Why is there no sound in my MacBook Air?

Hello,

I bought a Macbook Air original (a1237), and there is no sound coming out. Not from the internal speakers nor the headphone jack. It shows that an audio device is available, and that nothing is muted.

Here is a screenshot of my settings (does everything look normal?) https://onedrive.live.com/redir?resid=14...

I found that the sound cable might be broken, but then it wouldn't register an audio device, I also tried, and disconnected it to be sure about it. I have also tried resetting the SMC, and PRAM, but it didn't help.

Do I need to replace something (audio board for example) or might it just be a software problem?

The previous owner said that he tried to change the hard drive, so I thought that maybe headphones switch has broken, and that's why I didn't get any sound in my integrated speakers, and there is no sound in the headphones because the wire going from audio device to headphone jack is broken. Is this scenario also possible?

Thank you for your time reading this :D