[Samsung Galaxy J3 (2016) Questions & Answers] Alerion13:
Hello all,

After 5 hours searching and almost done, it seems like the phone won against me...

I have a friend who has his device under Android5, latest version, and need at least Android 6 to update his bank app, which required this update to work normally.

The worst part here, is that the device has the down volume button not working anymore (at all)

I wa a little rusty because I moved two years ago to iOS, but I have some memories with my old samsung and Nexus 6 flashing.

So here's what I've tried so far, I can forgot to mention some stuff because it's been a long work lol

So I have a 1GB SD Card and my indows 10 computer.

- I started to download and install all ADB and fastboot drivers.

- I've activated Debugged mod and OEM Unlock. I couldn't find if the bootloader is allowed for unlock or not, because the command didn't work. So I supposed that yes, it is. The device is the J3 SM-J320FN bought in France, new.

ADB work perfectly, but I didnt manage to get the device recognsied with the Fastboot mode. "ADB Devices" list the phone, but fastboot devices command does not show anything, it goes back to another line.

My friend didn't mentionned that he has installed a recovery. I don't know how, but the recovery is very basic. Here's a photo of the recovery screen. It appear when i press Vol+, home and power button, but I can't move anywehre because of the low volume button not working. Vol-, home and power doesn't work for the Download mode.

I finally managed to enter in download mode by using the command ADB REBOOT DOWNLOAD. With that, I honestly don't remember how I did it, but I think I've flashed a file which allow me to root the device from ODIN. With this, I've got confirmation of Root Checker app that the device is now rooted.

I've passed many hours to make some tests here and there, but nothing gave me a real result. Then I found two apps : ROM Manager and Flashfire.

ROM Manager : The app says that it doesn't find Superuser in System/bin/su. So it's like the device is not rooted. Nothing seems to work on the app too.

Flashfire : It seems like this app can do the job, but I can't finalize the process. So I've changed the year of the phone to 2013 to get the app running, I've tried a wipe, and here... Yahoooo ! A big Loading screen with many line codes, and then... nothing. My computer make the sound to say that it recognised the device, and a full blackscreen for 10mn. Exactly same process if I try to flash a ROM, or whatever action (even doing a backup).

I suppose it's because the app wasnt granted the root permissions. Not sure, because even if the phone seems to have the root status, I never get any pop up to ask if I allow to get the permission or not. I've tried to dwnload the APK for SuperSU app or something, and nothing seems to work.

So now, It looks like i'm close, but I also think that there is nothing more to do.

The device is powering on, with all its data, and seems rooted, but I can't do anything. It seems like the recovery is the only option to go trough the install.

So you guys, do you have any ideas of what can I do ?

I'd like to install LineageOS, but any ROM with Android 6.0 min. will be fine for me.

Also, pardon my english. I'm french lol

Thank you for your help..!