How to Unlock Bootloader and Install TWRP

[BadCluster]

--------------------------------> DISCLAIMER: <------------------------------------​

Guide for pure educational purpose. If you are going to use it, you do it to *your risk and danger, I will not be held responsible if your phone will not work anymore.

Depending on the phone manufacturer, root and unlock the bootloader could invalidate the warranty of the phone​

-------------------------------> PRE-REQUIREMENTS <---------------------------------​

ADB means Android Debug Bridge, and it is software that you should always do have installed on your PC.

Pre-Requisite 1
Make sure that you have the drivers for your phone installed on your PC.
If not, you can download and install them from here https://devsjournal.com/usb-drivers-for-all-android-devices.html or from attachment:

Pre-Requisite 2
You must also install: Minimal ADB & Fastboot, you can download the software
from here https://devsjournal.com/download-minimal-adb-fastboot-tool.html or from attachment:
Scrolling through the page you will have 2 options: Download or Portable
(choose the one that you prefer)

Pre-Requisite 3
Make sure you have enabled 'USB Debugging' and OEM Unlocking on your device (read all tutorial before do it, because it will be wiped all data from the phone)
Settings -> Applications -> Developer Options
Settings -> Applications -> Development

PAY ATTENTION: If you do not see the Developer Options menu you need to do this:
Settings -> Device Info -> tap 6 or 7 times on the 'Build version' entry
A pop-up should appear, telling you 'now you are a developer'

In case of disaster follow this tutorial:​

Restore Stock Image and Lock the Bootloader (for Warranty)​

-------------------------------> UNLOCK BOOTLOADER <---------------------------------​

IMPORTANT NOTE: Before doing this, know that this operation completely reset your device and after rebooting, you will find the phone as if he had just left out of the box. So you'll need to configure your phone again and reinstall all apps.

To unlock bootloader tap on:
Settings -> Applications -> Developer Options

(If you don't see the delevopers option you need to un-hide. To activate developer option click 7 times on ZUI version under settings -> system -> about. Once you did that you get developer options in settings -> system)

Now Click on it (Developers option) and activate the options OEM unlocking and USB debugging

If you have a Pin or Password, it will ask you to re-enter it.
You will see a popup where you will be asked to confirm this operation.

Now start the phone in boolader by doing this:

1) Connect the phone to the PC
2) Start the Minimal ADB & Fastboot program from the PC
3) On the PC screen, type:

adb reboot bootloader​

(A request may appear on the phone screen with permission of USB debugging, accept it)

The phone will now restart in Booloader mode.

4) Now that you are in bootloader mode, from the PC, from the screen
Minimal ADB and Fastboot type:

fastboot -i 0x2b4c oem unlock-go​

The response will look like this:

...
OKAY [ 0.031s]
finished. total time: 0.031s
C:\adb>​

Type:

fastboot reboot​

Now, during the reboot phase, the phone will proceed with a factory reset and will restart normally (it could take a couple of minutes)​

Done, now your phone has the bootloader unlocked.

-------------------------------> HOW TO INSTALL TWRP <---------------------------------​

Download the TWRP from here or mirror

1) Open the folder where your TWRP Recovery .img file is saved.

2)Then open a CMD window inside that folder. To do that, Shift + Right click on any empty white space inside the folder and then select Open command window here.

3) Connect your Android device to the PC. Type the following into the command window to boot your device into bootloader/fastboot mode:

adb reboot bootloader​

If your asks for permission to “Allow USB debugging”, tap OK.

4) Once your device boots into bootloader mode, type this into the command line.

fastboot flash recovery recovery-TWRP-3.2.3-0110-LENOVO_Z5PRO-CN-wzsx150​

5) Once TWRP is successfully flashed on your device, type this final command to reboot your device.

fastboot reboot​

Well, now you have installed the TWRP Recovery.

If you are interested to know how to root your phone: Follow this TUTORIAL

 

[hohoim]

HOW TO INSTALL TWRP no.2

I can't find cmd.
I can only see the power shell

 

[BadCluster]

HOW TO INSTALL TWRP no.2

I can't find cmd.
I can only see the power shell

because you are using win 10, inside the option there is "use powershell instead cmd" of something about that, uncheck it!

 

[hohoim]

Can you push it with original rom like Xiaomi Mi flash?

because you are using win 10, inside the option there is "use powershell instead cmd" of something about that, uncheck it!

thank you

 

[nerak11111]

because you are using win 10, inside the option there is "use powershell instead cmd" of something about that, uncheck it!

i need help, i cant unlock bootloader a have 10.0.355 version firmware

 

[manzza]

i need help, i cant unlock bootloader a have 10.0.355 version firmware

im on the same firmware, I'm able to input the adb reboot bootloader command and the phone loads in to the bootloader mode but after my pc doesnt recognise the phone, and when i input the fastboot -i 0x2b4c oem unlock-go, nothing happens and it displays waiting for any device,

i think the problem is that after the phone load in to the bootloader mode, the doesnt recognize it anymore so i cant send any commands to it,

can you help please,

 

[anonOmattie]

i found a way to lock the bootloader after you installed the original rom!

this will solve the < waiting for devices > error when phone is connected to pc

follow this tutorial to install the propper driver if your PC does not recognize the phone in fastboot: tutorial

how do i know if i need this?
to know if the proper drivers are installed open adb and type "adb devices" to see if your device is connected
if your device is connected and seen by adb, proceed to type "fastboot devices". if your device is recognized, you are good to go, if not, please follow the youtube tutorial as it helped me solve this problem.

when your device is read as a adb fastboot device, reboot into bootloader using "adb reboot bootloader"
after this, type "fastboot flashing lock" to relock your device. you will get a message on the device to ask for permission.
BE AWARE! THIS WILL WIPE YOUR PHONE TO FACTORY RESET!

this steps will probably also help to unlock the bootloader in version355, but i have not tried that. please leave your findings below if you tried this!

