I used the link that you provided to get to instructions regarding the boot menu and factory default procedure.
I selected my model from the table of contents list: "Duo/NV/NV+/x6/600" is what I picked.
I turned off the Duo - removed the 2 good drives and installed the bad drive in the disk 1 position.
I depressed and held in the reset switch while I turned the power on... the instructions didn't say how long to hold in the reset switch, so I kept it depressed for probably about 20 - 30 seconds.
4 hours later...
So now, the Duo has been flashing all it's leds (both disk leds, something labled "act" (which looks like a activity led), the "backup" led, and the blue power light. It's been flashing all those leds for about 4 hours.
The instructions say nothing else other than what I wrote above.
I don't know if the Duo is waiting for me to do something or if I'm waiting for it to complete something.
Do you know how long it will take to perform the "Factory Default" process?
Can you tell if I've done something incorrectly?
The blue power light has a steady rhythmic flash. The other four green leds are flashing in unison (all together) and the flash pattern is: 3 long, 3 short, and then back to 3 long flashes. I think it's sending me an "SOS"
Do you have any ideas as to what is happening?
I thought that I'd give it another couple of hours, then power down, take out the bad drive, reinstall the 2 good drives, and make sure that they power up ok. If they're ok, I could remove then again, put in the bad one and try this again.