524X Can't factory reset, help

yes I'm sure I did factory reset.

I did a lot of different things trying to get this working so its a little murky now what all I have tried, but I have tried factory reset numerous times including with all three disks and with only two disks.

I first did it with 3 disks inside after having done a boot menu disk test to discover disk#4 had errors and I removed it..

but it failed to reset with the remaining three drives, gave me an error message on the front of the readynas and in raidar a message about corrupt root.  I did googling and found out this is normal, readynasOS is designed to not overwrite it if you have one or more other volumes, it will not erase the new third one if it thinks there might be some old valid data on it....ie...detects a root or detects certain partition or something like that.

I tried to also factory reset only with disk#3 and it also failed.

At some point I did it with only first two disks and that worked.    

when I try to put disk 3 back in, it complains that in order to use it I must remove the first two "inactive" disks.  I don't want to use it, I want to erase it.  but readynas will not erase it or reset it.

I have already tried numerous times to DESTROY all known volumes and FORMAT each of the disks... but ultimately this third disk keeps coming back with a status that there is an old 16TB volume associated with it and does not want to be reset or erased.