Android 7 Nougat is finally available for ZUK Z2 thanks to the famous ROM CyanogenMod, or rather the new one Lineage OS. The ROM is not bug free - but these are little things that I will list later - but it is updated frequently and the bugs are solved quickly.
The guide will explain each step in detail: unlock bootloader, TWRP flash recovery and installation Lineage OS 14.1 on ZUK Z2; ROM based on Android 7.1.1. By carefully following the steps, your smartphone will not suffer any damage; the responsibility is still of the reader.
NOTE: : There are two variants of the Lenovo ZUK Z2: the version Plus and the version Pro. They differ in several respects. In this guide we are talking about ZUK Z2 Plus (known simply as ZUK Z2), the model with 4 GB di RAM e 64 GB of internal memory so to speak. If your device is a ZUK Z2 PRO, you can only use the part related to unlocking the bootloader.
Before starting, I invite you to read the guide carefully. For any questions, do not hesitate to ask in the comments.
Unlock bootloader ZUK Z2
NOTE: : This procedure will format the device. Back up your data before you begin.
What is needed?
- PC Windows
- Telephone charged> 90%
- USB debugging | from the smartphone go to Settings -> About and click repeatedly on Build number until a message tells you that Developer Options is active. So go in Settings -> Advanced Settings -> Developer Options and activate the voice USB Debugging
- ZUK driver | Connecting the smartphone to the PC, a ZUK application driver installation will start. It is important, before proceeding, to stop the automatic driver installation via Windows Update.
- adb | download for free and install by answering "Y" to all questions
- Serial number | go in Settings -> About -> Status and scroll to Serial number; you will find a code that can be composed from 6 to 8 digits. Save it somewhere, it will be necessary later.
If you have done the above, you can connect the smartphone to the PC via USB cable.
- A message will appear on the phone display asking you to accept the communication via adb; accepted.
- Now go to the adb installation folder and hold down the SHIFT key, click on the right mouse button. The classic drop-down menu will open where you need to select Open command window here
- At this point, to verify the connection, type the following command in the new window:
After a few seconds you should read a "List of devices attached" message with the serial number copied previously. In this case, you can continue with the guide, otherwise you will need to repeat the driver installation.
- Now type the following command to enter the bootloader (or fastboot)
adb reboot bootloader
Now that the phone has rebooted and is in fastboot, we can proceed with unlocking the bootloader. If you do not have a ZUK account, first go to the site to register. | Link
Arm yourself with Google Chrome since the site is in Chinese, then translate the page and click on Mail registration to create an account by email rather than by phone number. Then wait for the email and click on the link to confirm it. After that, go to the site to ask for the bootloader to be unlocked. | Link
Also translate this page and scroll down, then click on continue. On the next page, fill in all the fields with telephone, serial and email type.
Note: in the series field, you will have to enter the serial number copied previously: if this is composed of 8 digits, simply enter it; if it is composed of 6, add two zeros at the end (00); if composed of 7 digits, add a zero at the end (0).
At this point, accept the terms and click on present and will ask you to log in; enter the credentials created just before on the first site. Within a few minutes you will receive the email with the file for the release. Save the attachment and move it to the adb folder. Go back to the command window and type the following commands.
fastboot -i 0x2b4c flash unlock unlock_bootloader.img
Wait a few seconds for the operation to finish and after the confirmation message use this last command (format the phone):
fastboot -i 0x2b4c oem unlock-go
A confirmation message will notify you of the release and the phone will restart. You can disconnect the USB cable. The bootloader is unlocked.
NOTE: : Each time you turn on your smartphone, a new warning screen will now be shown. Ignore it and after 5 seconds it will start.
ZUK Z2 recovery TWRP
Now that the bootloader is unlocked, we can proceed with the second step, which involves the installation of a custom recovery, or TWRP.
What is needed?
- Recovery | Download
- Open the zip file and extract it where you prefer, inside there will be a file with a name similar to this one
- Rename to recovery.img, then copy the file to the adb folder
- Connect the phone to the PC via USB and go to the adb folder (USB debugging must be active)
- Holding down the SHIFT key, click on the right mouse button and choose Open a command window here
- type adb devices to verify that the phone is communicating with adb (as done previously - adb will show the serial)
- If the phone has been recognized, we can continue with the commands
- Restart in fastboot with the following command
adb reboot bootloader
- Then flash recovery with this command
fastboot -i 0x2b4c flash recovery recovery.img
When finished you can disconnect the USB cable. The recovery that we have just installed is in Chinese, so you have to change language.
- Press and hold the power button to restart the phone
- You will still see the new warning screen that the phone is unlocked
- Press one of the volume keys before the 5 seconds, a new screen will appear
- Move with the volume down button to Recovery, then press the power button to select
- The warning screen will appear again, wait for the 5 seconds and the recovery will start
- Once in recovery mode, we will find two keys in the middle, plug the one to the right and choose English
- Now, coming back, you will notice that the first key will be used to leave the system read-only. Don't crush it
- Check the message Never show this screen during boot again and make the swipe (image below)
- Now select the reboot item and select recovery again; a message will ask you if you want to allow to overwrite the TWRP recovery with that stock. Deny and restart in system
Install Lineage OS 14.1 on ZUK Z2, GApps and ROOT (optional)
Now everything is finally ready and we can install the new ROM based on Android 7.1.1! As already mentioned, it is about Lineage OS (or CM if you prefer), but the procedure is the same for almost all custom ROMs. This is the simplest procedure and you can proceed from the phone without using the PC.
What is needed
- ROM Lineage OS | Link - here you will find the discussion with bugs, fixes, etc. At the moment the ROM is at the 4 version.
- GApps | Download - select ARM64 -> 7.1 -> pico
- root (optional) | Download - not updated from the Play Store or you will have a bootloop
- You MUST NOT unpack any files
What is not working
- Video recording. It resolves with Footej Camera from the Play Store
- At start-up, the time and date are incorrect. It resolves automatically after a few seconds
- Hotspot. No solution at the moment
As mentioned above, the bugs are few and almost irrelevant. In concrete the only real bug is the hotspot, but the developer is working on it.
- Download ROM and GApps (also root if you want) on your phone. You should find them in the Downloads folder.
- Restart the phone and enter recovery as before
- Choose the item Wipe and confirm by swipe the wipe data / factory reset
- Now go back and choose install, then move to the folder where you downloaded the ROM and select it
- You can add other zip files to the installation queue: choose the GApps (and the root if you have downloaded it).
- Confirm the installation by swipe down and wait a few minutes.
- When finished, select reboot -> system and wait a few more minutes.
The first start will put us more than usual, but in the end you'll have thelatest Android version on your ZUK Z2!
Something does not work?
I found some small problems during use, here are some workarounds. If you find other problems, I invite you to report them.
- Crash browser stock. Turn it off and use Chrome
- Youtube may not work. Used this app as an alternative
- Drain battery. From the battery settings the Automatic optimization is enabled