My method for unbrick redmi note 3 pro using a deep flash cable: Unbrick Redmi Note 3 PRO from Hard Brick using a deep flash cable-Skip Testpoint - Redmi Note 3 - Xiaomi MIUI Official Forum
I had same problem as GR_Macedon and chat1978. I finally un-bricked my phone after 2 days. I can post my method here(home made deep cable not test point) if you want but I don't know greece language. So, if some one can translate my post I will help you without problems. If not, I will post anyway to miui forum and I will send you a link. Regards