Check that you can hear the detune functions working 38 ,0-3 properly. No detune on 0 then some on 1 , more on 2 and most on 3.Check for battery acid damage on the circuit board, rusty IC pin in the middle of nice shiny ones etc.
On Friday, 27 February 2015, 10:19, "gordon@... [korgpolyex]" <korgpolyex@yahoogroups.com> wrote:
On Fri, Feb 27, 2015 at 01:59:20AM -0800, borislav.wurst@... [korgpolyex] wrote:
> hi
>
> it is the coil for tuning
>
>
> the powersupply is fine! works perfectly on my ex800
>
>
> the voltages are right, -5 and +5v coming directly after turning on.
>
>
> what else wonders me is that it sounds like the filter frequencies is sweeping up with the tune...
>
Can you measure the filter CV as you power it up? Could it be heat related?
It's time to get oldschool, the way we used to fix drifty problems in TVs and VCRs back when we fixed them instead of throwing them out. Get at it with a tin of freezer spray and a hair dryer. Gently heat and cool bits until you find one that seems excessively sensitive to heat.
I'd put a very small wager on you finding that it's either a regulator tranny or a disc ceramic capacitor somewhere in the PSU.
--
Gordonjcp MM0YEQ