Rhodes Chroma Polaris

Hello

It looks like while setting up my current rig many of my synths got a midi blast of some sort. 3 of my synths behaved weirdly on the other side of this, the Chroma Polaris was one. It plays and sounds fine, but doesn’t seem to respond to midi input. Is there any reset that covers midi functions but doesn’t lose the tuning? The calibration is correct and I’d hate to try to recreate it via the service method just to get the midi responding. Any suggestions most welcome. I’ll dig into this tomorrow. It had previously been working wonderfully so I know all of the hardware is fine.

> From: paul@...
> 
> It looks like while setting up my current rig many of my 
> synths got a midi blast of some sort. 3 of my synths behaved 
> weirdly on the other side of this, the Chroma Polaris was 
> one. It plays and sounds fine, but doesn’t seem to respond to 
> midi input. Is there any reset that covers midi functions but 
> doesn’t lose the tuning? The calibration is correct and I’d 
> hate to try to recreate it via the service method just to get 
> the midi responding. Any suggestions most welcome. I’ll dig 
> into this tomorrow. It had previously been working 
> wonderfully so I know all of the hardware is fine. 

Just go through the settings starting on page 91 of the Owners Manual, and make sure they're all set the way you want. You'd have to do this even if you erased the memory, but there's nothing MIDI-related that aren't covered by the functions listed in this part of the manual. In particular, you should try Omni Mode, since that will eliminate any channel selection issues.

-- 

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

Many thanks for the help
I’ve come to find the problem is bigger than I realized. When I first turn on the Chroma Polaris I can play a few notes and then about 5 notes in the note gets held / stuck and the entire synth is locked up and unresponsive. It has the new membrane panels on it and had been fully restored about two years ago. But somewhere around 5 to 10 seconds after being turned on it locks up. Prior to that point all membrane buttons appear to work and the sounds are correct. I’ve tried lower function 12 to reset it but that doesn’t change anything. Is there anything I should re-seat or switch the battery out or other troubleshooting I could do. Recently this was working fantastically so this is a disappointment.

Hi -

One thing that bothered me for about 2 weeks was this:

The ribbon cables on the right side were touching the output board -or- coming in close contact.  This seemed to shut down everything and lock it up.  I put a new membrane on it and it worked fine except for this.  I checked every contact at the pin level of each ribbon.  The contacts were in sync witht he specs.

The left side ribbon cables are already - or should be tucked under the board.  No problem there.  Leave them alone, unless they have come out of the connectors.

The right side ribbbons looped pretty low and I said to self "no - it can't be....".  It was.  I tucked the ribbons on the right side under the board and it fired right up, stayed on, did not lock up and I loaded 3 banks of patches into it to test it out.   This info I passed on to Paul D.  and he agreed that it was possible to short out the connections on the cable(s).  Who'da thunk it, eh?  It seems that not all Polaris have the same space between the cable loop and the output board -or- someone else fiddled with it before I got it.  Normally, a repair guy wouldn't take heed to this because the original cables looped instead of being tucked under.

Open the top and see if the ribbons on the right are looping LONG towards the output board.  If they loop almost to the board, tuck them CAREFULLY under the board.  Also make sure they are seated correctly and the connections line up.  Very easy test for a BIG return on the investment.  I ran all the diagnostics and they worked fine.

No guarantees on this, but in my case it worked flawless.  Considering me pulling every chip and reseating them and doing some other tests.  It's worth a look.  Regular and philips screwdriver is all you need to open the case.

Tracy Barber
(Novice repair guy)


--------------------------------------------
On Wed, 10/10/18, paul@paperstreetaudio.com [chromapolaris] <chromapolaris@yahoogroups.com> wrote:

 Subject: RE: [chromapolaris] Responding to midi problem
 To: chromapolaris@yahoogroups.com
 Date: Wednesday, October 10, 2018, 10:19 PM
 
 
  
 
 
 
   
 
 
     
       
       
       Many thanks for the help
 
 I’ve come to find the problem is bigger than I realized.
 When I first turn on the Chroma Polaris I can play a few
 notes and then about 5 notes in the note gets held / stuck
 and the entire synth is locked up and unresponsive. It has
 the new membrane panels on it and had been fully restored
 about two years ago. But somewhere around 5 to 10 seconds
 after being turned on it locks up. Prior to that point all
 membrane buttons appear to work and the sounds are correct.
 I’ve tried lower function 12 to reset it but that
 doesn’t change anything. Is there anything I should
 re-seat or switch the battery out or other troubleshooting I
 could do. Recently this was working fantastically so this is
 a disappointment. 
 
