My HTPC recently started producing glitchy audio. It's connected to my processor via an optical cable.
This seems to happen with all digital audio; DVR-MS, AVI/WMV/MKV, MP3, WAV & DVD.
It is possible to 'loopback' or otherwise trap the digital output being sent to my processor so that I can analyse it somehow? I used to work for an audio company and know first hand how difficult these kind of things can be to trace, but my experience in the PC domain is fairly limited and I have no access to a spectrum analyser nowadays.
Edit: The audio eventually failed completely. A system restore didn't rectify it, so I reinstalled Windows and applied all updated drivers - still no go. I then mucked about with various device settings and weirdly somehow it started working, firstly via HDMI then via toslink too. It still occasionally glitches though
I think the onboard audio is gubbed :(