This may sound silly, but I do not mean it to be silly as an answer.
I have found, over the years, especially with Compaq and HP computers, that when you plug the speaker plugs into the back of the computer, green into green, and pink into pink, there is no sound. But if you reverse them, such that you now have green into pink, and pink into green, you will have sound.
It does not happen every ime, but more times than I thought possible.
Otherwise, take the plugs from the rear of the computer and, if you have outlet jacks on the front of the computer, plug them in there, and see if you can get sound that way.
The saying goes, "It might not help, but it couldn't hurt!"
Answers & Comments
This may sound silly, but I do not mean it to be silly as an answer.
I have found, over the years, especially with Compaq and HP computers, that when you plug the speaker plugs into the back of the computer, green into green, and pink into pink, there is no sound. But if you reverse them, such that you now have green into pink, and pink into green, you will have sound.
It does not happen every ime, but more times than I thought possible.
Otherwise, take the plugs from the rear of the computer and, if you have outlet jacks on the front of the computer, plug them in there, and see if you can get sound that way.
The saying goes, "It might not help, but it couldn't hurt!"
Good luck!
-a.