[sdiy] fixing Alps rotary encoders

[Nils Pipenbrinck]

Hi.

One of my multieffect things uses these alps rotary encoders for data entry.
It doesn't work reliable anymore (works fine in clockwise, but the data
jumps around when turned counterclockwise).

Does anyone has an idea to fix these things? I don't know if they work
optical or mechanical, so I don't want to use contact spray. Blowing some
air through it helped, but the problem came back after two days.

Thanks,
  Nils