Korg Poly800/EX800 Users

--- In korgpolyex@y..., "soymuycortez" <cortes01@h...> wrote:
[edit]
> But alas, it has stopped working, I can only seem to be getting
> noise and resonance, so I suspect the DCO's are gone. Can anybody
> point me in what direction I should go, I did reload the memory
tape
> and all the time I'm getting a "GOOD" message, and the patches
seems
> to be different with the different banks I'm loading (I have the
> original tape plus some by Kid Nepro). This particular unit has a
> battery for memory back up and it has good charge (3.1 v)
> Thanks
> Jorge

hi jorge,

welcome to the list! sorry to hear about your problem - i hope it
works out. here are the things i'd suggest you try:

1. open the synth and look for any dry solder connections or shorted
connections. if your poly's in anything like the condition mine was
in you'll probably want to blow some of the dust out of the way at
this stage, also.
2. look for any obviously dead parts (i.e. melted things), and try
replacing any you find. some components just get old and die; i
guess this could be it. if you know what you're doing, have a look
at the schematic and check voltages across different components etc,
to make sure they're the correct values and haven't died.
3. again if you know what you're doing, have a look on the schematic
diagrams available in the files section. there are a few probe
points on there, with diagrams showing ideal oscilloscope readings at
those points... the point labelled "I" seems to be the osc clock
waveform, so maybe that would be one to check out, if you have a
scope. if you do this step, then even if you don't know what needs
to be done to solve the problem (and i sure as hell wouldn't), you
can at least let your technician know what you think might be wrong
(see below).
4. try to find a good technician in your area - and take the
schematics in with you when you go to see him or her. getting a tech
to fix the synth for you will probably cost lots, unless you happen
to have one as a friend, but some of these people are miracle workers
so it may well be worth the money.
5. if all else fails, keep an eye out for cheap poly-800s for sale
with broken keyboards, etc, and then if you find one, experiment with
changing the main board or individual parts over into your unbroken-
but-not-working poly... it can't hurt to try.

anyway, i hope this helps... i'm not an electronics genius by
anybody's standards, so i don't want to suggest something that turns
out to have been bad advice. i haven't spent much time looking at
the schematic, either, so i can't direct you straight to where the
DCOs are (maybe somebody else can?). good luck with your synth
though - i hope it feels better soon.

-gareth

> Hi:
> I'm new to this list but I have a modded poly800 (did the

> knobs and a noise too) I used a 100k pot for the filter cutoff, a

> for the rez, and a 250k for the noise all audio and they work

> I also added a momentary switch to the pedal so I can advance the
> programs by just pushing one button intead of having to do all the
> buttons presses to get a patch or having yet another pedal on the
> floor.
> But alas, it has stopped working, I can only seem to be getting
> noise and resonance, so I suspect the DCO's are gone. Can anybody
> point me in what direction I should go, I did reload the memory

> and all the time I'm getting a "GOOD" message, and the patches

> to be different with the different banks I'm loading (I have the
> original tape plus some by Kid Nepro). This particular unit has a
> battery for memory back up and it has good charge (3.1 v)
> Thanks
> Jorge