Well,..
I removed a Cessna 300 series RT359 transponder out of my Aerobat, and it was working when removed,( I flew the day before I had the avionics shop install the new one, so I know it was OK), and I had the bi-annual XPDR check done about a year earlier-again no problems.
So I list it on eBay, and my listing clearly stated "as is" due to it being an electronic device....
So, about two weeks later, the buyer emails me and claims the unit was DOA, his current RT359 is OK therefor it must be that the one he bought is bad, and now wants me to respond.
You think he swapped out the cavity tube and now is trying to in effect have his unit fixed for free by swapping parts?
Is this a scam?
Should I offer to have him return it for an exam by my radio shop to see if the cavity tube was switched?
I KNOW the unit was good when I shipped it out.
-Brian