Rhodes Chroma Polaris

hello all . 
im about to take the plunge and attempt to rebuild the front panel . replacing all buttons 
to get my polaris back in service . 
i have very basic soldering skills and even more basic knowledge of electronics (that 
makes it sound like a bad idea;)
anyway, i have downloaded the "chroma polaris panel button wiring matrix" PDF but have 
a few questions .
to anyone thta has rebuilt their front panel :
-what do the "SW" and "STB" signify on the PDF ? are these different types of switches ?
-what kind of electronic parts / switches to i need ? are they on/off or merely a 
momentary style switch (not sure of the correct terminology here) .
-what kind of size or depth switch would anyone recommend ?
-im assuming "J9A" , "J9B" , "J8A" and "J8B" are the connections on the PCB where the nasty 
fragile ribbon connectors would originally connect . which is which ? is this marked on the 
circuit board ? and are the connections counted from left to right / top to bottom or how ?

i guess it is then a matter of building a rats nest of wiring to connect the switches to each 
connection on the PCB . 
would i have to connect the switches "the correct way round" or do they connect either way 
round ?

apologies for so many questions, and if they seem very basic . i would like to check 
everything over thoroughly before i attempt this repair . 
to anyone who has completed a successful polaris facelift that could guide me through i 
would really appreciate the help . 

many many thanks in advance .

> From: alex459686
> 
> -what do the "SW" and "STB" signify on the PDF ? are these 
> different types of switches ? -what kind of electronic parts 
> / switches to i need ? are they on/off or merely a 
> momentary style switch (not sure of the correct terminology 
> here) .

The switches need to be momentary, normally-open, pushbutton switches. They
are arranged in a two-dimensional 8x8 matrix, each switch connecting one of
the STB (strobe) outputs from the circuitry to one of the SW (switch data)
inputs back to the circuitry. At any given instant, all the STB outputs are
floating except for one, which is grounded; and all the SW inputs are pulled
up to +5V through resistors. The STB output that is grounded selects a bank
of eight switches, and any of those that are pressed pull the corresponding
SW input to ground. The computer cycles through all eight banks at a rapid
rate. It's a standard multiplexing mechanism.

> -im assuming "J9A" , "J9B" , "J8A" and "J8B" are 
> the connections on the PCB where the nasty 
> fragile ribbon connectors would originally connect . which is 
> which ? is this marked on the 
> circuit board ? and are the connections counted from left to 
> right / top to bottom or how ?

I don't have mine handy, but the connectors should have J numbers next to
them, and there should be some indication of which pin is 1, perhaps a dot
next to the pin, the digit 1, or maybe just a square PC pad for that pin
instead of the usual round or oval one.

> i guess it is then a matter of building a rats nest of wiring 
> to connect the switches to each connection on the PCB . 

It may look like a rat's nest, but it's really just an 8x8 matrix. The SW
lines on J8B just duplicate seven of the SW lines on J9B, so you can just
use J9B. Each SW line goes to (at most) eight switches, and each STB line
goes to (at most) eight switches.

> would i have to connect the switches "the correct way round" 
> or do they connect either way round ?

Well, it's certainly essential that, for instance, the "Upper Function"
switch connect to SW1 and STB7, as opposed to STB1 and SW7, but it doesn't
matter which pin on the switch goes to which.

-- 

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

many many thanks for the advice Paul .
I will research, and brush up on my electronics know-how before attempting this .

For anyone with good internal Polaris know-how and free time....::::
The Issue my Polaris is having right now, is that when it is switched on the vast majority of 
panel lights are "lit", buttons "7" , "8" and "9" seem to work but they have the response of 
changing "assignable control" light (of which only one is ever alight) and also the 
"envelope" and "volume envelope" lights . This is very odd, i have previously experienced a 
damaged ribbon which i , at first , successfully repaired . but now seems damaged again .
another odd trait of my current Polaris problem is that by pressing 7,8 or 9 the sound is 
changed, though as i play the keyboard the sound suddenly changes erratically . im 
assuming due to the computer receiving confusing messages from the panel . The sliders 
then have no effect on the sound of the instrument .
I am assuming that there is some kind of problem with the Ribbon, as this is a repeating 
problem for me . and due to this problem most of the switches are active . causing the 
instrument to become "confused" and not respond to the slider changes .
does anyone have any idea what connection/cable break or ribbon damage may cause a 
response like this . In reference to the schematics  how would it be possible for all the 
right panel lights to be in there "on" state at the same time ?
sigh!...ok . i hope i didnt explain that too confusingly . . if anyone could help shed any 
light on this problem id be thankful .

