Go to the Resolution Centre at the bottom of this page.
They will tell you to contact the seller.
He may tell you to return the broken item. Ask if he will accept a photo. He may say yes.
He is allowed to ask for return before refund.
Do NOT accept a replacement. There is no reason to believe it would be any better than the original item.
If all that goes smoothly, you can use the refund to buy another machine from the seller.
If he refuses, go to the Resolution Centre again.
Open an Item Not As Described Dispute.
If the seller does not refund you (and again, you may be required to return the item WITH CONFIRMATION OF DELIVERY) Paypal/eBay will and go after him for their money.
Neither of you will be able to leave feedback.