How To Flash HTC Desire Dual Sim 820U Firmware
- For product: a51_dtul
- Firmware Download: here
- Note: File download must not unpack
Install fastboot drivers from below if you have not previously installed.
If using Windows 8 / 8.1 / 10, be sure to disable the driver signature check before installing drivers.
Download tool fastboot unzip
Now put in the downloaded zip in the same folder “fastboot.exe” and rename it to “firmware.zip”
Open a command window in the current directory
(Shift + Right Click on the folder and then select “Open Command Window Here”)
Boot into fastboot mode (Vol down + Power then select fastboot)
Now type the following commands.
1.Fastboot OEM lock
2. (If Bootloader Unlocked previously been if not ignored)
Wait out logo HTC
fastboot flash zip firmware.zip
Wait too finished