Sorry to comment on an old thread, but you sir are my hero. I had the exact same issue, didn't play it for 2 weeks, powered it up, no sound from speakers but headphones worked. Found this thread via google and tried the Q-tips/alcohol and it solved the problem!
I created an account on this forum just so I could thank you, until I found this thread I was thinking of how much of a hassle it's going to be to pack it and ship it back for repair, but a bunch of Q-tips did it. Thank you again.