Rhodes Chroma Polaris

Ben,

Thanks so much for that detailed explanation.

It sounds like by leaving the motherboard in, you don't have access to
the trace side, so you just let the solder flow down into the holes. 
I would not have thought to do that.

Does removing the MB really add that much time to the repair?

Back to the parts themselves... are the values accurate in the service
manual?  You wouldn't happen to have part #'s at digikey would you?

[btw, I just repaired an Apple graphite Wifi basestation.  The two
electrolytics in the PS cook themselves after a few years. The board
is multi-layer and it was a real pain to get the solder out of them. 
A simple repair that should have been 15 minutes turned into 90
minutes because I had to use a dremel drill to get the solder out. 
Apple charged me enough for the base station...couldn't they have
included higher quality caps?]

--- In chromapolaris@yahoogroups.com, "bkuris" <Bkuris@g...> wrote:
>
> 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
>