The poly has a stage in its circuits that generates the +/- 9V it
uses in the analog stages, and also the +5V to power up the digital
circuits
The way that it creates these voltages in the day was fairly
standard, however these days is easily replaced by a single IC.
It is one part of that section of the circuit that fails, the hardest
part was to find a present day equivalent part number for the part
used in the circuit.
The easiest way to check if your poly is also suffering the same fate
is to check the +/- 9V at the joystick and the +5V at the IC's if you
dont see these voltages with a +9V DC centre pole power supply
attached, odds are yours suffers the same fate.
I have had some other issues on my dead korgs, however none of them
affected the board with total power loss just one stage or other in
some other part. (ie headhpones didnt work but audio out L/R worked)
One of my Korgs is still missing some parts to make it complete, and
I would welcome some parts to complete it, if anyone wants to trade
for this knowledge im keen.
Im missing a joystick, 4th and 9th white key from the bottom, top 8
white keys, top 3 black keys, and a contact pad strip.
Best Regards,
JB
On 30/05/2007, at 10:56 PM, narfman96 wrote:
> JB,
> Without divulging all your hard earned secrets what is it that
> fails in these synths?
>
> Thanks, Narfman
>
> --- In korgpolyex@yahoogroups.com, Marcus Wilson <JB@...> wrote:
> >
> > OK So i have had a few minutes and managed to debug this broken
> poly.
> >
> > It now is 3 for 3, with the new broken poly back to life with the
> > change out of 1 part.
> >
> > So dont despair! if you have a korg that is broken, and wont
> powerup,
> > there IS (i believe 99% sure) a cheap and easy fix to make it work
> > again.
> >
> > best regards,
> >
> > JB
> >
>
>
>