Once the Oppo Flash Tool or QFIL reports success:

Download the Oppo A57 CPH1701EX-11-A.35 zip package and extract it to a folder on your desktop using WinRAR or 7-Zip. Step 2: Install Drivers

The Oppo A57 uses a Qualcomm chipset, which means the flashing process typically involves the MSM Download Tool or a similar Qualcomm flash utility. Step 1: Extract the Firmware

Here’s everything you need to know about this specific firmware release.

. In the mobile repair community, "flash file" refers to the official firmware used to repair software issues, such as a device being stuck on the logo or a "dead boot".