[sdiy] MC-202 clock/sync probs (re: broken mc-202)

[Jason Proctor]

GregM fixed some sync problems on my 202. dead or dying transistors 
on the sync board can cause all kinds of problems.


>Most likely a bad slide pot. Try replacing it. While we're talking 
>about MC-202 probs I've got a couple here with clock/sync issues -
>
>MC-202 #1. Seq won't start from internal or external sync. Also on 
>internal sync with no DIN cables connected the tempo always reads 0 
>and the tempo dot in the LCD doesn't blink indicating the internal 
>clock is dead. If I connect a 606 to the Sync In the tempo dot does 
>start blinking and corresponds to the 606 tempo but staring the seq 
>on the 606 still won't start the 202.
>
>MC-202 #2. Seq starts/stops only with external sync. On internal 
>sync am getting a clock it seems (Tempo can be adjusted and tempo 
>dot in LCD is blinking to the rate) but cannot start or stop the 
>sequencer. The start/stop button works so that's not it.
>
>Any ideas?
>
>Thanks
>Doug
>
>--- On Wed, 7/8/09, Danjel van Tijn <danjel at gmail.com> wrote:
>>  Just picked up a broken mc-202 with a
>>  (possibly) minor issue.
>>
>>  There seems to be a problem with the releases phase of the
>>  envelope.
>>  When the R is at 0 everything is fine but when R is at any
>>  value
>>  greater than zero it sustains infinitely.
>>  I am guessing that the R slider forms part of RC timing
>>  circuit for
>>  the ADSR so that maybe if it is broken (ie. the
>>  potentiometer is an
>>  open circuit) then at any value other than zero (where it
>>  is shorted
>>  out) it never a release/discharges.
>>
>>  Any clues?
>>
>>
>>  cheers,
>>  Danjel
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