Need help with ebay buyer

ok so i had sold something to ebay buyer
i had tested the product before listing and tested before shipping it out
it worked fine and now he is saying it doesnt work
i used fedex to ship
what do i do about this please help

I would have the buyer send it back to you at their expense & refund the money. Then, I'd relist it & block the buyer from ever bidding on your items again. Saves you the hassle of dealing with idiots!

I agree with the above post. If you want to avoid negative feedback I would just politely tell them you would be more than happy to give them a refund if they send it back to you. I have found that lots of times buyers are too lazy to send it back and they end up just keeping it. If they do send it back then just refund the money and re-list it again.