Expansion from 500gb to 2tb became a nightmare (Readynas 110

Hi,

I got an old ReadyNas 1100 that had 4x500GB drives from start. One gave up so there were 3. I thought I should by some upgrade disks and went ahead and bought 2x2TB. Now begin the dream. I just inserted on of them and let it sync. It worked great. And I had read up on Xraid so I knew that installing one 2TB drive would let that one became a mirror and not actually adding any capacity to the already ~1,4TB. Fine. Then i inserted the last 2TB disk and let that one sync. Also mirroring. So still 1,4TB data storage and fully redundant. It was not fine. I wanted more storage, and since it is used for a backup backup I wanted at least 2TB of storage capacity.

So I did a factory reset and change of disk volume and raid. Enter the nightmare.

At first I'd said initializing in RAIDar, but then the NAS went away.
For 24h I let it on. Nothing but a slow blue blinking. Finally I powered it down by the power switch at the back. Tried to restart the factory reset a few times. Ni change. So i though it was one of the drives. Tried them in different order and finally found one that did boot - the old 500gb drives only.

So I thought, hey let's just redo everything from before with the start of 2x500 GB and than add 2x2TB.

It all went fine at the start but then when I inserted the 2TB drives I got these messages that they could not initialize.
Rebooted, tried factory reset, firmware upgrade (4.1.15-TB2),os reinstall and so on. Journal on, power down off, no snapshot. So on.

No the would help my poor new 2TB drives.

So I thought that I might connect them to a computer and do a check and format. No disks found.

So what have I done? Wrong? What? I mean, my drives where fine. Now they're dead. Why did my first factory reset hang, and could I somehow rescue my drives?

Cheers,
Daniel