[Babaloo]

My guess is that the magnets in my tech/2 are corroded. But I'm really not sure, since my knowledge on sound equipment/cans/eletronics is really minimal.

I'd like very much to repair and keep them, maybe find parts from a present model that will do the job. here's a couple of pictures of the beast:

 

[ericj]

What you're seeing there looks to me like decomposing foam rubber. The construction of the Tech/2 driver looks very similar to the HV/1, which has a toroidal ferrite magnet embedded in molded plastic.

If i were in your shoes, I'd put an ohm meter across the posts on the back of the driver and make sure the coil is not broken, since you say they are silent.

Even if the magnets were shattered, rusty, and largely demagnetized, they would still make some sound.

Reports of demagnetized headphones are extremely (vanishingly) rare and seem to be limited to WWII era headsets.

My guess is that there is nothing wrong with the magnets, but the voice coils might be broken.

fwiw, if i'm right and the construction is similar to the HV/1, the driver is integral to the baffle, and any attempt to remove the driver from the baffle plate will tear the diaphragm and voice coil from the frame and magnets.

At least, that's what happened to my HV/1-LC.

Edit: oh, and Koss will probably send you new earpads for $5 shipped.