Headphone port going bad?

Hi all,

I'll cut to the chase; I'm using a late 2011 MacBookPro, the left channel of my buit-in headphone amplifier is dying. Whenever I plug a set of headphones in for normal lisening, like iTunes, the right channel is much louder than the left. The problem gets worse at higher volumes as the channel ballance problem becomes more noticable. I am sure it isn't a problem with my headphones, they sound great when powered by an iPhone or a reciever. I only have this problem with my laptop.

Anyone having a similar issue? Heard about something similar?

When I use an external audio interface there is no issue, but I can't afford to carry that with me at all times. Also, I just had my logic board replaced so I am wondering if the 2 problems may be related. Thanks for the help!

Cheers,

-Nick