[Samsung Galaxy S7 Questions and Answers] eLily:
Galaxy S7 G930F stuck on "No Command" screen after trying to flash back stock

Hello All,

First of all thank you all for your posts. I'm reading XDA forums for years and use rooted phones with custom ROMs thanks to the info you are all posting here :D

I've recently received a brand new S7 SM-G930F.

First thing out of the box I wanted to get rid of Google and Samsung bloatware and flash LineageOS (like I've done with previous phones), but ended up as a hopeless lady stuck in a boot loop :eek:

This is what happened:

Flashed a brand new S7 SM-G930F (Android 8.0 installed) with TWRP (3.2.3), LineageOS (14.1-20181011-nightly), Magisk (17.1), Xposed.

I then restored a TWRP backup from a S7 SM-G930FD (same LineageOS, but from a dual sim version phone).

Initially everything worked fine, then I noticed the SIM card is not recognised and that the baseband version is "unknown".

Also, every time I connected to my Wifi network while the other S7 SM-G930FD was connected as well, the last was disconnected.

Diving into XDA forums! :cool: Reading and reading, I figured the only way to fix it is to run a TWRP backup, wipe everything and flash a stock firmware on my device. Then flash TWRP again and either restore LineageOS backup or starting from scratch (without wiping system to keep the baseband version).

Things went down south when I tried to flash stock with Odin 3.12.3 (never did I ran into trouble doing this before!).

Flashing did not pass.

Downloading a different stock image from SamMobile and flashing, this time it did pass, but had another problem:

After flash the phone showed an "Installing software update" on a blue screen for about 30 seconds.

Then the message has changed to "Erasing" for about 5 seconds more.

Eventually received a blue "No Command" screen with a yellow warning symbol.

Tried to reboot. Then clear cache and reboot. Then wipe data. Tried to flash another stock image from SamMobile (different carrier), again getting to "No command" screen.

Did that with several stock images from different carriers, both with Android 8.0 and 7.0. All resulted with a "No command" screen.

I then flashed TWRP once again through Odin.

Wiped the phone and install LineageOS. Works! :victory:

LineageOS boots fine, just not recognising the SIM (as before). Also when I go to Settings → SIM cards, I have SIM 1 and SIM 2. Both are not recognised, but this is not a dual SIM phone :confused:

Relaxing that the phone can still function, I tried once more to flash stock through Odin.

Flashing did pass, phone rebooted, got an "Installing software update", message which changed to "Erasing", then I've received an "Error" screen. Looks exactly as the "No command" screen.

Now whenever I'm rebooting the phone it is stuck on boot screen. Although I can still get into recovery or install TWRP via Odin.

This is Odin's message when flashing stock fails:

[IMG="Odin's message when flashing stock fails"]https://pictshare.net/mk29qkh9c6.jpg[/IMG]

Here is a photo of the message I see when booting into recovery.

[IMG="Message when booting into recovery"]https://pictshare.net/zlotok1j9k.jpg[/IMG]

Text of this message here:

Installing system update
Error!

#fail to open recovery_cause(No such file or directory)#

#Reboot Recovery Cause is [UNKNOWN]#

File-Based OTA
Supported API: 3
E:[libfs_mgr]Blob verification failed :255
E:Failed setting up dirty target
dm-verity verification failed...
E:[libfs_mgr]Error creating device mapping: Device or resource busy
E:[libfs_mgr]Couldn't create verity device!
E:Failed setting up dirty target
[omc-app-link] fail to mount /system as rwE:[libfs_mgr]Error creating device map
ping: Device or resource busy
E:[libfs_mgr]Couldn't create verity device!
E:Failed setting up dirty target
[omc-permission] fail to mount /system as rwE:[libfs_mgr]Error creating device m
apping: Device or resource busy
E:[libfs_mgr]Couldn't create verity device!
E:Failed setting up dirty target
[omc-sysconfig-permmission] fail to mount /system as rwE:[libfs_mgr]Error creatin
g device mapping: Device or resource busy
E:[libfs_mgr]Couldn't create verity device!
E:Failed setting up dirty target
[omc-permmission-permmission] fail to mount /system as rwE:[libfs_mgr]Error creat
ing device mapping: Device or resource busy
E:[libfs_mgr]Couldn't create verity device!
E:Failed setting up dirty target
[omc-res-permmission] fail to mount /system as rwE:[libfs_mgr]Error creating devi
ce mapping: Device or resource busy
E:[libfs_mgr]Couldn't create verity device!
E:Failed setting up dirty target
[hwr_symlink] fail to mount /system as rw

When I click Mount /system and reboot nothing changes.

Device technical info:

Device out of the box:

Android version: 8.0.0

Baseband version: G9730FXXU2ERD6

Kernal version: 3.18.14-13438344-QB18292513; dpi@SWDG9815#1, Sat May 26 15:53:42 KST 2018

Build number: R16NW.G930FXXU2EREM

Knox version: Knox 3.1, Know API level 25, TIMA 3.3.0

Device after flashing TWRP/Magisk/Lineage:

Android version: 7.1.2

LeneageOS version: 14.1-20181011-NIGHTLY-herolte

LineageOS API level: Guava (7)

Device after flashing stock firmware again:

samsung/heroltexx/herolte

8.0.0/R16NW/G930FXXS3ERI1

Hope there is a genius here that understand how I can fix this. I was assuming that going successfully back to stock will sort the baseband version/kernel and the phone will read the SIM card again, but I may be wrong?

Please share your insights!

Thank you :angel: