No Device Connected error

[Huskerfan]

Got a new/refurbished 6900 through Verizon. It has radio 3.37 and the coke screen says:

SPL-2.01.0000
CPLD-3

This is the way it came from Verizon.

I tried to unlock with Coke 2.31 and I get a pop up that says No Device Connected --Would you like to try copying again? If I hit yes the same error pops up. This also happened on my last 6900 and that's part of the reason Verizon sent me a warranty phone.

I thought it was a pc error so I've now tried it on 4 different pc's and I get the same result from each.

Can anyone offer any advice? I 'd appreciate it.