Rhodes Chroma Polaris

It may be a heat issue also in addition to vibration. As chips heat up they may make the connections (if compromised) more susceptible to intermittent disconnection.  
I would take a loop (magnifying glass) in a well lit area and see if any traces are broken where they connect to the sockets. Of course observing all anti-static procedures. 
Good luck

--- On Thu, 4/1/10, Paul D. DeRocco <pderocco@...> wrote:

From: Paul D. DeRocco <pderocco@...>
Subject: RE: [chromapolaris] weird memory disruption
To: chromapolaris@yahoogroups.com
Date: Thursday, April 1, 2010, 7:30 PM







 



  


    
      
      
      > From: wasteking1

>

> over the past 3 weeks my polaris has had an odd memory loss

> problem. While playing a song, particularly a section on the bass

> notes, the keyboard just stopped making  sound. and wouldnt

> respond to pushbuttons, I restarted the polaris  and  changing to

> other programs  showed that all the sounds had changed and even

> the 6 voices didnt play sounding  the same-- autotune would bring

> the voices back, but i had to reload the memory from the cassette

> to get the sounds back corectly .  this has now happenned  3

> times--- but with plenty of normal operation in between.  the

> only thing I can think of as a cause could be related to how  a

> couple months ago i did a memory chip upgrade---with new chips

> from digikey--- every thing was fine it seemed---but in pulling

> the old chips i had to pull pretty hard and i definetly was

> flexing the PC board. could i have broken some traces or solder

> joints?? and that i could loose battery power for a split second

> thus screwing up the memory?  im trying to figure this one out,

> any ideas?  The odd thing is the inconsistancy , but i think i

> was playing the same song with a rocking bass part on the low

> octave black keys when it just died---perhaps vibrating it.  does

> this make sense?



Could be. These are often tough things to diagnose. Sure sounds like a

hardware problem. If something causes the CPU to crash, it can scribble

randomly throughout the memory, including the battery backed-up part.



--



Ciao,               Paul D. DeRocco

Paul                mailto:pderocco@ix. netcom.com