Hey

I've had my Pioneer DJM600 for about 3 years now and i bought it used. It's still doing the job pretty well, but i'm having a problem with the headphone mixing knob (located above the headphone level on the bottom left corner of the mixer)
this knob is supposed to crossfade between the master output from the mixer and the cueed channel. (if anyone is confused as to what i'm talking about, i can post up a picture to clarify)

Now, say i have the master level cued to go to the headphones and say channel 1 as the new channel i'm cueing up to mix into. when I have the knob turned all the way to the left so that only the cued channel is audible, i will hear channel 1 fine. but if i turn the mixing knob slightly up to the right just a pinch to start mixing in the master channel to the headphones, i will get some distortion and the master channel will come on very loud as if, the mixing knob is turned up all the way to the right, where the master should be loudest. then if i turn the knob slightly more to the right, the levels will go back to about what they should be. its just at this one point, right above the strictly cued channel point, where everything gets distorted.

i hope i'm explaining this well enough so everyone can understand what im talking about

does anyone know how to fix this? i'm guessing some of the wires are going bad or something. i'd rather not take the mixer into the shop. i'd like to fix it if it is plausable.

thanks