[sdiy] Advices for restoring an old Roland SH2

[Chris Juried]

I have seen this issue before as well Richie. The ground trace, to the 1/4" chassis mount connector, is susceptible to excess current and can become an open-circuit rather easily.   Sincerely,   
  Chris Juried  
Audio Engineering Society (AES) Member  
InfoComm-Recognized AV Technologist
http://www.JuriedEngineering.com (Juried Engineering, LLC.)

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      From: "rburnett at richieburnett.co.uk" <rburnett at richieburnett.co.uk>
 To: Jean Bender <lofideadbeat at gmail.com> 
Cc: synth-diy DIY <synth-diy at dropmix.xs4all.nl>
 Sent: Saturday, February 27, 2016 9:12 AM
 Subject: Re: [sdiy] Advices for restoring an old Roland SH2
   
Maybe someone has plugged it into a faulty "live" valve amplifier or 
something and it has burned off the ground trace to the line out jack on 
the back of the synth.  That's what I think had happened to my SH-09 
when I got it.  The ground trace to the line out jack was completely 
vaporised off the little board that the jacks are mounted on.  The only 
thing I can imagine that would cause that kind of damage is having mains 
power plugged into it somehow.  Fortunately soldering a wire along the 
route of the previously fused track, brought the line out jack back to 
life and removed the 50Hz buzz from the output.

It's quite a thin trace from what I remember so probably wouldn't take 
THAT much current to burn it open-circuit.  I'm sure things would have 
been different if the jack sockets had been electrically connected to 
the chassis, instead of having little plastic insulating washers around 
them where they pass through the metal enclosure.

-Richie,

On 2016-02-27 13:28, Jean Bender wrote:
> Hi !
> 
> I've got a Roland SH2 to fix. It's working propoerly, except a "buzz"
> that appear around the 50hz  : this buzz is always here once the synth
> plugged. I imagine a problem around the power distribution ? I should
> chek all the caps and replace some of them ?
> 
> Also, the main output has no gain, and i have to use the headphone
> output. Would somebody have an idea about that ?
> 
> Thanks for any advice or answer !
> Best.
> J.
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