I would bypass the Onkyo customer service. I bought an Onkyo in 2008 and it immediately popped one of the channels.
Perhaps I could have contacted the dealer, Abt, but I destroyed the shipping carton and the actual box. After finding out that Onkyo did not sell spare boxes, I went the authorized service route, even though they were 100 miles from my home. They have direct access to Onkyo, shielding you from frustration. They repaired it under warranty with no questions asked other than a copy of the sales receipt.