[Solved]fastboot oem lock -> bricked phone (black screen with notification led on)

telebog

New Member
Apr 11, 2017
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#1
I unlocked the boot loader and I tried several custom ROMs. Than I wanted to go back to original ROM and to have OTA. I tried a few time with no success and than I run fastboot oem lock. After this when I tried to power on it vibrates, shows the zuk logo for ~1sec and the display remains black with notification led on.

I tried to power off and then to hold Volume Up and Down while connecting to PC but I have no fastboot or adb. It is recognized as Qualcomm HS-USB Diagnostic 900E.

In order to have fastboot it needs to be recognized as QDLoader 9008?
Is there a way to unbrick my phone without using the modified cable solution?


Solved
- I fully charged the phone (the most important)
- When unplugged the cable the phone was black screen with notification led turn on
- pressed (and not release) power button: after ~10 sec the phone restarted (notification led turned off, zuk logo displayed ~ 1 sec), after about 4-5 sec notification led turned on, in a few seconds it turns off again, wait anoter 2-3 seconds and release the power button
- waited a few minutes (not sure if it is was necessary)
- pressed vol + and - and connected to PC USB. In few seconds I saw the fastboot menu on the phone
- released the vol + and -. It was not discovered by the PC.
- Opened cmd and run:
Code:
fastboot -i 0x2b4c flash unlock unlock_bootloader.img
fastboot -i 0x2b4c oem unlock-go.
I tried this 30-40 times without he phone fully charged. When it was not fully charged and it was black screen with notification led turn on when I pressed the power button : after ~10 sec the phone restarted (notification led turned off, zuk logo displayed ~ 1 sec), after ~10 sec the phone restarted. Even if notification led was off when I connected the phone to the PC with vol + and - pressed It didn't go to fastboot mode.
 
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