This page is containing the official link to download OPPO all models NVRAM files and QCN files. Basically, these OPPO NVRAM and QCN files is used for repair network and repair imei. If phone has null imei and no imei show you can repair by these OPPO NV DATA files. This files is introduced with a zip package.
HERE YOU CAN DOWNLOAD PREMIUM OPPO NVRAM AND QCN FILES