The audio cables on technics can go bad pretty easy.... I've had to get mine replaced because the audio would simply cut out. If you know how to solder and all that jazz its not too hard... gotta take off the entire bottom and then theres a 2 screw bracket that holds the cables down... pull that off and you'll see where the cables are attached.

Go get yourself some really thick paired rca cables... 10-12' and cut em right in half.... do both of your decks :)