yashsingh1/xdaforums huggingface dataset:
[Lenovo P2 Questions & Answers] mishua0:
very sad ! didn't you make a full backup (nandroid backup) through TWRP ?? If so, then you should install twrp img again and restore the back up. please let me know. otherwise I'll give you my TWRP backed up modem file.
[Lenovo P2 Questions & Answers] Vis77:
My story:

I was originally on Nougat, unlock bootloader, install TWRP, erase SYSTEM/internal/cache, installed deodexed nougat -> no sim detected

Restored my full Nougat backup -> no change

Fastboot flash Nougat -> no change

Restored trough TWRP [MENTION=5656324]nandakis4[/MENTION] full Nougat backup https://xdaforums.com/showpost.php?p=71909467&postcount=340 -> sim working, internet workig, but i don't hear anything douring calls

I tried almost all custom rom -> internet and calls working, but the CPU behaved strangely

Installed STOCK Nougat in TWRP -> no simcard

At last i was on the latest RR 5.8.3, then i accidentally dirty flashed the STOCK deodexed MM -> everythings working fine with the deodexed MM rom

I hope it will help.
[Lenovo P2 Questions & Answers] harsh_xda:
Found a fix!

Thank you guys [MENTION=6935070]mishua0[/MENTION] and [MENTION=7196522]viss77in[/MENTION] for your kind concern but I found a fix later on the web. Actually I learnt that after erasing the modemst files it is recreated by the bootloader but due to some problem it was not able to recreate that. So I re-flashed the boot.img and deleted the modemst files once again. These were the commands that helped me(on Mac):

./fastboot flash boot boot.img

./fastboot erase modemst1

./fastboot erase modemst2

./fastboot flash fsg fsg.mbn

./fastboot reboot

I rechecked the commands it worked for the 2nd time too. So I came to the conclusion for the fix of 'No Sim Card Inserted' issue. :)
[Lenovo P2 Questions & Answers] mishua0:
you are lucky that this trick worked for you but this didn't work for some users, they told that after a few second their radio signal disappeared continuously. Even they had to go to service center for repairing. I want to know if you still facing some of this kind of problem or not ....... hope yours is now in best condition ! thanks ......
[Lenovo P2 Questions & Answers] Vis77:
I try debug my working version (i made full backup first), step by step flashed the following:

fastboot flash boot boot.img no "no sim card error", but i hear nothing during calls

fastboot erase modemst1 and

fastboot erase modemst2 nothing changed

fastboot flash fsg fsg.mbn "no simcard error"

After i restored my TWRP backup I thought everything would be fine, but i realize no sound comes from the phone when making a call (again :eek:)

Conclusion 1: Do not poke what works :rolleyes:

Conclusion 2: The TWRP don't save/restore all (partition?) data
[Lenovo P2 Questions & Answers] PrasadD:
I'm trying this as Im facing same issue (no voice during calls - no ear speaker or loud speaker)
[Lenovo P2 Questions & Answers] PrasadD:
Hi, can you help me how to restore twrp backup (the link has a file like backup s233-2017-04-18--00-08-10.rar). When I try to restore from twrp it is not even showing this file.
[Lenovo P2 Questions & Answers] PrasadD:
You really saved my day with TWRP backup.... if we screw up modem (bootloader unlocked) this is the only method that works.
[Lenovo P2 Questions & Answers] eried1:
Has anyone had any success flashing stock Nougat? I suppose [MENTION=8193074]harsh_xda[/MENTION] and [MENTION=8089910]Vis77[/MENTION] flashed MM. Would be interesting to hear if it worked out flashing just system.img, thus leaving out bootloader (which contains modem). Since it's the same OS version, I think there's a chance.

Also, did anyone try restoring just the modem via TWRP? Please mention if it was erased or just restored (hence excluded from the flashing process).

Clearly, you should never erase the modem with an unlocked bootloader.
[Lenovo P2 Questions & Answers] sisqin1:
Did it work for you?

Can you please advise the steps followed.

I have a bricked device and unable to make or receive calls.

