Hello, recently while using my Onkyo S3400 surround sound the sound would start to fade out and eventually stop completely until I turned off the receiver and turned it back on when it would start the process over again. Now the receiver will not output any sound at all no matter what I do. I have checked all of my connections and tried different settings to no avail. It seemed to happen after using the unit at moderate sound (10-15) on the volume dial and the receiver itself became hot. I'm concerned that it may be a heatsink issue however the unit is less than a year old. What do you think?