Rhodes Chroma Polaris

The battery backup protects also includes trim on VCAs and touch 
response of the keys.  That info is a pain to recalibrate.

You want to replace the caps labeled Polyprop. that hang off of the 
sample/hold latches (ZX01 and ZX02).

The Polaris Mother board is quite large and similar in complexity to 
other 80's computers-- the 2nd time I replaced the caps, rather then 
remove the board I just added extra solder to the leads of the 
existing caps and used reflowed them out carefully.  Afterwards I 
used a solder sucker to the clean the holes and then carefully 
soldered in new caps (with a bit of extra lead to ensure a good 
joint).  The solder will wick down into the holes.

If you want you can isolate the offending voice(s) to narrow down the 
replacement to just a few caps (use voice disable controls) but 
sooner or later all will go.

-Ben



--- In chromapolaris@yahoogroups.com, "tkrotchko" <tkrotchko@h...> 
wrote:
>
> Ah.  Now I see what you're talking about. Are these caps referred to
> as CX03-X35 and CX02-X27?  The service manual refers to them as 
mylar,
> although it shows quantity 25 and 52 of each type.
> 
> You also say "be careful not to remove the battery".  Can you 
explain
> why?  I realize the memory will be lost, but why does it matter?
> 
> Also, is there any pictures of the mainboard out there to get an 
idea
> of what I'm up against?
> 
> The symptoms that I'm seeing right now is  that if I just play right
> up the scale, I'll see every few notes just out of tune.  And its 
the
> same note every time.  Like if I play up the scale, "C" will be out 
of
> tune.
> 
> --Tom
> 
> --- In chromapolaris@yahoogroups.com, "bkuris" <benjamin.kuris@h...>
> wrote:
> 
> [...]
> 
> > The fix was to replace the S/H capacitors which are the 4 orange 
caps 
> > on either side of the TL084 opamps near the CEM voice chip.  
> > Replacement caps were panasonic polypropylene caps from 
> > www.digikey.com.   I didn't want to take out the motherboard so it
>