Same problem with my BQ M8...
Here is how I solved it:
-With the phone conected via USB, Launch CMD to run ADB and test as many times as needed that the PC and terminal can talk to each other with the command "adb devices". Eventually after several attempts, it will return the device and number. Posibly stating the work "recovery".
-Go into bootloader ...
This can be marked a duplicate of questions like this, but it's a device-specific question. It cannot be answered in a generic way, it should be “How to root XYZ Android device without unlocking bootloader?”
Simple answer is: It should not be possible to root Android devices without unlocking bootloader, but it's possible for some devices due to security ...
My reply is built on my assumption that the OP want to ask about his device's root status, and if it's been altered or not
Check Selinux Status:
Selinux defines which process can access a given resource on your device. AFAIK, all Android device manufacturers companies ship their devices with Selinux Enforcing (Default), in some custom ROMs you may find ...
Do you really want to flash a custom firmware in your phone or just back your phone again?
I need some answers about your phone..
1. Is your phone was rooted and then you tried custom recovery ? or its bricked before rooting? If your phone is rooted then you can try to flash a custom rom for you phone . If its nor hard bricked then your phone will be okey ...
Remember that the custom ROM package will include the boot image too. And on A/B partition devices, the recovery rests is in the boot image. So, if the custom ROM has written your boot image, then your TWRP should be gone. What will load will depend on the recovery included in the boot image. It could be stock, something else or nothing.
This seems to happen if you download the wrong twrp - I had downloaded the S5 twrp. The only other thing to note is when in the stuck Downloading... screen, you can hold Power + Volume Down button to turn off the device.
Fastboot is implemented in bootloader (like aboot or LK) i.e. in boot chain it loads even before the first process (kernel) of main OS. It has its own very minimal kernel which doesn't recognize any hardware components (even on device) except those necessarily required at this stage (processor, memory, display, flash storage etc.). Communication with PC over ...
You can use the following command from an adb prompt to enter into your devices recovery mode without using a physical button during restart.
1) Start adb prompt on your PC / MAC / Linux
2) Make sure adb is running adb start-server
2) Make sure the device is present when you run: adb devices
3) Now run adb reboot bootloader and your device will restart ...
This was solved using clues from this post
If you only need to authorize one computer:
Simply copy the adbkey.pub
onto the device location:
/data/misc/adb/ and rename it from
adbkey.pub to adb_keys
chmod 0644 and then reboot.
I forgot to do the chmod but still works.