thanks again for the previous info .
long live the polaris group ;)

Alex,

It sounds like paul is your "go to guy" on the Polaris electronics. I put 
mine together by following the existing switch circuit as shown on the 
original membrane panels, I don't have the depth of electronic knowledge to 
have known how the matrix works. Then i drilled the holes installed the 
switches and connected the dots. Jason reccomended the switches which i 
accessed on Ebay for very low cost. I'll find you the link to the 
manufacturer.
If anything isn't right with that matrix expect problems. I had one shorted 
switch and nothing worked until I metered out all the switches and found the 
problem. Now it all works fine. I never did like those membrane switches 
even when they worked. Not responsive or tactile enough.




>From: alex459686 <no_reply@yahoogroups.com>
>Reply-To: chromapolaris@yahoogroups.com
>To: chromapolaris@yahoogroups.com
>Subject: [chromapolaris] Re: any advice on rebuilding the front panel 
>needed .
>Date: Thu, 10 May 2007 01:32:45 -0000
>
>
>many many thanks for the advice Paul .
>I will research, and brush up on my electronics know-how before attempting 
>this .
>
>For anyone with good internal Polaris know-how and free time....::::
>The Issue my Polaris is having right now, is that when it is switched on 
>the vast majority of
>panel lights are "lit", buttons "7" , "8" and "9" seem to work but they 
>have the response of
>changing "assignable control" light (of which only one is ever alight) and 
>also the
>"envelope" and "volume envelope" lights . This is very odd, i have 
>previously experienced a
>damaged ribbon which i , at first , successfully repaired . but now seems 
>damaged again .
>another odd trait of my current Polaris problem is that by pressing 7,8 or 
>9 the sound is
>changed, though as i play the keyboard the sound suddenly changes 
>erratically . im
>assuming due to the computer receiving confusing messages from the panel . 
>The sliders
>then have no effect on the sound of the instrument .
>I am assuming that there is some kind of problem with the Ribbon, as this 
>is a repeating
>problem for me . and due to this problem most of the switches are active . 
>causing the
>instrument to become "confused" and not respond to the slider changes .
>does anyone have any idea what connection/cable break or ribbon damage may 
>cause a
>response like this . In reference to the schematics  how would it be 
>possible for all the
>right panel lights to be in there "on" state at the same time ?
>sigh!...ok . i hope i didnt explain that too confusingly . . if anyone 
>could help shed any
>light on this problem id be thankful .
>
>thanks again for the previous info .
>long live the polaris group ;)
>
>

_________________________________________________________________
New Windows Live Hotmail is here. Upgrade for free and get a better look. 
www.newhotmail.ca?icid=WLHMENCA150

I repaired my Polaris membrane ribbons by cutting the damaged parts 
off and carefully using a solvent(flux remover)to dissolve the 
painted green insulation and rebuilding a new termination to plug 
into the socket. One was far too short so I removed the termination 
socket from the PCB and after connection, glued it to the metal 
front panel for stability. I then soldered #22 wires to the 
connector that run to the PCB where the old connector was mounted. 
It is working well now. For awile I was thinking I might do that to 
all of the connections as the ribbons are prone to cracking where 
they loop to plug into the termination sockets. Anyway that's my 2 
cents!
Lou


