Duo V2 with defect networkcard and no backup

Its possible that you could move your existing 2x2TB disks to another Duo v2 chassis and be able to retrieve the data as long as you put the drives accordingly to which bay you have pulled it out from the faulty Duo v2 chassis.

If ever that your other Duo v2 is on a lower firmware version, you may still insert your existing 2x2TB disks in it then just manually upload the latest firmware v5.3.11.

It is not possible that you update the firmware of a Duo v2 without drives in it.

How do you know the network card is defective?

You would just need a spare disk in the other duo v2 to upgrade the firmware.

There is one other possible option, Netgear has a scheme where, if you buy a new readynas, they will help you to migrate your data. There may be a fee for the migration procedure.

You really should keep backups of your data.

I don’t get link on the switch and leds on the card are dark.
Netgears Raidar program can’t find it and it doesn’t help connecting it direct to my laptop.
So I think the network card is dead, I had a power surge after a thunder storm, my DSL router also died….
Yea, learned the hard way that backup is smart ;-)
I ‘have a spare disk, so I try to update the Duo with this first

Ok, I think you're right, it sounds dead.
I don't think the spare disk factory will achieve anything.
Did you consider my suggestion about a new readynas, I think this would be more sensible than getting another duo v2 which will have no warranty