If WDRT fails, you can try manually flashing the phone using the thor2 command-line tool, which is installed alongside WDRT: Lumia 650 User Guide - Microsoft
Finding your Microsoft Lumia 650 stuck in a boot loop, displaying a black screen, or showing the dreaded "Emergency Calls Only" error can be frustrating. When a smartphone enters this state, it is often "bricked" due to corrupted firmware. lumia 650 emergency files fix
guides/WIP-NewGuide.md at master · WOA-Project ... - GitHub If WDRT fails, you can try manually flashing