To flash or unlock devices, you often need specific DA (Download Agent) and Auth (Authentication) files because these MediaTek-based models feature a Secure Boot system. Without these files, standard flashing tools will return a "BROM Exception" error. 1. Download Required Files
: Install the latest MediaTek (MTK) USB Drivers on your PC. Battery : Ensure your device has at least 50% charge . To flash or unlock devices, you often need
: Use a modified version of SP Flash Tool or professional boxes like NCK Box or Miracle Box . 3. How to Use Auth Files in SP Flash Tool Download Required Files : Install the latest MediaTek
You can find the specific archive mentioned at the Up4ever download page VIVO Y93 Y91 Y91i Y91C DA & auth File By Firmware4mobile.com.rar". Other reliable sources for these files include: : VIVO Y91 Y91i Y93 Auth & DA.zip. GSM Firmware : Vivo PD1818CF DA+Auth Files . 2. Pre-requisites perform a full backup if possible.
: Flashing will wipe all internal data; perform a full backup if possible.
