[DDJ-400] - Low volume coming out on left deck but only through speakers, headphones audio is fine?

Hello all,

I bought a used DDJ-400 with this issue.  I basically only practice in headphones so it's not a huge issue, however it would be nice to fix this.  My feeling is that this issue is to do with the output sockets, since the audio is fine in the headphones.  I would usually just replace the PCB in this scenario but upon doing some research it seems the master output sockets are soldered to the main PCB and to replace this would be very expensive, HOWEVER, since I got a great deal on this unit, I would be willing to try solder a new one on myself.  So my question is what is the individual part called, is it easy enough to solder, and where can I buy it, without buying a whole new flipping main PCB?