Korg Poly800/EX800 Users

On 29/07/12 12:20, Martin Ator wrote:
>
>
> You just have an unregulated power supply. When it starts working the
> volts will drop down to about 10 or 11. It's high because your poly
> isn't using any power.
>
> If you are measuring that voltage at Q1 then power is getting there.You
> need to see if power is getting out now?
>

Yeah, if there's nothing across C3/C4 then nothing is getting through 
that regulator transistor.  I'd have that out and replace it.

The 9V/12V thing is because off load the capacitors in the power supply 
charge up to the peak voltage, which is 9*sqrt(2), 9*1.4142 = 12.7ish 
volts.  The transformer is 9V RMS which should be about right on load.

-- 
Gordonjcp MM0YEQ