Q: Speaker Problems on MBP Late 2011

Hi there,

I am having some problems with the speakers on my mac book pro  15" late 2011.

Problem description:

     - When restarting my computer the speakers crack a few times then go silent, specifically the right speaker.

     - When running, the speaker icon is  not responsive, neither are the speaker keys 

Potential solutions tried:

     - Checked system preferences > sound >no device found for output.

     - Checked to see if a red light is lit in the line-out port. None seen.

     - Reset PRAM, NVRAM. No effect.

     - Ran apple hardware diagnostic tool. No problems found.

I think that a speaker is blown or there is a loose connection. Looking for some advice on diagnosing the problem and a potential fix.

Cheers