--- In chromapolaris@yahoogroups.com, "greg rudd" <compactor24@...> 
wrote:
>
> Alex,
> 
> It sounds like paul is your "go to guy" on the Polaris 
electronics. I put 
> mine together by following the existing switch circuit as shown on 
the 
> original membrane panels, I don't have the depth of electronic 
knowledge to 
> have known how the matrix works. Then i drilled the holes 
installed the 
> switches and connected the dots. Jason reccomended the switches 
which i 
> accessed on Ebay for very low cost. I'll find you the link to the 
> manufacturer.
> If anything isn't right with that matrix expect problems. I had 
one shorted 
> switch and nothing worked until I metered out all the switches and 
found the 
> problem. Now it all works fine. I never did like those membrane 
switches 
> even when they worked. Not responsive or tactile enough.
> 
> 
> 
> 
> >From: alex459686 <no_reply@yahoogroups.com>
> >Reply-To: chromapolaris@yahoogroups.com
> >To: chromapolaris@yahoogroups.com
> >Subject: [chromapolaris] Re: any advice on rebuilding the front 
panel 
> >needed .
> >Date: Thu, 10 May 2007 01:32:45 -0000
> >
> >
> >many many thanks for the advice Paul .
> >I will research, and brush up on my electronics know-how before 
attempting 
> >this .
> >
> >For anyone with good internal Polaris know-how and free 
time....::::
> >The Issue my Polaris is having right now, is that when it is 
switched on 
> >the vast majority of
> >panel lights are "lit", buttons "7" , "8" and "9" seem to work 
but they 
> >have the response of
> >changing "assignable control" light (of which only one is ever 
alight) and 
> >also the
> >"envelope" and "volume envelope" lights . This is very odd, i 
have 
> >previously experienced a
> >damaged ribbon which i , at first , successfully repaired . but 
now seems 
> >damaged again .
> >another odd trait of my current Polaris problem is that by 
pressing 7,8 or 
> >9 the sound is
> >changed, though as i play the keyboard the sound suddenly changes 
> >erratically . im
> >assuming due to the computer receiving confusing messages from 
the panel . 
> >The sliders
> >then have no effect on the sound of the instrument .
> >I am assuming that there is some kind of problem with the Ribbon, 
as this 
> >is a repeating
> >problem for me . and due to this problem most of the switches are 
active . 
> >causing the
> >instrument to become "confused" and not respond to the slider 
changes .
> >does anyone have any idea what connection/cable break or ribbon 
damage may 
> >cause a
> >response like this . In reference to the schematics  how would it 
be 
> >possible for all the
> >right panel lights to be in there "on" state at the same time ?
> >sigh!...ok . i hope i didnt explain that too confusingly . . if 
anyone 
> >could help shed any
> >light on this problem id be thankful .
> >
> >thanks again for the previous info .
> >long live the polaris group ;)
> >
> >
> 
> _________________________________________________________________
> New Windows Live Hotmail is here. Upgrade for free and get a 
better look. 
> www.newhotmail.ca?icid=WLHMENCA150
>

