I sold an expensive item on ebay this week, an surround sound amp.
Send the item 24hour parcel force. Buyer saying it is faulty, not working, but it was absolutely working when we sent it, we had used it ourselves and it worked fine for us.
DH said the fault he is describing is an electronic fault, so would not have been caused by being damaged in the post. He said it is damage caused by basically 'being blown'.
What is the normal process now? We have explained it was working fine when we sent it, and asked him how he wishes to proceed, but do we have to refund him? ie, what if he blew it his end trying it out?