[sdiy] Pratt-Reed Mechanisms

[The Old Crow]

  (key not triggering)

  It is possible the gold-plate has worn off the contact edge of the
J-wire, the buss bar, or both.  You can get a gold-contact restorative
(usually sold in little 3ml jars or a 'pen'), but these can be pricey.

  Unless you have a very good reason to dismount the J-wire PC board from
the keyframe, I would not do it.  I took apart the key action for a
Prophet-5 a while back to resolder about 30 J-wires, and while nothing got
broken, I can say it is a very delicate affair.  See:

http://www.oldcrows.net/~oldcrow/synth/sci/Image003.jpg

  All of those little plastic PCB standoffs have to be carefully extracted
from the steel frame without jarring the PCB assembly.  Note that all of
the keys were removed to fit new bushings.  This also has to be don to
gain access to the mounting hols of the standoffs.

Crow

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