I bought a "for parts" DD2 on eBay. Looks fine, tape speed is fine, but when I first switched it on, only the right channel worked. I lubricated the volume pot with Sonax and now the left channel plays but the volume pot does not vary the left channel volume. It stays at the same volume. The right channel still goes up and down fine. Can these be pots be repaired or does anybody know of or is selling a replacement kit for these volume controls? Which Walkman's are these volume pots common to? I might have to buy a scrap machine to get a working one out of.