how to unblock Kindle/Oasis???
 

HI, I bought a new Oasis private. I called amazon and they told me, even the package wasn't open, the Reader is stolen. So they can't reopen it. my question is. Can I change the Serial number or the Firmware and make it work again? Otherwise, I can't use it and I lost much money:/

Go back to the seller and get your money back. No one here will assist you on getting around Amazon's block.

Bro, if I could, I would! But it was here in germany on "kleinanzeigen" so no chance to find the seller!!!

Are there no buyer protections on eBay Germany?

on ebay yes, but not on ebay kleinanzeigen

kleinanzeigen = Classified Adverts? Maybe not eBay at all. Indeed I've used eBay Germany and it has the same protections as UK and Ireland. On eBay you'd get the money back UNLESS it's described as Blocked/Locked. Such Kindles are advertised as such in volume, so not just stolen ones are blocked. You can't make collections or use them directly with Amazon. You can sideload/USB transfer any mobi or azw that has no DRM.

kleinanzeigen = Classified Adverts this is correct.
Yeah, I saw that I still can "use" it by loading stuff from PC.
I guess I have to go this way. Thank you anyway

This is why it's never a good idea to buy a used Kindle from a source you don't know 100%. Kindles are the only Reader I would never buy from an unknown second hand source.

You won't know if it's blacklisted or not and if it is, there's a very good chance that it's either stolen or found and in either case it's selling stolen goods.

Only once did I run into a registration blocked kindle from a ebay purchase and the seller refunded my money when I returned it. The seller claimed it was part of a bulk purchase from a pawn shop when I reported the problem. The listing did not list it as blocked. I would be leery of buying any Kindle from a pawn shop.

I have had no problems buying Amazon factory refurbished Kindle readers on ebay or those from ebay sellers who do non-Amazon refurbishing of units and have a reasonable number of transactions count with positive feedback. I would not buy a Kindle from a private seller with a no returns listing.