> 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@...