When toying with the AVR's settings failed to provide a fix, I went scouring my PC for a solution. Previously, I had gone into Device Manager and attempted to update the audio/video drivers myself just by pressing the "Update Driver" button. Of course, when doing so, it found no updates. I assumed this stuff was supposed to work properly. Apparently not.
So, tonight, I decided to cross-reference my driver's versions to the AMD and Realtek websites. Turns out, to my unknowing, Windows just wasn't finding the newest drivers when using the above method, and my drivers were on the brink of becoming ancient.
So, I downloaded both the ATi Radeon 5xxx Series GPU driver update (since the video card handles the audio thru HDMI, I assumed it could have something to do with it
) and the Realtek Audio driver updates (both the standard sound card driver and the HDMI audio driver) at their respecive websites.
The PC boots after installations are complete, I swap over to HDMI, and viola, constant audio signal. This damned thing finally works as it should, after 8 months of just dealing with it and thinking it was "normal." The GPU drivers were a pain in the ass, as I dealt with numerous hitches, including a BSOD (scared the hell out of me
), but I managed to work it out. The audio drivers were a piece of cake.
I can't believe I didn't think to do this sooner.
Shark007 mentioned drivers, but when Windows told me they were up-to-date, I looked past it. Thanks for the help, guys.