connect via console cable, get serial

 get system | i serial


!!! Lost Password Reset !!! You have initiated a command to reset the device to factory defaults, clearing all current configuration and settings. Would you like to continue?  y/[n]

!! Reconfirm Lost Password Reset !! If you continue, the entire configuration of the device will be erased. In addition, a permanent counter will be incremented to signify that this device has been reset. This is your last chance to cancel this command. If you proceed, the device will return to factory default configuration, which is: System IP: x.x.x.x; username: netscreen, password: netscreen. Would you like to continue?  y/[n] y

In reset …

login as a netscreen/netscreen