--- In chromapolaris@yahoogroups.com, "pterodactylrecords" <lou@...> 
wrote:
>
> I repaired my Polaris membrane ribbons by cutting the damaged parts 
> off and carefully using a solvent(flux remover)to dissolve the 
> painted green insulation and rebuilding a new termination to plug 
> into the socket. One was far too short so I removed the termination 
> socket from the PCB and after connection, glued it to the metal 
> front panel for stability. I then soldered #22 wires to the 
> connector that run to the PCB where the old connector was mounted. 
> It is working well now. For awile I was thinking I might do that to 
> all of the connections as the ribbons are prone to cracking where 
> they loop to plug into the termination sockets. Anyway that's my 2 
> cents!
> Lou
> 
> 
> --- In chromapolaris@yahoogroups.com, "greg rudd" <compactor24@> 
> wrote:
> >
> > Alex,
> > 
> > It sounds like paul is your "go to guy" on the Polaris 
> electronics. I put 
> > mine together by following the existing switch circuit as shown 
on 
> the 
> > original membrane panels, I don't have the depth of electronic 
> knowledge to 
> > have known how the matrix works. Then i drilled the holes 
> installed the 
> > switches and connected the dots. Jason reccomended the switches 
> which i 
> > accessed on Ebay for very low cost. I'll find you the link to the 
> > manufacturer.
> > If anything isn't right with that matrix expect problems. I had 
> one shorted 
> > switch and nothing worked until I metered out all the switches 
and 
> found the 
> > problem. Now it all works fine. I never did like those membrane 
> switches 
> > even when they worked. Not responsive or tactile enough.
> > 
> > 
> > 
> > 
> > >From: alex459686 <no_reply@yahoogroups.com>
> > >Reply-To: chromapolaris@yahoogroups.com
> > >To: chromapolaris@yahoogroups.com
> > >Subject: [chromapolaris] Re: any advice on rebuilding the front 
> panel 
> > >needed .
> > >Date: Thu, 10 May 2007 01:32:45 -0000
> > >
> > >
> > >many many thanks for the advice Paul .
> > >I will research, and brush up on my electronics know-how before 
> attempting 
> > >this .
> > >
> > >For anyone with good internal Polaris know-how and free 
> time....::::
> > >The Issue my Polaris is having right now, is that when it is 
> switched on 
> > >the vast majority of
> > >panel lights are "lit", buttons "7" , "8" and "9" seem to work 
> but they 
> > >have the response of
> > >changing "assignable control" light (of which only one is ever 
> alight) and 
> > >also the
> > >"envelope" and "volume envelope" lights . This is very odd, i 
> have 
> > >previously experienced a
> > >damaged ribbon which i , at first , successfully repaired . but 
> now seems 
> > >damaged again .
> > >another odd trait of my current Polaris problem is that by 
> pressing 7,8 or 
> > >9 the sound is
> > >changed, though as i play the keyboard the sound suddenly 
changes 
> > >erratically . im
> > >assuming due to the computer receiving confusing messages from 
> the panel . 
> > >The sliders
> > >then have no effect on the sound of the instrument .
> > >I am assuming that there is some kind of problem with the 
Ribbon, 
> as this 
> > >is a repeating
> > >problem for me . and due to this problem most of the switches 
are 
> active . 
> > >causing the
> > >instrument to become "confused" and not respond to the slider 
> changes .
> > >does anyone have any idea what connection/cable break or ribbon 
> damage may 
> > >cause a
> > >response like this . In reference to the schematics  how would 
it 
> be 
> > >possible for all the
> > >right panel lights to be in there "on" state at the same time ?
> > >sigh!...ok . i hope i didnt explain that too confusingly . . if 
> anyone 
> > >could help shed any
> > >light on this problem id be thankful .
> > >
> > >thanks again for the previous info .
> > >long live the polaris group ;)
> > >
> > >
> > 
> > _________________________________________________________________
> > New Windows Live Hotmail is here. Upgrade for free and get a 
> better look. 
> > www.newhotmail.ca?icid=WLHMENCA150
> >
>Lou, That is the best way to fix it. I just picked up another 
Polaris yesterday with one bad membrane ribbon side. YOur method 
should work just fine and a lot less work than completely rebuilding 
the entire switch matrix from scratch like some of us have done in 
the past. Brilliant and Thanks for such a simple and effective 
solution. Can you reccomend the right solvent for the job?

Thanks
Tek

Hi,

"right solvent for the job?"

I'ved used nail polish remover with a Q-tip (cotton applicator), use 
it very very slowly and it will leave the silver conductor and remove 
the green insulation.  

Brian

Good news.  It appears I've secured a 'shell' that has good membrane
switch panel that was lying in a music store somewhere.  This guy I
know bought out like three floors of old combo organs and synths! 
Unless I get a lot of money for it though I'll probably pick off a
cheap ebay one with broken switches and just fix it up.

However in case people don't know I've had 100% success repairing
'permanently' front panels that break ribbon connectors and do NOT
have punched out switch covers.  I never documented what I do because
I figured about half the people would screw it up and permanently
destroy the unit trying it.  It is very very tricky to get my
percentage success on this operation you are attempting.  Be careful
not to stress any of that brittle material.  


