Korg Poly800/EX800 Users group photo

Yahoo Groups archive

Korg Poly800/EX800 Users

Index last updated: 2026-04-28 23:27 UTC

Message

Re: DCO's death? HELP!

2002-09-09 by funkwit

--- 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

Attachments

Move to quarantaine

This moves the raw source file on disk only. The archive index is not changed automatically, so you still need to run a manual refresh afterward.