I sold a CAL Aria Tube CD player and buyer claims a burning smell

Thank you very much for your honest and detaild answer, as well as for your advise. Yes, it was through Ebay/Paypal and I did specify the unit was not working, I just can't believe how some people would flagrantly lie and rig the system. I was ready to fight it because I believe in justice and fairness, and this buyer really is a crook, but after reading your answer I may just follow your suggestion. It's very frustrating though.
Thank you very very much again! A  

Watch out for them trying to hang on to the unit *and* get a refund.

Wow, I guess I am too honest or naive for this kind of things. Thanks though! 

I just can’t believe how some people would flagrantly lie and rig the system.

Believe it. There are lots of these people out there and they will do all kinds of things to cheat you out of money and/or goods. The advice above about getting your player back and issuing a refund is solid.

Try to learn as much as you can about who you sell to or buy from before you ship or pay, but even then there’s no guarantee that the transaction will go well. Most of the time you will deal with honest people, but there are many dishonest people on the internet.