Thanks
[Lenovo P2 Questions & Answers] PrasadD:
1. Downloaded the twrp backup files (some one shared the link as shown below):

".....Restored trough TWRP [MENTION=5656324]nandakis4[/MENTION] full Nougat backup (https://xdaforums.com/showpost.php?p=71909467&postcount=340)"

2. Restore this using TWRP. (After this calls will be blank even though it connects to network)

Note that you need to copy this backup folder to specific path like /TWRP/BACKUPS/ZY223VLMS9

Otherwise TWRP will not detect this backup.

3. Now download stock marshmallow firmware (that comes with fastboot, name is something like this: P2a42_S048_161111_ROW_fastboot.zip).

(you should easily find this on internet).

4. Extract the zip and copy the attached file (Yukle.exe) in to the folder. ( https://drive.google.com/drive/folders/0BxNr7DAO-62AQ1lzaXlWdmhxR1E?usp=sharing )

5. Run Yukle.exe from command line.

6. After this step SIM problem will be still there. At this point follow OTA updates (first 100 MB one) and then (1900 MB one).

Note that this a long process...it should take around 2-3 hours, so be patient and get your phone working.

7. After completing you will have working phone including calls.
[Lenovo P2 Questions & Answers] sisqin1:
Thank you i will try this and report back.. Was you boot loader unlocked or locked?
[Lenovo P2 Questions & Answers] PrasadD:
If bootloader is locked then we will not have these problems. (that means fastboot will flash full firmware without any issues. ).

My bootloader is unlocked, thats the reason for these issues.
[Lenovo P2 Questions & Answers] sisqin1:
I completed the process.. I see the name of the Network providers .. followed by No Service.

I try to make a call it says network not available.

Any advise?
[Lenovo P2 Questions & Answers] PrasadD:
Are you on Android.6 or Android.7 ?

If you are on Android.6 check the OTA and upgrade till you get Android.7

If you are already on Android.7 then try restoring the full TWRP backup again as mentioned in first step. After restart it should work.

By the way it is for P2a42, for other versions this process may not work.
[Lenovo P2 Questions & Answers] sisqin1:
Here is what i did .

I was on 7.0.

1) Restored the backup from TWRP.

2) downloaded the firmware file and used Yukle.exe. Downgraded to 6.0, still had the SIM issue.

3) Received OTA update around 109mb.. Updated

3) Received OTA update around 1900mb... Updated.

4) Restarted the phone. It shows the operators name but says no Service. Unable to make or receive a call.

any steps i am missing.

Yes i am using the Indian version that is P2a42

Thanks
[Lenovo P2 Questions & Answers] PrasadD:
All the steps are right. Not sure what you are missing.

I will zip and share TWRP backup of MM firmware, try restoring and check.

Give me some time.
[Lenovo P2 Questions & Answers] PrasadD:
Here is the link for Marshmallow TWRP backup:

https://drive.google.com/open?id=0B2FdRtvxaZwPWV9oeERFZmJub2M

Try the above, if not I will try to share Nougat backup tomorrow.
[Lenovo P2 Questions & Answers] sisqin1:
Thank you for uploading such a huge file.

I tried restoring from TWRP and when downgrading its getting stuck in bootloop and the baseband became unknown.

Can you please ipload the Noguat recovery i can try using that.

Thanks
[Lenovo P2 Questions & Answers] eried1:
I'm grateful as well. Does this file have an unlocked bootloader and working modem? I suppose the downgrade could fail anyway, but would be nice to know.
[Lenovo P2 Questions & Answers] PrasadD:
I dont think bootloader will be flashed, anyways I have unlocked bootloader.

I have working modem.
[Lenovo P2 Questions & Answers] eried1:
You're right. I just thought you could run into compatibility problems if the system thinks you're locked but you're really not.
[Lenovo P2 Questions & Answers] PrasadD:
This is even bigger file.

https://drive.google.com/open?id=0B-WKS4S9DStaY29Zd3A0dV9TOVE

---------- Post added at 04:59 AM ---------- Previous post was at 04:55 AM ----------

Not sure why it goes into bootloop. Make sure you wipe all cache, system and data partitions before restoring.
[Lenovo P2 Questions & Answers] sisqin1:
Thank you Prasad!!!

