I had forgotten about this old post.
I ended up replacing the RX-V4600 with a RX-A3040 and knock on wood I've had no issues whatsoever since. Another unit (RX-A2700) also suffered a HDMI board failure but that was due to the ham-handed handling by some carpet installers. I ended up replacing that with a RX-A2000 and that unit is still stepping lively, as well as the other 2 units (RX-A2040, RX-A3000).
