HDMI Sound randomly not working - test in settings gets it working?

[Livin]

I have started having an issue over the past week (config/drivers/etc not changed in months) where sound will randomly not be output by HDMI.

System config/specs...
Win7 SP1 all patches, nearly a stock install... only running WMC and XBMC.
Only 3rd part stuff installed are SpeedFan an ATI drivers. (problem occurs if Speedfan is running, or not)
system runs 16 hrs per day, auto shutdown at night.
Dell Optiplex, 6GB RAM + Core2Duo E7400, SSD - no swap file
HDMI is the default, and only sound device enabled (disabled all others in OS)

History... was working perfectly for over 2 years. One Win7 rebuild in that time. Updated video card once and drivers occasionally.


Symptom...
Approx half the time when I start up WMC or XBMC sound output via HDMI does not work. The other half of the time it works fine.
-- to get it working I can open Sound CPL and run "test". Sound will play through HDMI and all is fine usually the rest of the day, but sometimes it has the problem again if I don't use the system for several hours.
-- it never faults (stops working) while in use... only on initial XBMC or WMC startup... again system is always running hours before I start the apps.



Any ideas?

 

[Maguscreed]

This sounds like a problem with the video driver pack (also includes hdmi audio driver)
I would completely remove what you have now then download and reinstall the latest fresh again.
It could just be a glitch in the matrix so to speak.