovo, or someone has to make it with some internal sources and tools. So P2 is not normal stuff you used till now..it's locked Lenovo great sh*t....I don't know what they gain with bootloader warranty terms. But it's a hard messup ship for developers on XDA.

I bought a used P2 and I get no signal when inserting my SIM. I restored a nandroid backup from another P2 (Boot, Data and System). Could that be the reason it's not working? In that case, I wouldn't understand why it would have such an impact.

eried1 said:
Could that be the reason it's not working?
Click to expand...
Click to collapse
It is the main reason!

sergsinger said:
It is the main reason!
Click to expand...
Click to collapse
I had no idea that could happen when you only flashed boot.img, data and system (same OS version). Used to do it all the time when I owned a couple of LG G2s.

i did the erase modem and now have no signal at all now what do i do

pranavateja99 said:
Even nandroid backup don't help restoring signal and ear piece sound errors....this is p2 and you can't flash fastboot modem image and you can't even relock bootloader. this is not normal like rest of the phones you used. Only QCN backup with QPST can backup IMEI+ rest and restore without issues. Only QPST Qfil flashable image bring back bootloader unlocked and messed up P2. This QPST image has to come from Lenovo, or someone has to make it with some internal sources and tools. So P2 is not normal stuff you used till now..it's locked Lenovo great sh*t....I don't know what they gain with bootloader warranty terms. But it's a hard messup ship for developers on XDA.
Click to expand...
Click to collapse
Hi pranavateja99,
i have a p2 and i dont a have signal, no service at all on both sim.
I tried many variant of solutions, and unfortunately still wrong.
Ive tried stock rom 6.0 and ota update , nothing.
After few mounts i have no idea what can i do. i could fix my former phones but this one is beats me...
I just want to ask if you can give me some advice how can i fix it if is possible at all....
custom rom lineage, nothing, delete modem, nothing. bootloader is unlocked and this point when i found your comment here.
regards Steve

