Same issue surfaced on my unit within the last two weeks. Contacted Onkyo several days ago about the problem before ever seeing this forum. I did tell them that there were many complaints about the issue online in the U.S. as well as the UK. They took my model and serial numbers along with purchase info, and after placing me on hold briefly, advised me that they would send me box and packing material for return and repair at no charge.
The unit is the first and newest of three Onkyo AV receivers I own, to present a problem. The other two are still in service with no issues. I applaud and thank Onkyo for taking responsibility beyond the traditional warranty period when they know there was a defective component. Corporate responsibility is a scarce commodity in this day and age. Great to see that some companies value their reputation and have a desire to maintain their existing customer base.