Aha, I couldn't figure out the polarity of the cap by looking at it either... it wasn't until I checked somebody else's mod photo that I saw the cap was in the other way to how I had it.
If it's non polar then that's good news! Except now I'm going to have to go and check everything else again (yup, CN6 and CN7 are properly connected - unfortunately).
Okay - I don't know if this makes any difference, but my Poly800 is an early domestic Japanese model (it does not have the two convenient solder points for mounting a battery in the centre of the board). The chip I wired into is not a 2069 AD 5066, it's labelled "Korg NJM2069D3006" - I couldn't find any reference to this number online, and since the circuit board appears to be identical I assumed it to be the same chip but maybe a batch sourced from somewhere else.
I hope that wasn't a mistaken assumption...
--- In korgpolyex@yahoogroups.com, "narfman96" <narfman96@...> wrote:
>
> Even the Poly-800 schematic shows "NP" for non polar. Any which way but loose... ;-)
>
> --- In korgpolyex@yahoogroups.com, "korgpolyex800" <korgpolyex800@> wrote:
> >
> > Hi Anthony,
> >
> > If you don't plug the two cables (CN6 and CN7) from the main board into the chorus board then you won't get any much audio at all. So check that as it's a simple mistake that I've done myself.
> >
> > I would like to know how you worked out which way around the cap is marked because, as far as I can tell, it's a non polarised electrolytic. The circuit diagram shows no polarisation and after spending quite some time with a magnifying glass, I concluded that it is not polarised. So from my experience, it doesn't actually matter which way you insert it. And would like to hear from anyone else that has an opinion on that one. :-)
> >
> > Mike
> >
> >
> >
> >
> >
> > --- In korgpolyex@yahoogroups.com, "anthonyflack@" <anthonyflack@> wrote:
> > >
> > > I don't really know a lot about electronics, but I can use a soldering iron and I've done a bit of minor modding of things in the past. I had previously installed the moog slayer mod and lithium battery backup into my Poly800, and was really happy with the results. So the other day I decided to put in the 12/24 db switch.
> > >
> > > I had run out of shrink-tubing, so I took C103 right off the board and installed it switch-side. Except in a moment of idiocy I put the capacitor in backwards...
> > >
> > > When I switched it on, the synth was still outputting, but really, really quietly (except for an initial "pop" when notes were triggered). Oh no! I opened it up spotted that I'd put the cap in backwards. I switched it around again but as I feared it was still doing the same thing.
> > >
> > > Figuring I had probably busted the capacitor, I went into town and got a replacement. They didn't have any 10uF 16v caps, so I substituted two 22uF 25v ones, connected in series, instead. Which I think should be ok?
> > >
> > > Anyway I put them in, definitely the right way around this time, but it's still making that same noise, or lack of noise. The wiring all seems to be fine and I can't see any shorts. So now I'm thinking maybe I caused another nearby component to fritz when I put the cap in backwards. If you turn the volume right up, you can hear that the keyboard is still making the right noises, so I'm hoping that it can be saved.
> > >
> > > If anybody with a proper understanding of electronics has some insight as to what has gone wrong and what I could do to remedy it, it would be gratefully received.
> > >
> >
>