Get LTE Back

Hello guys,
As I have stated on my Q&A thread I was going to be posting a tutorial in order to bring LTE back for those who had lost it. I will give you some background in order for you to know how I lost it and then I will explain how did I get it back:
How did I lost it:
I had bought a Xiaomi Mi A1, and had given my previous Redmi Note 5 SD636 to my wife, for reasons that don't care at this time haha. So, I get it and I am on carrier Tigo Colombia, which uses band 4 AWS-1 . Everything was working as expected, I had my 4G LTE as a regular user. I had installed the gcam, unlocking bootloader and then relocking it, flawless. Everything was working perfect.
The issue came, when I decided that was time to try one of the AOSP Pie roms. I decided to try Simplix Blue, which called my attention due to not being available on RN5 the device that I used to own. I am pretty sure, that has nothing to do with the rom, for reasons that I will explain later on, but more fault of the SD625, boot.img and modem of the device. So I flashed the rom, as I usually do, following instructions, installing TWRP, changing slot, bla bla bla.. you already know this. So I booted up the rom, and it was on 3g, seemed strange, but on the initial set up I thought myself it was more of configuration on the network side. So, as soon as I finished the set up, I went into settings and selected LTE/WCDMA, did not work. Selected only LTE, did not work. Dialed #*#*4636*#*#, choose LTE network, did not work. So I said, this is more of a ROM problem then. Installed Arrow OS, same issue. Started getting strange, so I said, maybe it is a stock rom problem on my device, so I downloaded Stock ROM and flashed. Surprisingly, did not work either.
So I started to look around for solutions, wrote on telegram group and got ignored, as usually happens on that group, and I posted a Q&A thread here, which you can find here:
https://forum.xda-developers.com/mi-a1/help/lost-lte-pie-t3852725
Got no response at first, and then I saw some similar threads with same issue but no resolution. So I started looking for myself. Lasted 2 days looking for a solution as I was completely sure it was not a Hardware issue as I had it before. So, I will explain how I get it back after combining a tutorial with some personal knowledge.
I need to give credits to: @kirtikhurana, he does not even know I used his tutorial for Lenovo P2 haha, but it is worth it thanking him as his thread helped me a lot.
What we need:
QPST
QXDM (You can find this two programs on this thread, 3rd post https://forum.xda-developers.com/lenovo-p2/how-to/enabled-4g-ca-p2-t3707584) Once again, thanks to the creator of the thread for this.
Minimal ADB and Fastboot
LTE Band Calulator app(Which you can find on play store)
Network signal guru app (Which you can find on play store too)
Stock rom (Then you can change it and flash whatever rom you want)
First thing, is have the stock rom rooted, with magisk or whatever method you choose to root it. We will connect the phone to our PC and turn on the USB debugging. For the ADB and fastboot, let's make sure we open the CMD with administrator rights.
I will assume you had already installed QPST and QXDM. We will open a CMD where we have ADB and Fastboot and type:
Code:
adb shell
and then:
Code:
su
We will grant adb shell superuser rights on our phone. As soon as superuser rights are granted, we need to enter on DIAG mode, for that, we will type on the CMD:
Code:
setprop sys.usb.config rndis,diag,adb
On the original thread, it is stated that you can also dial *#*#717717#*#* to enter directly in diagnostic mode (Use this option if QPST does not detect your phone on following steps and reboot).
Now, we will go to QPST>bin folder and open QPST Config, with administrator rights. Check whether your phone is connected or not on diagnostic mode. I will clarify something here:
On the second tab of the QPST Config, you will see an option to add ports, by default, you can select COM1, which is usually not the port where we connect the USB. If that happens and does not detect your device, go to device administrator in the control panel, and make sure your android phone is detected as Diagnostic device, you can check that on USB and ports, where you will also find COM1 as another device. As soon as you make sure drivers and everything is ok, but still does not detect the phone, do the step previously mentioned of: *#*#717717#*#* and reboot.
Now, assuming that your phone is showing there, you will now go to QXDM>bin and open on the tools bar, options and click on communications: You will see your device and the type of model of the processor, in this case, should be MSM8986 or similar. Check below and you will see an option called target port, check on drop down list and choose the com port where you have your device. Now you can close that window.
Now, we will go to view and pick NV Browser, then look for the filter LTE. Then we will select the first option (if this and the other option if grayed out means it has not taken the connection of your phone).
On that first option, you will see two fields below. We will choose the first one and click on read. As soon as we do that, it will autopopulate a number, that number are the bands that you have enabled.
Let's go now to our phone and open LTE band calculator, and let's pick up the bands we need to have (if you write a random number on the app, it will show you which bands will be selected with that number).
Having that number, we will, in QXDM, double click on the input field and write the number that the app has given us and then click on write. As soon as we do that, we need to reboot the phone.
Now, when the phone is already rebooted, we will open network signal guru, provide corresponding permissions and now, click on the three dots at the top right corner and click on lock bands, select LTE. Now, you will see that the band that you were missing, for you to get LTE is there! So what you need to do is select it and click accept. Your phone will freeze for a bit and then reboot itself.
As soon as the phone is rebooted, you will see that you have your LTE back!!
This was the way I was able to get it.
I said it was not a rom, because if you flash stock rom again, with miFlash, you may loose LTE again and need to repeat the process as it happened to me. However, if you are on stock and decide to flash another rom, oreo or pie, you will not lose it.
Hopefully is clear enough for you guys who are facing this issue.
Regards

I lost also band 20 after flashing LOS and after that latest stock
So if i install LOS 15.1 after this method, band 20 will stay unlocked?
Thanks

trance89 said:
I lost also band 20 after flashing LOS and after that latest stock
So if i install LOS 15.1 after this method, band 20 will stay unlocked?
Thanks
Click to expand...
Click to collapse
Yes sir it will! You can do it with no issues whatsoever.

And if i root my system with patched boot.img + magisk method and after this mod i just revert back the untouched boot.img then can i relock bootloader?
ota updates or factory reset won't destroy it?
Thank you

trance89 said:
And if i root my system with patched boot.img + magisk method and after this mod i just revert back the untouched boot.img then can i relock bootloader?
ota updates or factory reset won't destroy it?
Thank you
Click to expand...
Click to collapse
You can do all your stuff. Only thing is if you flash again via MiFlash stock rom, then it may break and you may need to redo the process. But besides that, you can root, unroot, install custom, everything you want to do and you will not loose your band.

