I would demand 100% return. No way in hell I would send a newly purchased Denon for repair.
Like I've been telling people, I hate refurbished. No way in hell I would ever buy refurbished. But no one wants to listen to me until crap happens to them firsthand.
I've bought like 4 bad refurbished and the seller eCost & Dakmart wanted me to ship to Denon for repair. No way. I demanded full refund and got it each time.
When I got a defective refurbished AVP-A1HDCI, they really wanted to refuse return. But I gave them hell. Told them I would tell everyone n all the forums about their bad business. Said I would DISPUTE MY CREDIT CARD.
That's the key right there. Tell them you will dispute w/ your CC company and raise hell if they don't accept return.
And then don't ever buy refurbished from anyone.