How can you be sure that re-cabling will fix the problem?  You're sure it has nothing to do with something in the ear cup?

I'm in Canada - about right above MN.  I tried messing around with the wire, no dice.  The weird thing is, is it just fades out like something just can't take it anymore.

I shouldn't say doesn't work entirely, but if I don't use the headphones for a good period of time (say a day or two) the left channel starts to work again for about 30 minutes or so, then it just completely stops working.  Sometimes when I fiddle with my amp and turn it up higher I can bring...