I have seen couple threads that some users flashed the phone with COMBINATION_FAC_FA60_A520FXXU3AQL1 for frp reset and afterwards they couldn't find Binary 3 Firmware..
Here is Binary 3 Firmware:
A520FXXU3BQLA - 7.0 - SER(Russia) - Multi Firmware + PIT.zip
no password... Enjoy
After flash combination file, enable USB debug and flash again with stock firmware just remember let empty CP and choose HOME for CSC file.