External speaker issue

Hi all, I have an issue with a macbook pro, the osx is current.

when I plug in my external speakers, into the port the speaker icon is greyed out.

i have looked under the settings and it says digital out. I am unable to to change anything as there is no drop box.

there is also no red light coming from the port.

I am at a loss to think what else it could be.

Any ideas?

 

Thanks. I have just tried this, unfortunately I still get the same issue.

I have also reset the pRAM too, but nothing. I Know it's not the speakers as they work fine in my PC, I'm guessing it could be the logic board in the mac.