     
      
 
     
     
 
 
 
 #yiv8718052850 #yiv8718052850 --

> From: paul@...
> 
> I’ve come to find the problem is bigger than I realized. When 
> I first turn on the Chroma Polaris I can play a few notes and 
> then about 5 notes in the note gets held / stuck and the 
> entire synth is locked up and unresponsive. It has the new 
> membrane panels on it and had been fully restored about two 
> years ago. But somewhere around 5 to 10 seconds after being 
> turned on it locks up. Prior to that point all membrane 
> buttons appear to work and the sounds are correct. I’ve tried 
> lower function 12 to reset it but that doesn’t change 
> anything. Is there anything I should re-seat or switch the 
> battery out or other troubleshooting I could do. Recently 
> this was working fantastically so this is a disappointment. 

If you have the older version of the power supply with the LED on it, the first thing is to see if the LED goes out when the instrument freezes. If that's the case, it's merely a matter of readjusting the related trimmer R17 by turning it a few degrees to the right.

If the LED is still on, the next possibility is that the EPROMs have faded. If you have access to an EPROM eraser and programmer, you can simply reprogram them, using the files from the rhodeschroma.com web site.

There are lots of other remote possibilities, which can require test equipment to diagnose. I have a Polaris that only starts up about 50% of the time, but if it starts up it continues to run fine. I haven't been able to figure that one out, even with a scope, and I designed the damn thing.

-- 

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

Mine is a Chroms Polaris II. The EPROMs day rev 5. Are they the same EPROMs as in a Chroma Polaris (v1)? 

If so I’m happy to buy an eprom burner and update to the newer versions at the site. If there is an affordable burner anyone here could recommend for this task I’m game to have one at my workbench given the amount of vintage gear I have. 

Anyhow checking the cables and EPROMs are good starting points that I can tackle before having to bring it to a shop.

Any one got any pointers on burning EPROMs.
I will just get an inexpensive eraser and burner off eBay. 
Can I use the original EPROMs inside my Polaris. Just take the stickers off to expose the top bit then erase them and reburn? 
Any version of the OS the best to burn my Polaris is a later one with newer power board..

> From: conor.strachan@...
> 
> Any one got any pointers on burning EPROMs.
> I will just get an inexpensive eraser and burner off eBay. 
> Can I use the original EPROMs inside my Polaris. Just take 
> the stickers off to expose the top bit then erase them and reburn? 
> Any version of the OS the best to burn my Polaris is a later 
> one with newer power board..

If the EPROMs are faded, that doesn't mean they're no good, so you should be able to erase and reprogram them and get another 20 years out of them. And use the latest version here:

http://www.rhodeschroma.com/?id=polariseproms

-- 

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

Thanks Paul will just use the originals! Makes it easy.

I don’t know if it’s the EPROMs that’s the problem but i am running out of things it could be as I’m just getting freezes after about 20 seconds. Tried lots of different things, everything seems to be ok on multimeter. I had the new panels put in but it was working for about 9 months after that. Fingers crossed! 
And the membrane tails are not shorting it because it’s all out on bench..

That's good to know.  Onward, Polaris warrior!

Tracy


--------------------------------------------
On Fri, 10/19/18, conor.strachan@... [chromapolaris] <chromapolaris@yahoogroups.com> wrote:

 Subject: RE: [chromapolaris] Responding to midi problem
 To: chromapolaris@yahoogroups.com
 Date: Friday, October 19, 2018, 6:42 PM
 
 
  
 
 
 
   
 
 
     
       
       
       Thanks Paul will just use the originals! Makes it
 easy.
 
 
 
 I don’t know if it’s the EPROMs that’s the problem but
 i am running out of things it could be as I’m just getting
 freezes after about 20 seconds. Tried lots of different
 things, everything seems to be ok on multimeter. I had the
 new panels put in but it was working for about 9 months
 after that. Fingers crossed! 
 
 And the membrane tails are not shorting it because it’s
 all out on bench..
 
 
 
     
      
 
     
     
 
 
 
 #yiv2909149080 #yiv2909149080 --