Yamaha CS80

hello
I need help for my GX-1.
both of KAS boards for upper and lower
keyboards have problem and now my GX-1 can not
sound correct.

upper key keeps silence.
lower key, two octaves out of 5 sound correct,
however the others sound silence or strange.

YAMAHA here in JAPAN gave up to fix them already
and my friend in sweden does not have time to help me.

sorry to bother this message board since it is for CS80.
I hope to hear from some analogue synthe lovers......

sincerely

Kenji
YOKOHAMA city, JAPAN

Kenji,

I have the full service manual for the GX-1. If you need them, I can send
you the schematics for the KAS.
I designed a MIDI-enabled replacement KAS. Take a look here:
http://www.sequentix.com/gx1/

I have the two original KAS boards taken from the GX I designed the MIDI
retrofit for.
If you are not interested in adding MIDI, and it turns out you have any
failed (and unobtainable) Yamaha ICs, I could ask the owner if he might sell
them.
I also have a MIDI-enabled Tone Board replacement for solid-state patch
storage and MIDI editing that is just about finished.

Your description of 2 octaves out of 5 being correct suggests a failed 4051,
IC19.
That is the analogue switch that selects the octave reference for the
semitone DAC.

Best regards,
Colin Fraser
Sequentix Music Systems Ltd
http://www.sequentix.com

> -----Original Message-----
> From: yamahacs80@yahoogroups.com
> [mailto:yamahacs80@yahoogroups.com] On Behalf Of kiucd
> Sent: 30 October 2009 18:03
> To: yamahacs80@yahoogroups.com
> Subject: [yamahacs80] Need help on KAS board for GX-1
>
> hello
> I need help for my GX-1.
> both of KAS boards for upper and lower
> keyboards have problem and now my GX-1 can not sound correct.
>
> upper key keeps silence.
> lower key, two octaves out of 5 sound correct, however the
> others sound silence or strange.
>
> YAMAHA here in JAPAN gave up to fix them already and my
> friend in sweden does not have time to help me.
>
> sorry to bother this message board since it is for CS80.
> I hope to hear from some analogue synthe lovers......
>
> sincerely
>
> Kenji
> YOKOHAMA city, JAPAN
>
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>