It worked, i was finally able to send and receive calls.

Here is what i did.

1) Restored the TWRP backup. No signal.

2) Downgraded to MM using Yukle.exe.. Still no signal.

3) Received 100mb update.. updated.. Still no signal.

4) Received 1900mb update.. updated..Inserted the sim card and was able to get signal and able to make and receive calls.

Hope this helps anyone facing the issue.
[Lenovo P2 Questions & Answers] PrasadD:
I tried multiple ROMs but it seems Stock Nougat is better overall. Screen ON time and stand by Battery are good.

Rooted and installed Greenify- Enable Doze and Wakelock cutoff. Should be good enough.

Once Xposed is released for Nougat we can enjoy Amplify which I think will be better than any wakelock blocker.

If anyone has better setup for better battery then please post here... Thank you.
[Lenovo P2 Questions & Answers] PupPupG:
This fixed the issue for me as well :)!

Just an FYI when you restore with that backup you will be able to have access to your google account as it is already signed in

I would do a password reset on your account ASAP :)!
[Lenovo P2 Questions & Answers] PrasadD:
Ok... anyways its a dummy account :)

Thanks for reminding though.
[Lenovo P2 Questions & Answers] abhayruparel:
So does this means that flashall.bat screws up?
[Lenovo P2 Questions & Answers] rs260995:
hey i followed your procedure and when i flashed mm stock rom after installing your backup the google login screen at start says owner info required (its asking for your email and password ) which i m not able to provide and thats why i can't complete the whole procedure

please help
[Lenovo P2 Questions & Answers] PrasadD:
You can wipe data/cache from TWRP. It should clear all those issues.
[Lenovo P2 Questions & Answers] rs260995:
thank you PrasadD

you helped me get my sim card signal back, now i can make calls without any issue

your tutorial really works

thanks...:good::good::good::good::good:
[Lenovo P2 Questions & Answers] abhayruparel:
If any one here succeeded please open a new thread describing the process in guides section.
[Lenovo P2 Questions & Answers] pranavateja99:
Does anyone know why no signal error happens. I too face this....Restored to my twrp stock 7.0, morning will run downgrade and 109mb, 1933mb....will see what happens after all, Anyone please tell me what not to do to avoid this mess again....Before I flashed deodoxed 7.0,ext4., Tried 3 different custom roms, restored modem, efs....did all crazy combinations and finally no signal....so I need someone with knowledge to tell what is the reason mess with signal radio. And what not to do's
[Lenovo P2 Questions & Answers] rs260995:
to avoid this issue donot use flashall bat file provided with fastboot roms instead flash each file separately (including system, boot, recovery) then clear data and cache (for bootloader unlocked devices only)

bootloader locked devices can easily flash rom using the flashall bat file without any issue

i don't know what exact reason causes the no signal error but deleting the modem file has something to do with it and as we delete the modem files we cannot flash is back (in case of unlocked bootloader) thus causing no signal..

use this to flash stock firmware - https://www.youtube.com/watch?v=-b7bx7Dl17w
[Lenovo P2 Questions & Answers] pranavateja99:
Crazy Lenovo phones....not at all developer friendly. :angel:
[Lenovo P2 Questions & Answers] pranavateja99:
After all steps all everything...now I face a strange issue...sim1 works only in 4g mode, if I keep jio in sim1 and Airtel in sim2, I get both signals. If I keep Airtel in sim1, no signal and if I scan it shows only 4g networks and if I try scanning in Gsm only mode then I get "error while for networks"

---------- Post added at 02:36 PM ---------- Previous post was at 02:34 PM ----------

After all steps of prasad's, did everything...now I face a strange issue...sim1 works only in 4g mode, if I keep jio in sim1 and Airtel in sim2, I get both signals. If I keep Airtel in sim1, no signal and if I scan it shows only 4g networks and if I try scanning in Gsm only mode then I get "error while for networks"

Now I try yours individual flashing than fla****all....hope this will fix...any suggestions for sim1 being in 4g only mode.
[Lenovo P2 Questions & Answers] Lither:
Sorry to be off topic but how did you get Greenify to work in Nougat as I thought you need XPosed?
[Lenovo P2 Questions & Answers] PrasadD:
First:

We dont need Xposed for Greenify. Root is good enough.

