I've been having an ongoing issue with the audio in some games in my HTPC. The setup is an MSI motherboard with a Realtek sound chip onboard. Connected to that is an Nvidia 550ti, and I use the HDMI port from that to send audio and video to the TV.

In some games (not all) after some time the signal to the TV will completely cut out for a second. When it comes back, I have video but not audio. Quitting the game and restarting it is enough to get the audio back.

I've reinstalled both the newest driver for the Realtek chip as well as reinstalled the HD audio driver for the GPU, but the issue still occurs. I don't know enough about this setup to know if the audio processing is still being done by the Realtek, or if the GPU has something built in for that. Does anyone have any ideas on what could be causing this, and what could fix it?