Unlock your vivo Y91 (Mediatek)

OS: Android 8.1 (Oreo); Funtouch 4.5

CPU: Octa-core 2.0 GHz Cortex-A53

Display: 6.22" inc

Camera: 13 MP, Dual

1. Use the Tenorshare 4uKey for Android app.
2. Make a hard reset (factory reset).
3. How to use a low battery to unlock a phone locked with a graphic key.
4. Delete 'gesture.key' and 'password.key' using Aroma File Manager.
5. Restore access to your smartphone using your Google Account.

1. Use the Tenorshare 4uKey for Android app.

Connect your phone to PC and open Tenorshare 4uKey for Android.
In the menu that appears on the PC screen, click Remove.
The program will warn you about deleting all data from the smartphone, to continue working, click OK.
After finishing the lock removal process, put your phone into recovery mode.
Click the Next button, then follow the steps recommended by the program to restore the device to factory settings and reboot it. After rebooting the smartphone, the screen lock will be disabled.

2. Make a hard reset (factory reset)

First, turn off your phone.Simultaneously press and hold for about 10-15 seconds one of the button combinations:
Volume down button + Power button;
Volume up button + Power button;
Volume down button + Power button + Home button;
Volume down button + Volume up button + Power button.
Using the volume up/down buttons to navigate through the menu options, select Recovery and press the power button.
Select Wipe data/factory reset. using volume up/down buttons to navigate through the menu and confirm selection by pressing the power button.
Finally, confirm the reset operation.

3. How to use a low battery to unlock a phone locked with a graphic key.

You need to make sure that the battery of the phone is discharged.
When the battery has a few percent left, the phone will report this and open the menu with power settings, that is, it will unlock the phone.
You need to open the menu with security settings and turn off the phone lock.

4. Delete 'gesture.key' and 'password.key' using Aroma File Manager.

You need to turn off the phone and remove the memory card from it.
Transfer the Aroma File Manager program using a computer to the phone's memory card. Insert the memory card back into the phone.
Using the combination of volume and power buttons, boot your smartphone into recovery mode.
In recovery mode, select the option Install zip -> Install zip from sdcard -> Choose zip from sdcard, go to the archive folder with this program and select it.
After starting the program, you will need to go to the folder /data/system and delete the files 'gesture.key' and 'password.key' (for Android 4.4 or lower) or 'getekeeper.password.key' and 'getekeeper.pattern.key' (for Android 5 or higher)
Reboot your smartphone. The screen lock will be released.

5. Restore access to your smartphone using your Google Account.

After several unsuccessful attempts to unlock the phone, the message Forgot password? will appear. Click on it.
You will need to enter your Google Account username and password.
Remove the screen lock from the settings.

Thomas Nilan
Smartphone Expert

Thomas Nilan is a mobile phone expert with in-depth knowledge of the Android and iOS operating systems, who understands the settings of various hidden features that allow you to expand the capabilities of your smartphone, as well as get information about what is going on inside the phone for future repairs. He is an authority in his field, which has allowed him to become a ghostwriter for several technology publications, and he enjoys writing small mobile applications for testing smartphones.