my ATP700 does not boot anymore

adischer

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-

PeterUK

Sounds like you did not update firmware with the an older firmware bug that can cause this.

Recovery Steps for USG FLEX/ATP Series Application Patrol Signature Issue — Zyxel Community

https://community.zyxel.com/en/discussion/13012/failed-to-upgrade-to-the-new-zld5-21-patch-1-why-and-how-to-resolve-it#latest

PeterUK

Sounds like you did not update firmware with the an older firmware bug that can cause this.

Recovery Steps for USG FLEX/ATP Series Application Patrol Signature Issue — Zyxel Community

https://community.zyxel.com/en/discussion/13012/failed-to-upgrade-to-the-new-zld5-21-patch-1-why-and-how-to-resolve-it#latest

adischer

Thank's so much PeterUK.....yes you were right. this seems to have been the issue. I was running 5.20 firmware. using the link you provided I was able to recover the system using the backup partition which was still on 5.10. Booting up and also using the password reset trick mentioned in one of the links inside the link you provided I was able to install firmware 5.21 and set back the device into normal operations. 
i am really happy this was just a firmware and not a hardware issue. 
great support here !