Rhodes Chroma Polaris

What I would suggest is that you use a multimeter to see if there is an electrical connection 
between the two signals that I mentioned.   You can measure between other SWSTB pairs 
to see what the resistance should be (high).   I would say do not unplug the flexes from the 
membranes, or do any cleaning or spraying until you have determined if there is a problem.
If you find a connection between those two signals that shouldn't be there, then try to figure
out where the short is.   But do your measurements first, especially since the flexes are 
somewhat fragile and you don't want to mess with them any more than absolutely necessary.

Ideally, you use a meter and an oscilloscope to make measurements that indicate
where problems lie, then you change chips, fix traces, etc to fix the problem.

Bob

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On Fri, 6/1/18, Tracy Barber adirondack_pc@yahoo.com [chromapolaris] <chromapolaris@yahoogroups.com> wrote:

 Subject: Re: [chromapolaris] OK - I Have Diagnostics Now And They Are Weird
 To: chromapolaris@yahoogroups.com
 Date: Friday, June 1, 2018, 12:58 AM
 
 Bob -
 
 I actually have them here. 
 Section 9 of the service manual has the pairs.  That's
 where I got the info, from the site.  You have a good
 idea, however...  I was looking at these but didn't
 come up with any way to do anything with them.  Your
 example would be "J" and "K", vibrato and pitch pedal, glide
 and rate pedal if you put all the cross overs together.
 
 So, you're saying check out the ribbon
 cables again for anything out of the ordinary?  That I
 can do.  Clean them with alcohol, yes?
 
 I sprayed the connectors with canned
 air and used a little Deoxy D5 on them to clean them up
 already.  Made sure they were in and lined up
 properly.
 
 Unfortunately, I can't check the side
 that is connected to the face plates because they're buried
 under the material.  Also, they're brand new. 
 Sheesh...  I also did the "S" curve as told to by the
 video.   I sure wished they would've spent a few more $
 on real connectors.  You also can't get a swab in there
 to clean the contacts better.  I wonder if an alcohol
 pad would work?
 
 Tracy
 
 **** 
  
  
  If you go to this site, and scroll
 down to the bottom, you
  can see the connections to the front
 panel membrane
  switches.
  
  These are not shown in the service
 manual schematics.
  
  
  
  http://www.rhodeschroma.com/?id=polarisserviceschematics
  
  
  
  If you look at switches A and G you
 will see that one end of
  each is common, and only the other end
 is different.
  
  One connects to J9A-3 SWSTB4 and the
 other connects to J9A-4
  SWSTB5.   If something is
 shorting those two
  
  signals together, such as a solder
 splash, or possibly a bit
  of the old membrane flex still in the
 connector, then when
  
  
  you press G, you could get an A. 
  A lot of other pairs of
  switches would also be joined by such
 a short.   I suggest
  
  
  you troubleshoot the front panel issue
 and get it resolved
  before trying to troubleshoot anything
 else.  A DMM
  measuring 
  
  resistance should help to see if there
 is some kind of short
  between those two signals.
  
  
  
  Bob
  
   
  
  
  
      
       
  
      
      
  
  
  
  #yiv2966711545 #yiv2966711545 --