Please help! I can't seem to get the device into diagnostic mode or the damn windows drivers don't work. I've installed minimal ADB and drivers from xiaomi. as soon as I enter setprop sys.usb.config rndis,diag,adb no vibrate or anything on my device and in my windows device manager the Android device changes to an ADB interface and a Android device with a yellow exclamation mark. Dialing *#*#717717#*#* doesn't do a thing. I'm on LOS 15.1. Of course no com1 ports to connect to Any ideas?

saski4711 said:
Please help! I can't seem to get the device into diagnostic mode or the damn windows drivers don't work. I've installed minimal ADB and drivers from xiaomi. as soon as I enter setprop sys.usb.config rndis,diag,adb no vibrate or anything on my device and in my windows device manager the Android device changes to an ADB interface and a Android device with a yellow exclamation mark. Dialing *#*#717717#*#* doesn't do a thing. I'm on LOS 15.1. Of course no com1 ports to connect to Any ideas?
Click to expand...
Click to collapse
use google usb driver, it works with all devices: https://developer.android.com/studio/run/win-usb
Jemec26 thanks for the step by step instructions, i got back my lost band

saski4711 said:
Please help! I can't seem to get the device into diagnostic mode or the damn windows drivers don't work. I've installed minimal ADB and drivers from xiaomi. as soon as I enter setprop sys.usb.config rndis,diag,adb no vibrate or anything on my device and in my windows device manager the Android device changes to an ADB interface and a Android device with a yellow exclamation mark. Dialing *#*#717717#*#* doesn't do a thing. I'm on LOS 15.1. Of course no com1 ports to connect to Any ideas?
Click to expand...
Click to collapse
Go with stock rom first. It is not mandatory, but on other roms it may not work.

trance89 said:
use google usb driver, it works with all devices: https://developer.android.com/studio/run/win-usb
Jemec26 thanks for the step by step instructions, i got back my lost band
Click to expand...
Click to collapse
Glad it helped you!

saski4711 said:
Please help! I can't seem to get the device into diagnostic mode or the damn windows drivers don't work. I've installed minimal ADB and drivers from xiaomi. as soon as I enter setprop sys.usb.config rndis,diag,adb no vibrate or anything on my device and in my windows device manager the Android device changes to an ADB interface and a Android device with a yellow exclamation mark. Dialing *#*#717717#*#* doesn't do a thing. I'm on LOS 15.1. Of course no com1 ports to connect to Any ideas?
Click to expand...
Click to collapse
to make use of qualcomm diagnostic mode you must use qualcomm driver, take a look here https://forum.xda-developers.com/mi-a1/how-to/tool-low-level-backup-restore-unbrick-t3790307 in faqs section.
and here an explanation https://forum.hovatek.com/thread-22399.html

Main branch of los and aosp has network issue it needs to be fixed from scratch.

Ok finally I've managed to work through this and it now shows that band 20 is finally back enabled! However there is still no LTE band 20 reception (only band 3 in the city) and yes LTE band 20 signal strength is good when checking with other devices.
Anyway thanks so much for this tutorial but I guess my MiA1 is defective or bricked beyond repair. ;(

saski4711 said:
Ok finally I've managed to work through this and it now shows that band 20 is finally back enabled! However there is still no LTE band 20 reception (only band 3 in the city) and yes LTE band 20 signal strength is good when checking with other devices.
Anyway thanks so much for this tutorial but I guess my MiA1 is defective or bricked beyond repair. ;(
Click to expand...
Click to collapse
Weird. Please upload a pic when you can of the lock bands on the network signal guru app. Also, check with the *#*#4636#*#* the network mode that you are currently running. If your band 20 is already enabled, you should get it. Have you tried different sim?

