Sick vortex

[malhomme <malhomme@infobiogen.fr>]

Oh, I know pretty well the problem, since when my brand new vortex, at
the time flew from US to France, it arrived with the same problem.

It is the encoder rotary pot in itself that is guilty. It becomes
intermittent, and the factory preset are difficult to get, and
especially to keep. The user one (if you dial through footswitches) are
posing no problems. It is just the selection of programms through the
encoder that is nuts.
You "just" have to change the encoder. An iron, a little solder stuff,
or ship it back to lexicon, if it still is cevired with warranty.
Otherwise, try to find such an encoder. Those are the same used on
reflex/alex/ maybe even jamdudes. 
Their are knowm to be sometimes faulty. Not often, just, it felt on us.
That's life....

Olivier Malhomme