I had problems with my computer's audio when I first got it and updated the Nvidia card drivers. The sound was fine as long as I didn't take the volume higher than 40.
Of course, it could be a physical problem too. You tried different speakers on that computer, but did you try those speakers on a different computer or device to see if they actually do work? If they work on a different device, then the problem may be where you plug in the speakers on your computer. Plug in some headphones into the headphones plug and see if those work. If they don't, then it could be the whole card needs replaced.
I'm no expert and it could be something else entirely, but this should give you a place to start. Let us know what you find out.
My sound quit working. I have no idea why. It worked and then it didn't work. I have checked the volume control and it is not on mute. Everything is plugged in. I also hooked up a different set of speakers and they would not work either. Any suggestions Please?