--- In chromapolaris@yahoogroups.com, Brian Murray <bjmur58@...> wrote:
>
> Good luck with yours, I had a similar problem. I had to removed the
edge connector from one of the boards and re-attach wires to connect
it back to the board. I also mounted one of the connectors on the
bottom of the boards because the ribbon was too short.
>   Brian
>    
>   
> greg rudd <compactor24@...> wrote:
>           Hey Brian,
>  
> Thanks for the information. I will get some tomorrow. Much
appreciated The membrane in question has very little material left so
I'll only get on shot at it. 
>  
> Thanks again
> Tek
> 
> 
>     
> ---------------------------------
>   To: chromapolaris@yahoogroups.com
> From: bjmur58@...
> Date: Tue, 29 Jan 2008 02:58:19 +0000
> Subject: [chromapolaris] Re: any advice on rebuilding the front
panel needed .
> 
>       Hi,
> 
> "right solvent for the job?"
> 
> I'ved used nail polish remover with a Q-tip (cotton applicator), use 
> it very very slowly and it will leave the silver conductor and remove 
> the green insulation. 
> 
> Brian 
> 
> 
> 
> 
> 
> 
>   
> ---------------------------------
>     
> 
>                          
> 
>        
> ---------------------------------
> Looking for last minute shopping deals?  Find them fast with Yahoo!
Search.
>

--- In chromapolaris@yahoogroups.com, greg rudd <compactor24@...> 
wrote:
>
> 
> Brian, Thanks for the cautionary words. For me dealing with the 
edge connector is no problem. I do a lot of soldering, but the ribbon 
connector is the critical part. I will be very careful applying the 
nail polish remover. I did some testing on some ribbon I had left 
over from my other Polaris membranes. I metered out the traces after 
i was finished and had good continuity. I'll post the results when i 
have completed the repair. I'm leaving it for a weekend project. 
>  
> Thanks again :)
>  
> Tek
> 
> 
> To: chromapolaris@...: sounddoctorin@...: Mon, 4 Feb 2008 20:25:25 
+0000Subject: [chromapolaris] Re: any advice on rebuilding the front 
panel needed .
> 
> 
> 
> 
> Good news. It appears I've secured a 'shell' that has good 
membraneswitch panel that was lying in a music store somewhere. This 
guy Iknow bought out like three floors of old combo organs and 
synths! Unless I get a lot of money for it though I'll probably pick 
off acheap ebay one with broken switches and just fix it up.However 
in case people don't know I've had 100% success 
repairing'permanently' front panels that break ribbon connectors and 
do NOThave punched out switch covers. I never documented what I do 
becauseI figured about half the people would screw it up and 
permanentlydestroy the unit trying it. It is very very tricky to get 
mypercentage success on this operation you are attempting. Be 
carefulnot to stress any of that brittle material. --- In 
chromapolaris@yahoogroups.com, Brian Murray <bjmur58@> wrote:>> Good 
luck with yours, I had a similar problem. I had to removed theedge 
connector from one of the boards and re-attach wires to connectit 
back to the board. I also mounted one of the connectors on thebottom 
of the boards because the ribbon was too short.> Brian> > > greg rudd 
<compactor24@> wrote:> Hey Brian,> > Thanks for the information. I 
will get some tomorrow. Muchappreciated The membrane in question has 
very little material left soI'll only get on shot at it. > > Thanks 
again> Tek> > > > ---------------------------------> To: 
chromapolaris@yahoogroups.com> From: bjmur58@> Date: Tue, 29 Jan 2008 
02:58:19 +0000> Subject: [chromapolaris] Re: any advice on rebuilding 
the frontpanel needed .> > Hi,> > "right solvent for the job?"> > 
I'ved used nail polish remover with a Q-tip (cotton applicator), use 
> it very very slowly and it will leave the silver conductor and 
remove > the green insulation. > > Brian > > > > > > > > -------------
--------------------> > > > > > ---------------------------------> 
Looking for last minute shopping deals? Find them fast with 
Yahoo!Search.> 
> 
> 
> evenin' all, I too have shot wafer on my membranes and have been 
racking my brains on a solution (apart from butchering the front 
panel with a load of mechanical switches).The idea of relocating the 
edge connectors is a magnificent piece of lateral thinking that I 
wish had occurred to me five years ago!                         
Thanks everyone.                                         
Nick.                                                               
Now where did the missus put that nail varnish remover!