Jemec26 said:
Weird. Please upload a pic when you can of the lock bands on the network signal guru app. Also, check with the *#*#4636#*#* the network mode that you are currently running. If your band 20 is already enabled, you should get it. Have you tried different sim?
Click to expand...
Click to collapse
Can't upload a screenshot since I'm at work now. LTE discovery shows only Band 3 LTE in the city and no LTE at all only 2G/3G in rural areas (where LTE Band 20 is availble!). Already switched SIMs they work fine (Telefonica Germany).
Signal Guru shows the following locked LTE bands:
B1:2100
B3:1800+
B5:850
B7:2600
B8:900 GSM
B20: 800DD (this one is new since I've unlocked it!)
B34: TDD 2000
B38: TDD 2600
B39: TDD 1900+
B40 TDD 2300
#*#*4636#*#* Shows Radio Band Automatic. Will Check all my steps again. could it be that I need to disable some bands in order to get band 20 working? Got my hand on a working MiA1 and it shows less LTE bands than the faulty one.

saski4711 said:
Can't upload a screenshot since I'm at work now. LTE discovery shows only Band 3 LTE in the city and no LTE at all only 2G/3G in rural areas (where LTE Band 20 is availble!). Already switched SIMs they work fine (Telefonica Germany).
Signal Guru shows the following locked LTE bands:
B1:2100
B3:1800+
B5:850
B7:2600
B8:900 GSM
B20: 800DD (this one is new since I've unlocked it!)
B34: TDD 2000
B38: TDD 2600
B39: TDD 1900+
B40 TDD 2300
#*#*4636#*#* Shows Radio Band Automatic. Will Check all my steps again. could it be that I need to disable some bands in order to get band 20 working? Got my hand on a working MiA1 and it shows less LTE bands than the faulty one.
Click to expand...
Click to collapse
Hmm I did not have to disable other bands but you can try and let us know, it won't damage anything and you can always make a backup. Try disabling bands that you know are not in use.

Tried everything disabled bands - nothing helped. Last Idea was to use the low level backup tool https://forum.xda-developers.com/mi-a1/how-to/tool-low-level-backup-restore-unbrick-t3790307 to backup all partitions from a functioning device with LOS installed and restore it to the one with LTE issues. Now the IMEI is gone. Reflashed August 2017 ROM with miflash to get the damn thing into diagnostic mode again (doesn't that work with LOS?) restored my IMEI, triggered OTA and got a boot loop. I'm afraid I've bricked my device beyond repair
update: I cannot mount my system_a partition in TWRP anymore. flashing stock fails with:
target reported max download size of 536870912 bytes
sending sparse 'system_a' (516697 KB)...
FAILED (data transfer failure (Too many links))
finished. total time: 4.295s
"Flash system_a error"
Any ideas? system_a cannot be 516697 KB in size no way!

saski4711 said:
Tried everything disabled bands - nothing helped. Last Idea was to use the low level backup tool https://forum.xda-developers.com/mi-a1/how-to/tool-low-level-backup-restore-unbrick-t3790307 to backup all partitions from a functioning device with LOS installed and restore it to the one with LTE issues. Now the IMEI is gone. Reflashed August 2017 ROM with miflash to get the damn thing into diagnostic mode again (doesn't that work with LOS?) restored my IMEI, triggered OTA and got a boot loop. I'm afraid I've bricked my device beyond repair
update: I cannot mount my system_a partition in TWRP anymore. flashing stock fails with:
target reported max download size of 536870912 bytes
sending sparse 'system_a' (516697 KB)...
FAILED (data transfer failure (Too many links))
finished. total time: 4.295s
"Flash system_a error"
Any ideas? system_a cannot be 516697 KB in size no way!
Click to expand...
Click to collapse
Whoa bro. I stated on the thread that you need to have stock rom. LOS may not work, after that you could install it. Now, for the prob that you have, try downloading a different image, try to even downgrade it to 7 and see if it works to restore partitions. I would suggest july firmware, some of the fw are not full, some do not even touch partitions, I know that july does, reason why I am suggesting it

Will this work for this problem? https://forum.xda-developers.com/mi-a1/help/4g-update-to-pie-t3877027 It's quite similar.... but with stock beta pie....

arc4d14n said:
Will this work for this problem? https://forum.xda-developers.com/mi-a1/help/4g-update-to-pie-t3877027 It's quite similar.... but with stock beta pie....
Click to expand...
Click to collapse
Yes, it will work. But i suggest you to wait the official fix.

jack_21 said:
Yes, it will work. But i suggest you to wait the official fix.
Click to expand...
Click to collapse
Thank you, I'll wait for a couple of patches before trying this, I just wanted to now all the alternatives