I cannot get into it. No ping, no telnet, no tftp....destination unreachable. I'm not super smart in this area so forgive my ignorance if this has a simple fix....
Background:
I was upgrading the firmware form 2.07.1 to 4.70.6 through the upgrade firmware function.
The unit froze, for nearly 20 minutes, before I rebooted it. At first it wouldn't allow anything to see it. then after pushing the reset button, I could ping it but could not get into the admin area. The power light was flashing through all of this along with the DMZ light slowly coming on and off. I then tried to reload the firmware using tftp, got it loaded and was able to get in set it up....it was working.....then 3 days later it locked up, no connect, no nothing....Its back to the power light flashing and DMZ slowly going on and off. Any help would greatly be appreciated. Thank you, ss123

do serial mod and make nvram erase in terminal...

Ciao Gerd

While the other poster's suggestion of a serial adapter would work, I found a jtag cable *always* works and costs about 1/6th as a serial adapter to aquire. 

It also works in all situations.  You can even blow the CFE away and recover with JTAG.

JS

PS - There are no bricks until the magic smoke comes pouring out.