I have a Windows 7 laptop, a Toshiba Satellite Pro C650 (Conexant HD audio - don't know the exact chipset). I've just put it back into service for the kids to watch movies on after several months in storage.
Intermittently, the sound just dies. This can be after a few minutes, or as little as a few seconds. If I bring up the mixer, the sound level meter still shows that there is a sound signal there from whatever sources are outputting, as well as a signal in the main volume meter. There's just no sound coming out of the speakers.
I first figured out that putting the computer to sleep and waking it temporarily fixed it. The audio source didn't need to be shut down for this. I could leave, say, a YouTube video playing when I put it to sleep, and when I woke it up, the video would continue playing, but the sound would have returned.
I've since discovered that simply adjusting the volume, either up or down, in the Windows mixer will also bring the sound back. This really points to a software problem to me, so that's the assumption that I'm working with.
I've tried updating the Intel chipset drivers, and the audio driver. Both of these installed properly with no errors, actually updated the drivers in the device manager, and no errors show on their respective devices. Neither update has fixed the problem, though. I've updated Windows with all the missing updates from its time in storage, which made no difference.
I don't know if it was doing this before it was stored, or not, as it wasn't me that was using it, but I didn't hear anything from the user about audio problems, so I'm assuming (I know....never trust the user) that it didn't.
I've also run sfc (no problems found) and sigverif (no unsigned drivers found).
Both Windows Audio and Windows Audio Endpoint Builder services are running without problems, and no errors at all show up in the Windows event log.
I've updated the BIOS to the latest version from Toshiba's website, again with no effect.
I've backed it up, then done a factory restore to the original Toshiba configuration, and it seems like it might be lasting longer on average now, but it still drops sound after a while, and it's still brought back immediately simply by adjusting the volume in the Windows mixer.
Incidentally, it has to be the main volume that's adjusted, not the individual channel/sound source volume.
I'm still thinking it seems like a software problem, because I don't see how adjusting the volume would somehow reset the hardware to make it work again, but I also don't see how a reinstall wouldn't fix the software problem, if it was that. Unless, of course, it's a problem with Toshiba's implementation of the driver, and I haven't tried a non-Toshiba one, yet.
Things I haven't done yet, but plan to before throwing in the towel:
Audio driver from somewhere other than Toshiba's site.
Anything (well...not anything) you guys suggest.
Does anybody have any ideas to check that I haven't listed? I'm sure somebody must have run across something similar, but I'm also sure that it's a pretty rare problem.