I seem to be having some issues with my speakers randomly "not working" for lack of a better term. Most of the time they will work for about 3-4 hours. Then anywhere from an hour to maybe 3 hours they just wont play any sound while on the PC input, but I CAN play the radio through it. It is an old home theater sound system that i hooked up to the back of my PC with an optical cable. I don't have a sound card I have tried the usual things such as un-plugging it, making sure it is selected as the sound output in the control panel, and rebooting my computer.
As I said earlier I don't have a sound card, maybe that would help?
First order of business is to figure out exactly where the problem is. Next time it happens, do the following:
1. Try connecting the stereo through the 1/8" jack output of the computer instead of the optical cable.
2. Try a different optical output device with the stereo (like an Xbox).
3. Try a pair of headphones or other speakers with the computer.
You need to figure out whether it is software or hardware, and if it's hardware if it's a problem with the optical output or the sound chip in general.
You need to use what's called the "half-split method"; in this case one half is your sound system and one half is your PC.
You need to prove it's either the PC or the sound system, then once you've done that you continue troubleshooting.
So your first step is something like this:
1) replace the SOUND SYSTEM with something else (headphones), or
2) replace the PC with something else (different PC)
There's also the optical cable to swap as well.
*Note that this troubleshooting has to follow the same path (optical). Sticking headphones into the 3.5mm output would only prove anything if the main problem is the main audio chip or its software is having issues. It doesn't prove anything if it's specifically related to the Optical audio and you don't connect to that output.