Vintage Synth Repair

Hey Guys,

A friend is having a problem with his RMI 300 Series Electra piano.  
He has helped me a ton with various repair projects, so I am trying 
to dig up some info on this for him.  I was wondering if any of you 
have run into this before...  Here's his email:

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I put a new power cord on the RMI piano (I swear, that's all I did) 
and now it is acting funny.

Symptom: the attack of a note triggers a brief noise burst and 
(worse), the release of a note causes a noise burst, too. When I put 
the Organ Mode ON (which changes the sustain characteristic of notes 
held), the noise is constant (but quieter).

Can't figure how a new power cord would cause this. Of course, it 
probably did not cause it, but it WAS working fine before I chopped 
the old (working, but really frayed) cord off.

I was hoping you might be able to hook me up with a knowledgeable RMI 
amigos on your organ site(s). I don't know anything about the 
envelope controls of these things!

I also need a tuning procedure.

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Thanks in advance for any help you can throw our way!
Jim