| Problem | Solution | | :--- | :--- | | | The P40HD has no volume keys? Use Method 2 (ADB) only. | | PC doesn't detect device | Install the Unisoc USB drivers or Google USB Driver . | | Tablet boots normally | You held the wrong key. Try Volume Up + Power instead. | | "Not allowed to unlock" | Go to Developer Options and toggle "OEM Unlocking" to ON. |
Opening the Bootloader Mode on the TECLAST New P40HD is not as straightforward as on a Google Pixel or OnePlus device, but it is entirely possible. The proven path is using adb reboot bootloader after enabling USB Debugging and OEM Unlocking. The hardware key method (Volume Down + Power) serves as a reliable backup when Android is unresponsive.
: Press and hold the Power and Volume Down buttons simultaneously. Release Buttons :
Type the following command and press Enter:
Some P40HD units have a hidden engineering menu: