So I took apart my HD 650 headphones (easy but be gentle if you need to take yours apart) and noticed on the clear diaphragms (about 1.5" in diameter") that it says HD-580.  I bought them used.  They've always sounded marvelous but I never compared them to other Sennheisers in this price range.  Above the HD-580 it says:
14 06 07 or 16 0G 07.  Below that it says MINI SYS with the HD-580 on the 3rd line.  Wondering if these diaphragms have been switched.
 
The reason I did this was one channel was intermittent.  As I moved the wire in and out I could hear that channel but then it was gone.  Very hard to determine what position worked.  I tried the other 2 pronged end and that is reliable so its definitely just one end.  I have no idea what to do.  They look identical.  The plugs are cheap.  Hopefully not too difficult to solder.  Is this a common problem with Seinnheisers with these kind of connections?

http://www.headfonia.com/the-sennheiser-trio-hd580-hd600-hd650/
http://www.innerfidelity.com/content/very-important-sennheiser-hd-580-hd-600-and-hd-650

Was that supposed to be a yes or no?  Didn't see any mention of 580 diaphragms used in the 650 in either article.  Did I miss something?