my ATP700 does not boot anymore

Hi, after a power outage, my ATP 700 does not boot anymore.
Eventually, I could connect to the device using the serial port (ordering a serial device that can connect to my Mac using Thunderbolt and installing a terminal program). I could see the boot up message of the ATP700.....everything looks very normal in the log. It checks the DRAM, starts certain daemons and the ultimately checks the antivirus signature package. At the next message "load av threat info" it gets stuck forever.  the CLI handbook says I should only initiate the recovery process in debug mode if a message like "invalid recovery image" or "invalid firmware" shows. however, this is not the case here. before I do anything else and kill the device entirely I thought I ask the question here first what to do......the ATP 700 is definitely stuck, does not get an IP and I can only connect via serial port to get any info at all. 
The Sys LED keeps on blinking for ever. 
Please help-