> 
> 
> 
> _________________________________________________________________
>

--- In chromapolaris@yahoogroups.com, "nickwest16" <nickwest16@...> 
wrote:
>
> --- In chromapolaris@yahoogroups.com, greg rudd <compactor24@> 
> wrote:
> >
> > 
> > Brian, Thanks for the cautionary words. For me dealing with the 
> edge connector is no problem. I do a lot of soldering, but the 
ribbon 
> connector is the critical part. I will be very careful applying 
the 
> nail polish remover. I did some testing on some ribbon I had left 
> over from my other Polaris membranes. I metered out the traces 
after 
> i was finished and had good continuity. I'll post the results when 
i 
> have completed the repair. I'm leaving it for a weekend project. 
> >  
> > Thanks again :)
> >  
> > Tek
> > 
> > 
> > To: chromapolaris@: sounddoctorin@: Mon, 4 Feb 2008 20:25:25 
> +0000Subject: [chromapolaris] Re: any advice on rebuilding the 
front 
> panel needed .
> > 
> > 
> > 
> > 
> > Good news. It appears I've secured a 'shell' that has good 
> membraneswitch panel that was lying in a music store somewhere. 
This 
> guy Iknow bought out like three floors of old combo organs and 
> synths! Unless I get a lot of money for it though I'll probably 
pick 
> off acheap ebay one with broken switches and just fix it 
up.However 
> in case people don't know I've had 100% success 
> repairing'permanently' front panels that break ribbon connectors 
and 
> do NOThave punched out switch covers. I never documented what I do 
> becauseI figured about half the people would screw it up and 
> permanentlydestroy the unit trying it. It is very very tricky to 
get 
> mypercentage success on this operation you are attempting. Be 
> carefulnot to stress any of that brittle material. --- In 
> chromapolaris@yahoogroups.com, Brian Murray <bjmur58@> wrote:>> 
Good 
> luck with yours, I had a similar problem. I had to removed theedge 
> connector from one of the boards and re-attach wires to connectit 
> back to the board. I also mounted one of the connectors on 
thebottom 
> of the boards because the ribbon was too short.> Brian> > > greg 
rudd 
> <compactor24@> wrote:> Hey Brian,> > Thanks for the information. I 
> will get some tomorrow. Muchappreciated The membrane in question 
has 
> very little material left soI'll only get on shot at it. > > 
Thanks 
> again> Tek> > > > ---------------------------------> To: 
> chromapolaris@yahoogroups.com> From: bjmur58@> Date: Tue, 29 Jan 
2008 
> 02:58:19 +0000> Subject: [chromapolaris] Re: any advice on 
rebuilding 
> the frontpanel needed .> > Hi,> > "right solvent for the job?"> > 
> I'ved used nail polish remover with a Q-tip (cotton applicator), 
use 
> > it very very slowly and it will leave the silver conductor and 
> remove > the green insulation. > > Brian > > > > > > > > ----------
---
> --------------------> > > > > > ---------------------------------> 
> Looking for last minute shopping deals? Find them fast with 
> Yahoo!Search.> 
> > 
> > 
> > evenin' all, I too have shot wafer on my membranes and have been 
> racking my brains on a solution (apart from butchering the front 
> panel with a load of mechanical switches).The idea of relocating 
the 
> edge connectors is a magnificent piece of lateral thinking that I 
> wish had occurred to me five years ago!                         
> Thanks everyone.                                         
> 
Nick.                                                               
> Now where did the missus put that nail varnish remover!
> > 
> > P.S. does anyone know where I can find a slide potentiometer of 
the correct spec for the assign. I can only find logarithmic not 
linear, or 50k not 10k in the right dimensions.I'm located in England 
so I'm  a bit limited in my supply options. 
> > Thanks again 
Nick

> > _________________________________________________________________
> >
>