ReadyNAS Pro VPD issue?

Hi,
any jedi knight willing to help me...mdgm?

Having upgraded 3 RNPDP6xxx to OS 6.6.0, two of them are ok but I guess one has a VPD problem.
Model, Serial is shown garbeled in RAIDar 6.2. Offline Setup gives me an "Error Reporter Communication Error".

The System was USB recovered with a handmade OS 6.6.0 key :smileywink: because it was stuck on the display with ReadyNAS (no boot menu accessible). After recovering the system it did work but not showing Model and S/N on the Adminpage.
I was able to create Volumes, install add-ons just worked...

Trying to fix this I inserted a single disk and tried factory default and os reinstall but had no luck. RAIDair shows it as new device but trying to configure it (Offline Setup) gives me the "Communication Error".
Also recovery does not help anymore. Same result.

System is not reachable from outside. Techsupport displays "DebugMode[63527] 0.0.0.0"

Any help will be appreciated!