Archive of the former Yahoo!Groups mailing list: Rhodes Chroma Polaris

previous by date index next by date
previous in topic topic list  

Subject: Re: [chromapolaris] Re: Left membrane panel woes

From: James Lonano Yahoo <fl_799@...>
Date: 2013-08-15

I should have a few spare board connectors for the ribbon cables in my stash if anybody is in need, give me a shout.  Both sizes.....exact replacements for the originals. Always free to fellow Polaris owners.

James

Sent from my iPad

On Aug 15, 2013, at 3:54 PM, "Paul D. DeRocco" <pderocco@...> wrote:

 

> From: minimelisma
>
> Thanks, Paul. I finally found some free time and was able to
> resolve the panel issue. I'm happy to report that the problem
> was just a remnant of the old tail clogging the connector, as
> you said. Didn't need to break out the multimeter for that! I
> knew it wasn't your panels, but some stupid mistake on my
> part that was to blame.

In one way I'm glad I was right about there being some junk in the
connector, but in another way I'm not, because it means I've got to
explain to future customers that the job of replacing the panels might be
a little more difficult in some cases. In the spare Polaris that I just
set up for testing membrane panels, I had one connector that had a
fragment of the old tail in it that I simply couldn't get out, and I had
to replace the connector, which is an easy soldering job for me, but not
for everyone.

> On the other hand, I'm still having trouble resolving two
> other unrelated issues: The mod/pitch levers still aren't
> responding and the linear potentiometer Syntaur.com sent me
> (the same as pictured on their site) to replace the
> "assignable control" slider doesn't seem to match the old
> component. It's not as wide, and the pinout doesn't match up.
> Strange. The only thing I can think to do is rebuild the old
> one using the internals from the new one. I'll let you guys
> know if that works out, but I'm still clueless about the
> mod/pitch issue. Seems like they should be functioning, as
> they even still have their... springiness about them.

I seem to recall that originally we used some larger sliders, more like
the Chroma's, which had brass-colored metal casings and shafts. If you
could measure the spacing of the mounting holes on the PC board, I could
look through my old junk and see if I have anything that would line up
with those holes.

As to the levers not responding, the first thing to do, if you haven't
already done it, is to do the lever cal, as shown on page 6-2 of the
service manual. If that doesn't fix it, then measure the voltage on the
wiper of each pot, and make sure that it is in the neighborhood of 2.5V at
rest. If everything's at zero volts, then you've got a connector problem
somewhere. If it's nonzero, but nowhere near 2.5V, then you may have a
mechanical misadjustment, which you fix by loosening the nut and turning
the body of the pot until you get around 2.5V in the center position.
You'll have to pop out the springs to do this.

> Also, my unit still has what I believe are the original
> D-cell batteries? Matsushita brand? Remarkably, they're still
> working, and show no signs of corrosion, but I just know that
> they should be replaced at this point.

Might as well put in new ones. The old ones may be approaching the point
where the RAM might start dropping bits, even if it's not showing any
corrosion.

--

Ciao, Paul D. DeRocco
Paul mailto:pderocco@...