Rhodes Chroma Polaris

Hello All,
I too have a Polaris which I’ve added new membrane panel to.
Initially it was all frozen, gradually by power cycling (and getting to the tune function etc) it will go a few minutes before crashing in the same manner as described by Conor.
All my voltages appear good. So Paul do you suggest psu ripple or faded EPROMs as probable causes?
I calibrated my DAC (dc offset) which made it better but the machine still crashes without fail. I thought I would chime in here as it might be a common issue caused by ??
Thanks!

Sent from my iPhone

> On 13 Jul 2018, at 12:15, 'Paul D. DeRocco' pderocco@... [chromapolaris] <chromapolaris@yahoogroups.com> wrote:
> 
> > From: Conor Strachan [mailto:conor.strachan@...] 
> > 
> > I am having a few issues with my Polaris, it has the new 
> > membrane panels and was working fine for over a year and then 
> > all of a sudden it started to play up.
> > 
> > It is turning on and then after about 10 seconds the panel is 
> > freezing along with the notes sustaining or gliding then sustaining.
> > 
> > I am consulting the service manual but there is a lot of 
> > reference to the older secondary power board and I have the 
> > later one so it is a little confusing.
> > 
> > I have checked my DC OK which I believe should be +5v (brown 
> > wire P3) but it goes to about +4.75v when it is first turned 
> > on with panel access then it fluctuates up to 4.80v and it 
> > stays around the +4.80v mark where the panel is frozen.
> > 
> > According to the manual it says there is no way to adjust 
> > anything on the DCOK side on the later boards. 
> > 
> > Just wondering if you have any suggestions of where to go next..
> 
> Does it ever unfreeze spontaineously, or do you have to cycle the power to get it going again?
> 
> I doubt it's a DCOK problem. You should check all the power supply voltages. If you have access to a scope, you should also make sure that the supplies have no significant power line ripple on them. That can happen when the big caps on the power supply dry out.
> 
> It's also possible that the EPROMs are fading. That can be fixed by erasing them and reprogramming them with the files available on the rhodeschroma.com site. If you don't have a programmer, and can't find someone nearby who does, they're available on eBay for about $50.
> 
> I've cc-ed this to the mailing list, so that others can put in their two cents.
> 
> -- 
> 
> Ciao, Paul D. DeRocco
> Paul mailto:pderocco@...
> 
>