Failed -remote 39-flashing Lock Flag Is Locked. Please Unlock It First 39-- Jun 2026

: Most devices ship with a locked bootloader to ensure the device remains in a state produced by the manufacturer (OEM).

Confirm your screen switches to Fastboot Mode. Test the connection by typing: fastboot devices Use code with caution.

On the left-hand menu, click on the "Option Bytes" tab (represented by a memory chip icon).

: You are attempting to run a flashing command (e.g., fastboot flash boot boot.img ) before executing the final validation commands on the terminal. Step-by-Step Fixes to Unlock the Flashing Lock Flag Step 1: Enable Necessary Android Developer Settings : Most devices ship with a locked bootloader

Xiaomi uses a separate unlock process because of the "lock flag" being tied to their servers.

The chip might have been programmed in a previous project to be locked, preventing debugging.

Some partitions are more protected than others. For example, you may be able to flash the boot partition after a standard unlock but not the bootloader partition. If you're having trouble with a specific partition, try unlocking critical partitions using the fastboot flashing unlock_critical command, as that is designed to grant access to these low-level areas [13†L10-L11]. On the left-hand menu, click on the "Option

Some carrier-locked phones (like those from Verizon or AT&T) do not allow bootloader unlocking. In these cases, there is often no official way to bypass the "flashing lock flag."

(Replace stm32f1x with your specific chip series, e.g., stm32f4x ) . What to Do If Level 2 Lock Is Applied

Use this variant if you are targeting core hardware files like the bootloader layout or partition tables. Step 4: Confirm Unlocking on the Phone Hardware The chip might have been programmed in a

Tap (or MIUI Version on Xiaomi) 7 times to enable Developer Options.

If the is active, the smartphone protects its partitions (such as boot , system , or recovery ) from being overwritten. This mechanism prevents unauthorized malware or custom firmware packages from compromising the hardware. Root Causes