At the time of writing that message I didn't had Xposed.

----

Second:

There is Unofficial Xposed for Nougat available now. I'm using Amplify with that and seems to be working fine.
[Lenovo P2 Questions & Answers] Roshan0746:
Guyz i jst flash MM stock firmware I can't here voice call that's why i search on YouTube there say

Fastboot erase modmst1

Fastboot erase modmst2

I follow this command and now both sim gone

No simcard shown

Anyway to restore modmst file?

Help me guyz

???
[Lenovo P2 Questions & Answers] Roshan0746:
Which twrp backup u flash?

I have same issue
[Lenovo P2 Questions & Answers] sisqin1:
drive.google.com/open?id=0B2FdRtvxaZwPWV9oeERFZmJub2M
[Lenovo P2 Questions & Answers] Roshan0746:
Bro I wrongly delete

Fastboot erase modmst1

Fastboot erase modmst2

This method will work to get back sim network?

Past 2 day all day I tried many instructions but doesn't work

Help needed???
[Lenovo P2 Questions & Answers] sisqin1:
yes it works, i had the same issue
[Lenovo P2 Questions & Answers] Roshan0746:
Yes it works, i had the same issue[/QUOTE

Now I'm on s048 stock firmware

Frst flash twrp backup

Then follow all step by step right?
[Lenovo P2 Questions & Answers] sisqin1:
yes, flash the twrp backup.

from twrp wipe data and system

downgrade to MM

update via updater

it will work
[Lenovo P2 Questions & Answers] ROSHAN0747:
i just try to restore twrp mm aicp backup

but it dosent restore stuck on only 2%

im on mm s048

wipe data nd system but it stuck on 2%
[Lenovo P2 Questions & Answers] cyrrrinda:
I had same issue and make it work using backup from another working P2. See post #70 and later from here:

https://xdaforums.com/lenovo-p2/help/stock-rom-t3552973/page7
[Lenovo P2 Questions & Answers] Mrinmay Medhi:
Hey there guys using P2 with unlocked bootloader please do this first in order to avoid loss of IMEI or anything else in future due to heavy flashings.

You can connect your phone to pc, install qfil or qpst, on phone dial ####8899# click ok to enter diag mode, in qfil it will read a com port, click tools then QCN backup restore.. click backup..

You will find a file in C:\temp:\00000.qcn

Keep it safe..

If you lose imei and network cuz of bad flashing repeat the process but restore and reboot..

If not on stock rom you'll need root and adb or terminal instead of dial code

su

setprop sys.usb.config diag,adb

Credit to [MENTION=7051441]adhammagdy[/MENTION]00 for instructions.

(if phone doesnt go into diag mode this wont work and it is recommended to do this on stock rom rather than custom roms)
[Lenovo P2 Questions & Answers] erlenkoenig:
For a solution have a look also at this thread:

https://xdaforums.com/lenovo-p2/help/stock-rom-t3552973/page8
[Lenovo P2 Questions & Answers] Shresth (IN):
Title says it all but i am posting the modemst1/2 files from that folder . If someone has any issues with the modem , copy these files to that folder from a root browser and set the permissions to 0660 . TWRP doesnt show bootdevice as a folder , so you have to copy these files once you are in a rooted system. Just unzip this folder and copy the files. I used ROM toolbox lite to find and provide these files .

EDIT : Please post an affirmative message if that works.

