Onboard audio failing

Oh, thy wise MG's, can you be of help?

I've build my own PC a few years ago and it was running just wonderfully. Handling the newer games (for me new anyway ) brilliantly, same for the sound - until a few weeks ago.
The sound disappears from stereo to mono at random.. Quite annoying when you're ready to rock out :dood and the sound goes to half of what it used to be >.<

The MoBo I use, is an ASRock 960GM-VGS3 FX . Am very happy with it, aside of the onboard audio that begins to fail for unknown reasons.
Nothing else is affected, just the darn sound has gone cuckoo. Tried a few different speaker sets, but to no avail - issue remains (could've been a faulty wire or jack).

Does anyone have tips / suggestions of what I can try to resolve this issue?
Or am I better off, looking for a separate sound card and turn off the onboard?

If a separate sound card would be advised, would an old card, like the CT4170, help me out until I find a younger card I can afford?

Thank you in advance :wine

 

Things I have seen cause this, usually I get it fixed, but I never find a smoking gun. I assume you have proven the speakers work on another system. Try what you like:

1) driver corruption, try newer and older drivers and be sure the previous one is gone
2) If it happens only in games there may be no cure. TERA and a few others changed to "dynamic" sound so the distance you are from the noise and the side it's on is more "realistic". On many systems this means no sound or too loud. Change game settings. I wound up disabling stereo.
3) dirty connections, bad ground on speaker power
4) bad power supply, usually only one leg going south so the computer runs fine except the sound (nothing else worked so I just got lucky or stupid and swapped the PSU)

 

Apologies for late reply, lot on my mind these days.
Thank you, for your reply.

It only happens when using audio players, like WMP or WinAmp (I don't run any others, 2 is sufficient ).
Tried different speaker sets, as stated, problem remains.

Drivers are up to date, and older driver has the same problem.

 

Have you tried the control panel speaker tests?
Does the control panel also change to mono or does it stay at your setting?
Also check device manager to see if Windows is confused there.