If your Tecno i7 mobile is rebooting itself repeatedly or not turning on at all, then it is possible that the system has crashed. In such a situation, using the DA file becomes necessary because this file allows you to bypass the security of the mobile and repair it using the SP Flash Tool. Sometimes when the mobile becomes completely dead, that is, it does not turn on at all, and does not connect to USB, then ordinary users think that the mobile is completely damaged. But in MediaTek phones like Tecno i7, such a mobile can be revived using the DA file.
If the Tecno i7 mobile connects to USB during flashing but is not detected in SP Flash Tool, then it means that the phone has Secure Boot enabled. In such a situation, you have to bypass this security by using the DA file. Some MediaTek devices like Tecno i7 get an "authentication required" error while flashing. A specific DA file is used to resolve this error so that the mobile can be flashed securely.