This is the golden rule of Android modification. While simply entering Bootloader mode does not delete data, subsequent actions (like unlocking) certainly will. Connect your tablet to a PC and copy all photos, documents, and important files to a safe folder.
Manipulating the bootloader is an advanced procedure. Before proceeding, you must acknowledge the risks: How to Open Bootloader Mode on TECLAST New P40HD
If your buttons are not working or you are already performing developer tasks, you can use Android Debug Bridge (ADB) . This is the golden rule of Android modification
This comprehensive guide will walk you through everything you need to know about the TECLAST New P40HD bootloader. We will cover what a bootloader is, the crucial prerequisites you must complete before starting, the standard methods to access the mode, and a specific discussion on the unlocked status of TECLAST devices. Manipulating the bootloader is an advanced procedure