From: sennheiser.ca
To: "Jessica Murray" <death.to.koalas@gmail.com>
The HD 440 II was designed to be user serviceable. This is no longer true with our products, save for the really high end stuff. This is why I mentioned rehabilitation of the old, rather than buying new.
The cable will come out without destroying anything. Wiggle the boot while firmly pulling downward on it. It's been in there a long time, it'll be stubborn. Observe polarity! Letter faces out.
The cable is steel on your model. Big on strength, but tough to solder. If it's not completely trashed, you can put a new plug on. Your call on whether it's worth it.
This model was one of the first to come from the Tullamore factory. They make almost all of Sennheiser's European product nowadays. A few(Uber-expensive) models come from Germany, while the buds and streetwear are out of China.
If your problem is intermittent operation, you can reverse the cable and see if the problem switches sides. If it doesn't, the capsule is trashed, and there's nothing to be done about it. Those parts are long out of production. (One of our techs still uses a pair of these, just to underscore how durable they are)
069427 is the number of the cable, just FYI.