[LeEco Le Pro3 Questions & Answers] tsongming:
Unlock Bootloader - Le Eco Pro 3

If you are not seeing your phone ID in ADB

Did you enable enable Developer options, or chosen MTP?

Its possible that the Android driver driver is outdated, or just try another usb port, preferably in the back of the machine.

Go here to check a whole list of possible causes: https://appuals.com/android-phone-not-showing-up-on-pc/

More than you asked for:

Since you seem to be new to your Leeco phone and new to using custom roms, I am going to go ahead and answer your current question and provide you steps needed to move forward. No big deal, I just copy pasted my notes ( with a few edits)

First steps that you need to take:

1. You will first need to unlock the bootloader :

https://xdaforums.com/showpost.php?p=71566961&postcount=203

2. Install Twrp :

https://twrp.me/leeco/leecolepro3.html

****** Scroll down to see: Fastboot Install Method (

3. Right now just use ADB. But for the future, I highly recommend that you buy an OTG drive: it makes the whole process a thousand times easier: They are cheap somewhere near $5 and worth ten times that

Unlocking the Bootloader

You can save your self alot of time by looking up how to give ADB system wide privileges: this will allow you to flash files without tying the directory path.

Mauronofrio created a tool called: "TOOL ALL IN ONE"" it's great, install it and check for updates.

https://toolaio.tk

The all is one tool is excellent and you can use it to install everything if wanted.

I usually recommend it for novices that can use it to help with unlocking the bootloader and installing TWRP.

The tool will also update your copy of ADB, android Drivers and provide system wide privileges for ADB

LETS RECAP : Choose using the All in One Tool or the ADB Method

**********BEFORE DOING ANYTHING*******************

Make sure you have enabled the developer tools,

Turned on USB debugging

Authorized your computer on your device I.E: “MTP”

Make sure the All in One Tool can see your device

(*) Select your device from the drop down menu, then click check

(*) Choose to install drivers, and set ADB and fastboot privileges from advanced menu.

(*) First attempt to unlock, then check bootloader status

If you have a X727 you will need to flash : emmc_appsboot.mbn from this zip :

https://androidfilehost.com/?fid=313042859668275431

Next, choose Recovery flasher and manually select your copy of TWRP

After you have received the success message, I recommend doing the rest of the install manually within Twrp Recovery.

(*) Reboot into TWRP and begin installation of your Rom, Gapps and Magisk.

Using the ADB Method

Install ADB/Fastboot tools on your computer

https://wiki.lineageos.org/adb_fastboot_guide.html

1. Make sure you have enabled the developer tools,

2. Turned on USB debugging, and authorized your computer on your device “MTP”

3. Enter fastboot mode on phone (hold power and VOL -)

4. Make sure adb can see your device when you run "adb devices"

5. type: fastboot devices

6. fastboot flash aboot emmc_appsboot.mbn

7. Run { adb reboot bootloader } - No spaces (before/after)

8. Run { fastboot devices } to make sure you see your device

9. Run { fastboot oem unlock-go } to unlock your device temporarily

10. Run { fastboot oem device-info } to verify unlock status

11. Run { fastboot boot recovery_twrp-3.2.1-0-zl1.img }

12. 5. Reboot back to TWRP and begin installation of your Rom, Gapps and Magisk.

13. 6. If you wiped data, your device will now proceed to re-initialize itself as if from the factory

Concerning your device's storage,

When you boot into twrp you will see a message that states that the storage is encrypted.

*****************Important************************ ******************

Ensure that you have TWRP installed as the primary recovery

Ensure that you have TWRP installed as the primary recovery

Ensure that you have TWRP installed as the primary recovery

Ensure that you have TWRP installed as the primary recovery

To remove encryption you will need to format the storage

(Anyone who says otherwise has the X720 and not the X727)

You could also try to skip the formatting step. But you will very likely have permissions issues and get errors and you will eventually have to come back and format ( Again as long as Twrp recovery is install there is very slim chance of ever bricking your phone.

To format the storage

Go to Wipe, choose Format Data and follow the instructions.

This will erase all of photos , music, etc

If you wiped your data partition, you'll need to push the zip file to the newly formatted storage. - This is one BIG reason why using OTG is better. You can use Mauronofrio's "TOOL ALL IN ONE"" for pushing the ROM, Gapps, and Magisk to storage.

Root: You absolutely should root!

NOTE: If you have unlocked the bootloader and flashed TWRP to the recovery partition. But have not yet flashed a Custom Rom the OS will likely reset back to the factory recovery UNLESS YOU ROOT THE SYSTEM. Your device is still unlocked. But the recovery can be overwritten by the stock EUI system, so beware.

Installation of Rom, Gapps, Magisk

Boot into TWRP recovery

1.	Go to "Wipe" and then to "Advanced Wipe".

2.	Mark "Dalvik / ART Cache", "System", "Data" and "Cache".

3.	"Swipe to Wipe" and proceed back the main menu.

4.	Go to "Install".

5.	Select the ROM zip file and then press "Add more Zips" and select the Gapps zip file, and then the Magisk file.

6.	"Swipe to confirm Flash" and wait for some time.

7.	After the flashing is finished, just reboot to system.

Finished!

If you need help or have a question message me, I would much rather help you with a successful install versus helping you unbrick your phone.