[sdiy] How to repair an moog organ?

[Dave Magnuson]

At 12:15 PM 11/2/01 +0100, you wrote:
>Hi,
>
>I am about to repair an Moog Cordovox electronic organ, synth.
>It is a university project and I have a good background in electronic
theory but I have never really repaired somerthing.
>
>So how would I go about it?
>
>The organ seems to be in a bad state and wasn't used for years,it is very
dirty and so are all sliders and buttons.
>
>Shall I power it on and see whats wrong with it or shall i do some
measurements first?
>
>I also don't have the circuit diagrams jet but I hope I will find a copy
soon. (Hope)
>
>Any help from experienced service people would be appreciated.
>
>Thanks a lot.
>


Personally, the first thing I would do is disconnect the powersupply from
the main synth boards (if possible).  Otherwise an over-voltage might cook
a bunch of other stuff downstream.  I *ALWAYS* try to test the powersupply
of unknown gear first.  This is especially important if there are obsolete
components in there.

When you power it up, make sure the power supply is stable...  Check that
it's regulating properly, and look at the output on a scope and see if
there's a lot of ripple (bad caps).  Remember that some regulators need a
resistive load to work properly...  

If the power supply is ok, start reconnecting various boards and check to
see if they're working. 

Dave Magnuson


Resonant Frequency:
resfreq at hoohahrecords.com
http://www.hoohahrecords.com/resfreq/index.html