EDIT: Stop flashing stock ROMs from fastboot . Use the ROM zip from this thread and after clean wipe and /data as f2fs and while keeping system in read only flash this and upon boot you will have complete STOCK ROM

The thread is https://xdaforums.com/lenovo-p2/development/7-0-lenovo-p2a42-stock-nougat-update-t3581517
[Lenovo P2 Questions & Answers] eried1:
Anybody who can confirm that the method described by [MENTION=8365957]Shresth (IN)[/MENTION] works?

I haven't deleted my modem and my SIM card is detected, however, I do not get a signal. I'm quite convinced my IMEI is wrong.
[Lenovo P2 Questions & Answers] Shresth (IN):
Well , I don't think anyone has tried this since it was posted a while after the solution was out but since this places the required files in the required places , why don't give it a go
[Lenovo P2 Questions & Answers] :
don't flash all fastboot files on Unlocked bootloader nor erase or overwrite any modem of any file other than System chuncks.. , boot & recovery on unlocked bootloader in P2.

.

If however you messed up with P2

Try to flash the very first S4x MM Stock files only system chunks, boot & recovery, then do all 5-6 OTA updates till now.

Hopefully you'll get you voice issue or sim problem solved.
[Lenovo P2 Questions & Answers] eried1:
I know you are quite knowledgeable member of this forum. Had any success in bringing the signal back to life?

After restoring an older TWRP backup as well as QCN the phone can detect 4G networks, but 2G and 3G seem to be gone. I had flight mode enabled for a very long time before I was getting problems connecting to a network. I'm wondering if it might have been something wrong with my device from the very beginning; simply a faulty copy. As I wrote in an earlier post, I've never erased the modem or tampered with EFS and the TWRP is the original backup of the phone I'm using.
[Lenovo P2 Questions & Answers] eried1:
I'm on stock and it wasn't working for me. I think I entered debug mode. I had to use

setprop sys.usb.config rndis,diag,adb
[Lenovo P2 Questions & Answers] eried1:
I will since I've tried just about anything else. Which folder are you talking about? Where should modemst 1/2 be stored?

Edit: When I enter dev/block/bootdevice the files I see are mmcblk0, mmcblkp1-56 and mmcblk0rpmb. The subfolders are by-name and by-number. Btw, I noticed the bootdevice folder is showing 0 bytes so I checked it on my other P2 on which the signal is working. Apparently the way it should be.

I deleted modemst1/2 via fastboot and discovered that they seem to be recreated at reboot.
[Lenovo P2 Questions & Answers] Shresth (IN):
Clarification

They will show 0 bytes in the by-name folder BUT when you copy them to your sdcard and check its permissions it will show its true size and also the permissions it has check the size and compare them to the files inside the zip I uploaded
[Lenovo P2 Questions & Answers] eried1:
[MENTION=8365957]Shresth (IN)[/MENTION], so I tried this method of yours. It will restore the IMEI, however, I didn't get a signal.
[Lenovo P2 Questions & Answers] :
If you've messed up that far, why don't you try to lock your bootloader (there is a method in fastboot erase secinfo) first then flashall.bat in fastboot?

---------- Post added at 01:35 PM ---------- Previous post was at 01:32 PM ----------

Do some OTA you might get your signals this may not help but do try to lock your bootloader. Wish you could get success in that.
[Lenovo P2 Questions & Answers] Shresth (IN):
When u did this were u on s251 or s244 bcoz on s244 this was able to give me back my ability to make calls
[Lenovo P2 Questions & Answers] eried1:
The bootloader cannot be returned to the state it used to be when it was unlocked. If Lenovo allowed for this none of us would have any trouble.

2G and 3G will be lost forever once you've touched the modem and/or EFS. There's no way to restore it. 4G might be possible to restore. I think I've done it once (although I was losing the signal continously) and others have done it as well.

