Can't Access NAS - Please Help!

[javalawyer]

I have a Asustor Drivestor 4 Pro AS3304T and after 6 months the NAS disappeared from my network. It no longer shows up in my Router and the "Control Center" software doesn't find the NAS. IDK how to access my 80TB of data. I tried attaching the NAS to my PC via local ethernet and nothing shows up. I tried putting a pin in the hold in the back and holding to reset, but it still doesn't show up in my NW or on my PC. Please help.

[snapshot]

You may have a hardware fault so there's nothing we can do here. Please raise a support ticket with Asustor.