 

[SrCDA]

does it work with lenovo z5 pro gt?

 

[Ace3412]

Thanks man i will try this as soon as they deliver my phone still waiting on it.

 

[vinashiny]

[/COLOR]

i found a way to lock the bootloader after you installed the original rom!

this will solve the < waiting for devices > error when phone is connected to pc

follow this tutorial to install the propper driver if your PC does not recognize the phone in fastboot:

how do i know if i need this?
to know if the proper drivers are installed open adb and type "adb devices" to see if your device is connected
if your device is connected and seen by adb, proceed to type "fastboot devices". if your device is recognized, you are good to go, if not, please follow the youtube tutorial as it helped me solve this problem.

when your device is read as a adb fastboot device, reboot into bootloader using "adb reboot bootloader"
after this, type "fastboot flashing lock" to relock your device. you will get a message on the device to ask for permission.
BE AWARE! THIS WILL WIPE YOUR PHONE TO FACTORY RESET!

this steps will probably also help to unlock the bootloader in version355, but i have not tried that. please leave your findings below if you tried this!

I tried, But I can't.

ver: 355

C:\Program Files (x86)\Minimal ADB and Fastboot>adb devices
List of devices attached
* daemon not running; starting now at tcp:5037
* daemon started successfully
c4aec27a        device


C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot devices

C:\Program Files (x86)\Minimal ADB and Fastboot>adb reboot bootloader

C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot flashing lock
...
FAILED (remote:         Device already : locked!)
finished. total time: 0.012s

C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot flashing lock
...
FAILED (remote:         Device already : locked!)
finished. total time: 0.059s

 

[anonOmattie]

does it work with lenovo z5 pro gt?

i am not sure, but except for cpu the phones are similar. you can try the steps i provided and see if it will lock. no chance of bricking your phone if following shown commands.
please reply if this work!

[/COLOR]
I tried, But I can't.
ver: 355

C:\Program Files (x86)\Minimal ADB and Fastboot>adb devices
List of devices attached
* daemon not running; starting now at tcp:5037
* daemon started successfully
c4aec27a        device
[B]------------phone is seen by adb as device[/B]

C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot devices
[B]-------------phone is not seen as fastboot device, so follow tutorial provided[/B]

C:\Program Files (x86)\Minimal ADB and Fastboot>adb reboot bootloader

C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot flashing lock
...
[B]FAILED (remote:         Device already : locked!)[/B]
[B]------------why try to lock a already locked phone??[/B]
finished. total time: 0.012s
[/QUOTE]

 

[maxihinz]

How do I update the OS once i've unlocked the bootloader and rooted?
Do i just simply install the zip update via TWRP? Or do i need to flash it with the qualcomm flashing tool?

 

[Blade_zheng]

I have activate the oem , but in th bootloader it still show that the oem is failed ,it means it haven't turn on the button i don't know why i can't unlock the oem

 

[anonOmattie]

How do I update the OS once i've unlocked the bootloader and rooted?
Do i just simply install the zip update via TWRP? Or do i need to flash it with the qualcomm flashing tool?

you should wait for the rom to be updated, and flash it with qfil flasher. there are currently nop twrp roms available...

I have activate the oem , but in th bootloader it still show that the oem is failed ,it means it haven't turn on the button i don't know why i can't unlock the oem

so you want to open or close bootloader?

 

[Blade_zheng]

you should wait for the rom to be updated, and flash it with qfil flasher. there are currently nop twrp roms available...



so you want to open or close bootloader?

I will be wait.i want to open the bootloader

 

[ndama]

doesnt work for me, it only shows :

< waiting for any device >

and nothing happens, did i miss a step ? should i do something on the bootloader menu ?

 

[ndama]

i found a way to lock the bootloader after you installed the original rom!

this will solve the < waiting for devices > error when phone is connected to pc

follow this tutorial to install the propper driver if your PC does not recognize the phone in fastboot:

i did this
still gives me the dreadful waiting for any device message

 

[GorranKurd]

Does NOT work on Win 10!!

It can Reboot to the Bootloader but cant Unlock it always is Say < waiting for any device > and nothing happen....

 

[crwm74b4x]

I have a Lenovo Z5 Pro, firmware 10.0.355, bootloader unlocked and TWRP (no root).
Can I flash the OTA update (I received the 10.5.153 - Android 9.0 OTA update) with the TWRP or I must flash again the original recovery?

If I need the original recovery, anyone knows where I can download the original one (10.0.355).

Thank you.

 

[wolfgart]

what about TWRP for Z5 Pro GT 855 version ??