How to Hard reset and Unlock Bootloader Samsung Galaxy M21 without Trigger KG State / RMM state Prenormal. If you want to flash ROM, you need to unlock the bootloader, unlocking bootloader on Galaxy M21, it does not enough by enabling OEM unlock option although KG State / RMM State is not Prenormal and OEM unlock option is enabled. This method will wipe all data on internal storage. So, make sure to backup your important data! the data can not be recovered.
Step by step to Unlock Bootloader Galaxy M21 :
- Enable Developer Options: go to Settings -> About device. Tap 7 times on Build number to enable Developer options.
- Enable OEM unlock and USB debugging options ( Settings -> Developer options ) If OEM Unlocking option does not appear connect the phone to internet for a while until it appears.
- Download and Install Samsung Mobile Phone Drivers ( ignore this if you have installed it ) : http://developer.samsung.com/technical-doc/view.do?v=T000000117
How to unlock Bootloader Galaxy M21
- Turn Power off the phone, Press and hold Volume Down + Volume Up keys together then while pressing these keys connecting the phone to PC with USB Cable Data, release all keys when Warning screen appears
- In the Warning screen: long press Volume Up option to enter Device Unlock Mode. Unlock the bootloader ( that will wipe your device so be sure to backup of your data )
- Read description on the Unlock Bootloader screen then use Volume UP to select “YES” to confirm and “No” to cancel unlock bootloader and restart the phone.
- After Bootloader unlock, the phone will reboot .
- Setup the phone without google account etc.
- Connect the phone to Internet.
- DON’T RESTART OR POWER OFF until OEM unlocking option exists and grayed out! or triggers KG State / RMM State Prenormal.
- Enable Developer Options again: Go to Settings -> About device. Tap 7 times on Build number to enable Developer options
- Open Developer options If you can not see OEM Unlocking option then close Settings and wait for a moments
until it appears.
- After confirmed that OEM unlocking option exists and grayed out! Now you can Restart or Power off the phone
- The Bootloader are unlocked Now!
How to Hard reset Samsung Galaxy M21 ( normally + forgot pattern )
- Turn Power Off ( In case you forgot the pattern: press and hold Volume Down key + power key, when screen goes blank release volume down then quickly press and hold Volume up and power key jump to point 3 )
- Press and Hold Volume Up key + Power key
- When Samsung logo appears release power key only, keep pressing Volume Up until Android Recovery appears
- Select Wipe data / factory reset
- Press Power key to confirm
Notes / Warning!
- Use at your own risk, I’m not responsible for bricking your device.
- Make sure to backup your important data before unlock the boot loader.