to be honest man, i really dont know the answer to that. i have never had a problem with any of my refurb purchases, so i dont know the process to get one fixed. if you have already spoke with denon, and they are gonna try and fix it, i asume that they are taking responsibilty for the unit not working, and they are not leaving it up to you and the online store you bought it from. i would think if denon is taking responsibility to fix it, then they would take responsibility to replace it if it cant be fixed.. i really aint sure, i am just guessing.. i would contact denon directly and find out what options you have, and what they will do for you.
good luck with it, and keep us informed on your process.
EXCUSE ME, ARE YOU THE SINGING BUSH??