Craigslist transaction went south...

Yes give him his money back. You don't need this hassle in your life. 

September 15th 2017, 7:41:14 pm 
Hey you bought the receiver on September 4th.
It has been more than 10 days. Now you are
telling me that there is no sound output. Go
ahead and take a legal action. I would be glad
to face it

It sounds as if you are looking forward to some legal action.

Beware Craigslist, many scams. One scam is to replace a non-working unit with a properly working unit.

Say I own a Abracadabra Model ABC123, and it has stopped working. Then I scan the ads looking for another Abracadabra Model ABC123.
When I find one, I buy it. Then try to con my old one off as a broken one, and get my money back. Now my unit is working again, and it didn't cost me anything.

I've never done this, but I have heard this story many times, usually from Craigslist. Seller Beware.

As others have suggested, give the money back and record the transaction. Chalk it off to lesson learned.

I have sold about 10 electronics on Craigslist and each time I’ve insisted on demoing the components. A bit of hassle to do all that but it’s well worth it. I keep this bad boy in my vehicle for demonstration,

"Fospower 150w 12V DC to 110V AC Portable Automobile Car Power Inverter with 2 USB Charging Ports"

Also do not invite strangers to your home, always pick a public place to conduct Craigslist transactions.

Good luck!

@jmcgrogan2 ~ good point. Thanks for sharing.