Compatibility of discs running in failed ReadyNas RN104 with new ReadyNas RN214

Thanks for the helpful reply.

Short version: it would not boot discless at all and behave the same way; it did boot once when I put in a single spare disc BUT only with the recovery USB flash inserted; once that flash is removed it reverts to the same behavior as with the four orginal discs or with no disc. Then, after that initial successful recovery USB aided bootup, the system reverted to the same behavior with the new disc as it had with the original four discs.

Longer version:

(A) Discless test results: I removed the discs and tried to start discless. It immediately goes to the "boot from USB" status with the power and backup lights alternately strobing, and never gets anywhere the normal booting screen, much less a screen that says "No discs." That occurs whether or not there is actually a USB in the drive; then, if there is the recovery USB in the drive it runs that sequence and shuts down, or if not, proceeds to the "boot from USB failed!" message. If I remove the USB from the shut down drive and try to restart as normal, it still goes immediately to the "boot from USB" screen/flashing. If I let it try to boot without the USB in, and get the "boot from USB failed!" message, then the only way to shut down the chassis is to unplug the power cord, as it is otherwise unresponsive to the power button. Then, once the power cord is plugged in again (even after waiting ten minutes) it goes immediately to the "boot from USB" status and results in the same as with the discs in, i.e. "Boot from USB failed!" if there is no USB drive inserted, or running the recovery sequence and shutting down if the recovery USB was inserted.

(B) New disc inserted results: when inserting the new disc it would not boot without the USB recovery also inserted, giving the "boot from USB failed!" message and freezing there. However, after shutting down by pulling the plug, inserting the recovery USB, and then restarting, it then saw the new disc (not previously RAID/OS6 formatted) and started up normally (though needing extra time to format the disc). RAIDar saw it with no special messages other than to note that I now had one, but not four, discs in the bays. I then shut down per normal, and everything seemed normal. I removed the USB recovery drive and restarted as normal. This time it reverted immediately back to the old behavior as described in (A) above, and again I cannot get it to boot up at all, and cannot connect to RAIDar.

Thanks again for your time. I've gone ahead and ordered a new RN214 since having my system down too long is worse than the $389 bill. My chief concern is thus being sure I can simply swap in the four discs from the RN104 into the new RN214 without having the new RN214 see them as something that needs to be newly formatted and thus wiped completely clean. 

I do have an older NAS unit that is used as my failsafe backup (so in answer to Stephen, "yes, my backup is backed up, though it is a huge pain to transfer data from that older unit, lost time I would like to avoid"). It would still not be a terrible outcome if you think this RN104 chassis can be resurrected to be reliable, at which point I will let it become my triple failsafe. Any thoughts you have along those lines would be most welcome, and again, thanks for your time and courtesy.