I have a somewhat odd problem. I was using onboard graphics, and my sound was working very well. Then I added a graphics card, and when I connect my headphones now, I hear a bunch of strange beeps and sounds (think I can hear the CPU fan for instance), but no sound. The beeps and noises are correlated with what I do on the computer as well. For instance, if I minimise something, I hear a dull bffffrrr sound. Trying to play music results in a highly penetrating high pitched beep. After removing the graphics card, the problem remained. The same holds for both front and rear outputs.
Windows does recognise that I insert headphones. Also, it is under the impression that I am receiving sound (the green volume indicator in sound settings). Unfortunately, no proper sounds get through. So it is not disabled, but it's not working properly either.
Does anybody know the cause of this problem?
Edit: I tested uninstalling the graphics card drivers. Then uninstalling and reinstalling the audio drivers (tested both windows update drivers, and manufacturer drivers). I also restore the image from my system of 1 week back (before the problem occurred), without having the graphics card inside my system, and it did not help. This leads me to believe it is a hardware issue. Additionally I tried grounding the USB port (to the radiator, to avoid a ground loop), this did not make any difference. Additionally I tried psycogeek's suggestions, disabling all other audio devices, and reducing all other volumes to zero. I found out that part of the strange sounds I hear are independent of the volume. For instance, I can hear myself typing through my headphones right now, even though the volume is set to zero. To be sure that it isn't a software issue, I booted the computer from Ubuntu Linux (usb stick), and this gave me the exact same result. Additionally I tried grounding the case to the radiator, this did not work either. From this I can conclude that it must be a hardware issue. I wonder if there's anything left but replace my motherboard.
The video card was placed after grounding myself to the radiator. Additionally, the ground was still connected to the computer, but the PSU was of during placement.
Any further suggestions are of course very welcome. Also, I'd be interested to know how adding graphics card could have caused this issue, and how I can prevent it in the future.
My computer's main specs: i5-4690; Gigabyte Z97x-UD3H-BK (motherboard); Nvidia Quadro 600 (graphics card); Windows 7
PS. in the end, I had the manufacturer repair my motherboard, this did indeed solve the problem. Because I was afraid it would happen again, I discarded the graphics card and got a different one.edit: