Flash Image not works - Sunray mini pro

Hello, I would like to flash an OpenPli Image to my sunray mini Pro v2, because i think someone changed the name and password to access it via ftp. I Follow the guide, i put the image folder in the usb, i turn on the decoder but it automatically starts with the installed image (OpenPli) and the usb doesn't start.
I tried with differents usb pens, and I tries with a serial-usb cable using vutil, but it says restart or connect your decoder.
Help please