I bought it new. I did not realise that I connected it to the wrong PSU before I tried to put it back into the box - it was much too big.
As I said: me=idiot, in this case.
Spend the evening with doing image and data backup wikth a WD MyPassport SE, 1 TB. I think I will have two of these with 1TB each, instead of one drfive with 2 TB. I am safer that way - in case I ruin another hardware item.