Rhodes Chroma Polaris

First of all, let me apologize for my Yahoo username. I picked this
name when I was 17 or so in 1999.

I've owned my Polaris for about a year now, and it has the infamous
membrane button death. I've opened it up a time or two but not gotten
too adventerous until tonight. Long story short, the jumpers
connecting the PCB to the membrane panel are pretty much dead (deader
than they were). But when I say "jumper" I mean "leads in a thin
plastic sheet."

Can I simply solder in some jumper cable or wires from the PCB to the
membrane panel or do I need to think about using this machine for
spare parts?

I may be able to articulate this better with photographs, which may
have to wait until someone posts a reply.



Thanks,

AAB

From: "teknowh0re_1999"
...

> I've owned my Polaris for about a year now, and it has the infamous
> membrane button death. I've opened it up a time or two but not gotten
> too adventerous until tonight. Long story short, the jumpers
> connecting the PCB to the membrane panel are pretty much dead (deader
> than they were). But when I say "jumper" I mean "leads in a thin
> plastic sheet."
>
> Can I simply solder in some jumper cable or wires from the PCB to the
> membrane panel or do I need to think about using this machine for
> spare parts?

If the problem is with one or more of the plastic strips that come from the
front panel and slide into connectors on the circuit boards, then soldering
will be tough.

The plastic/mylar normally has a conductive coating on it, and that's what
transfers the signals to the circuits.

The most common polaris sickness will be a cracking of that plastic - and as
the plastic cracks, the signal traces are broken. In many cases, the
cracking occurs at the end of the connections - and so you can get lucky by
trimming off the bad end with a pair of scissors.

If the crack/rip/tear is too far away from the connectors to make cutting
likely, then there are a couple alternatives:

1) Try to physically repair the crack by gluing/attaching another piece of
plastic to the broken piece. This will not necessarily repair the
electrical conductivity, but it will be the mechanical support for the
connection. Once mechanically secure, the trace itself can sometimes be
repaired via a 'conductive ink pen'. They sell these at electronics stores
(and on-line), and they're specifically made for this sort of a task. You'd
hold them like a pen, and then 'draw' the connections you need. Once dry,
the connections can pass the signals you need.

2) A slight variation of #1 (and this is if you're desperate), would be to
try to 'stitch' a fine wire back and forth between the broken track. (Think
of it just like a needle and thread - but instead of holding material
together, you'd be holding the traces together). Certainly not ideal, and
depending how brittle the connector is, may cause more damage than it fixes.

You can have even more variations, with wires being fished up between the
layers of the front panel - but these are really last-gasp sort of
solutions.

3) If all else fails, then you'd be looking to forego the use of the actual
membrane switches, and to add in your own switches (which you'd wire in with
real-wire instead of the plastic). These switches could be mounted right
on/through the original panel, or they could go in an external box.

In the short-term, it is the case that the parameters can be controlled from
MIDI - so an external MIDI knob-box (or access from a sequencing program)
could be used.

Thanks. I am unable to control anything bute note changes and
transpose functions via MIDI, which is why I was buggering around
inside in the first place. I would have no issue if I could access
all the functions, but for some reason I am unable to do so when I
attempt control from another synth.

I have a fairly lengthy document regarding cc's and what not for this
machine, but to be honest I'm not familiar with sending these types
of messages from a software controller.

--- In chromapolaris@yahoogroups.com, David Clarke <ac151@...> wrote:
>
> From: "teknowh0re_1999"
> ...
> > I've owned my Polaris for about a year now, and it has the
infamous
> > membrane button death. I've opened it up a time or two but not
gotten
> > too adventerous until tonight. Long story short, the jumpers
> > connecting the PCB to the membrane panel are pretty much dead
(deader
> > than they were). But when I say "jumper" I mean "leads in a thin
> > plastic sheet."
> >
> > Can I simply solder in some jumper cable or wires from the PCB to
the
> > membrane panel or do I need to think about using this machine for
> > spare parts?
>
> If the problem is with one or more of the plastic strips that come
from the
> front panel and slide into connectors on the circuit boards, then
soldering
> will be tough.
>
> The plastic/mylar normally has a conductive coating on it, and
that's what
> transfers the signals to the circuits.
>
> The most common polaris sickness will be a cracking of that
plastic - and as
> the plastic cracks, the signal traces are broken. In many cases,
the
> cracking occurs at the end of the connections - and so you can get
lucky by
> trimming off the bad end with a pair of scissors.
>
> If the crack/rip/tear is too far away from the connectors to make
cutting
> likely, then there are a couple alternatives:
>
> 1) Try to physically repair the crack by gluing/attaching another
piece of
> plastic to the broken piece. This will not necessarily repair the
> electrical conductivity, but it will be the mechanical support for
the
> connection. Once mechanically secure, the trace itself can
sometimes be
> repaired via a 'conductive ink pen'. They sell these at
electronics stores
> (and on-line), and they're specifically made for this sort of a
task. You'd
> hold them like a pen, and then 'draw' the connections you need.
Once dry,
> the connections can pass the signals you need.
>
> 2) A slight variation of #1 (and this is if you're desperate),
would be to
> try to 'stitch' a fine wire back and forth between the broken
track. (Think
> of it just like a needle and thread - but instead of holding
material
> together, you'd be holding the traces together). Certainly not
ideal, and
> depending how brittle the connector is, may cause more damage than
it fixes.
>
> You can have even more variations, with wires being fished up
between the
> layers of the front panel - but these are really last-gasp sort of
> solutions.
>
> 3) If all else fails, then you'd be looking to forego the use of
the actual
> membrane switches, and to add in your own switches (which you'd
wire in with
> real-wire instead of the plastic). These switches could be mounted
right
> on/through the original panel, or they could go in an external box.
>
> In the short-term, it is the case that the parameters can be
controlled from
> MIDI - so an external MIDI knob-box (or access from a sequencing
program)
> could be used.
>