I bought an old P2 from Ebay (as a backup option to the one I already have) and never messed up so I think there's only one possibility. The motherboard was changed (the IMEI on the SIM tray doesn't match the one displayed in the phone)
[Lenovo P2 Questions & Answers] dkgagan7:
same issue , please give me a fix. ...or twrp backup :(

i wont buy lenovo phones from now
[Lenovo P2 Questions & Answers] dkgagan7:
can u please provide efs backup of twrp ........my modem partition got deleted .......no sims now
[Lenovo P2 Questions & Answers] gamefreaksuraj:
hey dude im getting same problem did u get any solution??? if yes then plz tell
[Lenovo P2 Questions & Answers] kishorrohsik:
i think link is down :crying:
[Lenovo P2 Questions & Answers] PrasadD:
Please try this...

https://drive.google.com/drive/folders/1Sg_Keq6oXz2BoG7HCjJ156t4O7DwNmbC?usp=sharing
[Lenovo P2 Questions & Answers] binaryhelix:
I am grateful to have discovered this critically important thread, issue has never happened to me but I want to be prepared in case it does

Currently running LOS 14.1 and want to change ROM

How do I backup my existing modem settings in case I accidentally remove them?

Thanks!
[Lenovo P2 Questions & Answers] GPSSlovakia:
I have SIM card detected, but no signal :(

downgrading to MM and then all OTAs did not help :(
[Lenovo P2 Questions & Answers] PrasadD:
I think you already have access. its in public shared folder.
[Lenovo P2 Questions & Answers] smyuksel:
I just could not download yukle.exe fromthe link above. Google drive needs an access grant. I approved the access request but dont know who will approve it. Please help...
[Lenovo P2 Questions & Answers] PrasadD:
Tried this link? I have shared it properly...not sure why its not working.

https://drive.google.com/drive/folders/1Sg_Keq6oXz2BoG7HCjJ156t4O7DwNmbC?usp=sharing

---------- Post added 25th November 2019 at 12:05 AM ---------- Previous post was 24th November 2019 at 11:59 PM ----------

Try again now...

https://drive.google.com/open?id=1Sg_Keq6oXz2BoG7HCjJ156t4O7DwNmbC

---------- Post added at 12:06 AM ---------- Previous post was at 12:05 AM ----------

https://drive.google.com/open?id=1Sg_Keq6oXz2BoG7HCjJ156t4O7DwNmbC
[Lenovo P2 Questions & Answers] rkpg:
Hi can anyone give me the link of the twrp backup file or give a new link, getting 404 error in the link provided by [MENTION=5656324]nandakis4[/MENTION]
[Lenovo P2 Questions & Answers] eried1:
Did you ever solve it?
[Lenovo P2 Questions & Answers] sunando:
I am in 2021 with a lenovo P2 as a secondary device . No baseband , no imie and no sim reception. Can I get it back ?
[Lenovo P2 Questions & Answers] hk73:
Can you reupload "YUKLE.zip" because google gives this message "

Sorry, this file is infected with a virus

Only the owner is allowed to download infected files."

If possible upload files on yandex it gives ability to download even just particular required parts from whole big zip file
[Moto Z Play Questions & Answers] joseph_s1lva2:
I intend to buy the chinese variant XT1635-03 at Gearbest. Is it possible to flash the XT1635-02 rom on it or will I be stuck with the chinese rom? If that is possible, would I receive the OTA updates?
[Moto Z Play Questions & Answers] RED LONDON:
You can flash the every rom you like i have the Chinese version and i flashed the Russian rom on it you just need to unlock your bootloader
[Moto Z Play Questions & Answers] joseph_s1lva2:
Thank you very much. Your answer was decisive for my decision on buying the device, and I think the chinese version comes already with the bootloader unlocked.
[Moto Z Play Questions & Answers] RED LONDON:
Mine had weird bootloader it was locked​ but I wasn't able to unlock it with the code that moto gave me if you had the same problem pm me ill tell you how to unlock it
[Moto Z Play Questions & Answers] joseph_s1lva2:
Thank you.
[Moto Z Play Questions & Answers] mahdif62:
You won't receive OTAs.
[Moto Z Play Questions & Answers] joseph_s1lva2:
It's not a big deal, as long as I can flash the latest roms.
[Moto Z Play Questions & Answers] joseph_s1lva2:
Sorry to bother again, but did you flash the entire rom? I read at other thread that it is dangerous to flash modem, fsg and bootloader from another variant.