Zywall ATP 100 Firewall Not Booting

WillFarmer

Hello! Our company recently acquired some Zyxel devices we are setting up in Nebula and everything was going good until a month ago or so. We have 3 ATP100 devices that were working, Now only 1 of the 3 is now working, The 2 are not showing connected in Nebula.

During troubleshooting, I noticed the interfaces on either Firewall were not coming up. I did some googling and found a reset may work on this but unfortunately holding the reset button doesn't do anything on the devices. The power light is a solid green but SYS light is blinking green. I hooked up a console cable to both of them as well but it's not showing any output on my putty screen it's really odd. I was out but I was told these ATPs were all upgraded to the latest firmware and they were working afterward but now they are not. Is there anything else we can try before we attempt to get them RMA'd? 

Thank you!

Zyxel_Cooldia

Hi @WillFarmer,
It could be related to App signature issue. If your device cannot boot up successfully. 
Please follow the link below to recovery device.
https://community.zyxel.com/en/discussion/12943/recovery-steps-for-usg-flex-atp-series-application-patrol-signature-issue/p1