Firmware Wi 9210 me not update

I have un instrument climet with WI 9210 ME unit. I try to upload a official firmware for update from 1.20 to 1.28 by FTP image.bin update. When I transfer file flash RAM not start and firmware not update. Exit a image that flash nvram without Lost FTP connection? My idea Is flash nvram and after upload a correct image.bin. It possibile or riso brik the unit?