Only left side of headphone/speaker is working

[Psittacus]

Hey,

So last month I bought a 13" rMBP (now running Yosemite 10.10.1) and yesterday while trying out a subwoofer I got, it started playing out only the left side of headphones or speakers. I know it's not the headphones cause I've tried it on other devices and no matter what is plugged in to it, on only comes out left side.
From the forums I've read it doesn't seem to be a sound card or the logic board, otherwise it wouldn't be working at all. The most logical explanation is that the connection inside the jack is messed up, but the mac is only 1 month old.
I've checked the setup on sound preferences and Audio MIDI Setup and both seem fine.

Does anyone know how to fix this without taking it to warranty service?
Thanks.

 

[Psittacus]

Also tried PRAM reset, didn't work.

 

[GP-SE]

did you plug the subwoofer directly into the Laptop? if so then you may have damaged the logic board. Do the internal speakers work fine?

 

[Partron22]

You've actually moved the balance control to left and right?
Sometimes prefs get messed up relative to display, and need rewriting.

What happens when you rotate the headphone jack while listening to music?
A bad connection will often be noticeably intermittent.

What about the Mac's internal speaker(s)? Do you get both left and right from them?

 

[Psittacus]

did you plug the subwoofer directly into the Laptop? if so then you may have damaged the logic board. Do the internal speakers work fine?

No I didn't pluged it directly. Yes, internal speakers work just fine and balanced.

You've actually moved the balance control to left and right?
Sometimes prefs get messed up relative to display, and need rewriting.

What happens when you rotate the headphone jack while listening to music?
A bad connection will often be noticeably intermittent.

What about the Mac's internal speaker(s)? Do you get both left and right from them?

Yes I did, it didn't fixed it.
Internal speakers work just fine and balanced.
I've tried with several headphones, also tried to rotate the headphone jack and right side doesn't give a single noise.

Thank you both for your help.

 

[Pudlo]

Just take it to apple store. It's a new mac so it shouldn't happen but...it can