I have 3 Polaris keyboards, on 2 it has been necesary to replace the
sample-hold capacitors to fix detuned voices. The process isn't for
the faint of heart (it requires replacing 12 or maybe even 24
capacitors) on the boards parts cost is about $24 but it takes almost 2
hrs to complete the repair. Another sign of the problem are certain
notes that seem to slide into pitch.

I think I posted more on the issue about a year ago but I would
recommend to skilled solderers only.

-Ben

> After I played with it for about 1/2 an hour, I pressed the "tune all"
> button. Afterwards, certain notes were out of tune with the others.
>
> I pressed the tune one button, but it doesn't fix it.
>
> Any ideas?