Vinod,
Without console access it makes it hard to attempt to recover, passwords, configs,etc.. if you knew atleast its IP addresses from the inside interface you could perhaps telnet or http to the inside port, but you are indicating that you don't have any info about this device.
Even if you try to use a network sniffer and mirror the inside interface to capture/decode some of its pacekts to see an IP address but may not work and if it did you are still left with the need to know the admin password.
It would be best if you have Cisco service contract to RMA it to get a replacement, if not you can google vpn3000 repairs , perhaps you may have some luck from a copany out there that repairs network equipment, but all these is not worth the effort as you can prety much pick up a vpn3005 device for couple of hundred bucks on ebay.
Rgds
Jorge
Jorge Rodriguez
