plugin console cable with known port open in Putty.
Eject the CF and copy firmware and rommon to it, or get it on the device via USB or TFTP etc.
Power on and “Ctrl+( right click putty > special command > break ) ” – repeat until
rommon 1 > confreg 0x2142 You must reset or power cycle for new config to take effect rommon 2 > reset
upgrade rom-monitor file flash0:\"file name"
after rommon upgraded del flash0:/”all firmware but the newest bin” and reload
config t config-register 0x2102 end erase nvram: copy run start