Vintage Synth Repair

Do you have instrument connected through MIDI (both cables) to  
computer, hardware sequencer or any MIDI system? Or all those symptoms  
are there always, even without MIDI connection? Do your other  
instruments connected through MIDI have similar problems? Is there  
some kind of MIDI loop in your connection?

Probably this is OK. I wrote is because once I had terrible problem  
with one of my instruments and in the end I've found MIDI loop which  
caused it.

Another attempt:
Have you tried instrument diagnostics - test mode?
Have you done software reset?

Was instrument always used, and suddenly that problem started, without  
any obvious reason? Or was instrument not used for some time?

In any case I would do test, soft reset, and if it doesn't help:

Open it, put the RAM backup battery off for a night, maybe change for  
new one, than again test, reset, load proper data (factory data, or  
such data you are sure they are OK).

Anytime you can check and clean all cable connectors inside, reseat  
IC's in sockets...

Another candidate for checking is power supply.

If your OS is somehow damaged, it's possible to find version 6.2 OS  
image and program EPROM.

Daniel Forro



On May 18, 2012, at 6:06 PM, nemesisem@... wrote:

> Hi!!!
>
> Not sure if Korg O1Wfd is vintage yet, but here goes: My trusty  
> O1Wfd has developed an irritating error and I would very much like to
> know where to start to look for the source of the problem.
>
> It goes like this: You play a chord and there will be other notes  
> sounding in
> addition to those you have played. They play at random time (but  
> always 1-2
> sec. after you have pressed the keys for the chord you want) and  
> they often are
> one or two of the notes you used in previous chord you played. They  
> also are
> louder and slightly distorted in sound. There´s also high pitched  
> crackle in the
> background, while the "ghost notes" appear...
>
> They seem to have something to do with longer release times and  
> reverbs, because
> they hardly ever appear with short sounds with zero attack and zero  
> release,
> like "mono lead" etc. Short polyphonic sounds are OK as well, so it 
> ´s probably
> not about mono/poly mode...
>
> Combi and Prog sounds are most badly affected, but when played via  
> Seq mode
> there are much less problems. The shorter sounds are mostly  
> faultless in seq
> mode.
>
> I would imagine that someone else has also come accross this kind of
> malfunction, so I would be very thankful for any pointers for the  
> problem
> source.
>
> I downloaded all data from the factory disk, performed the data dump  
> from
> another O1 and tried to play the faulty O1Wfd via midi from other  
> keyboard, but
> the problem was always there...
>
> thanks in advance for any recommendations,
>
> cheers,
> Ami
>
>
>
>
>
>
> ------------------------------------
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