Tom,
Given that this is a CS 60 there are no TSB or TKC boards.
I will swap out that IC12 on the KAS and see if the issue remains.
INverting voltage on that type of CMOS is indicative of failure (maybe
due to static or something else while changing those caps) - this
1970s CMOS is pretty terrible.
I have already tested all of the wiring and it all seems OK.
Thanks,
Andrew
On 16/07/2011, at 9:28 AM, Quazimodo wrote:
> Hi Andrew,
>
> The only time I ever had anything similar to this was a fault
> affecting mainly the after touch - but also, I seem to remember
> there were actual ∗note∗ issues. The fault in my case was around one
> of the TSB boards. I turned out to be one broken wire! What I would
> do in the first instance is play those high notes that are the
> problem - whilst gently moving the wires going to the boards - TSB,
> TKC and KAS.
>
> Have you been handling any of these boards repeatedly? Turning them
> to and fro during re-capping for example can I would guess, cause
> problems.
>
> Cheers
> TOM
>
> --- In yamahacs80@yahoogroups.com, Andrew Kirkby <kirkbyte@...> wrote:
> >
> > ok,
> >
> > So, all keys up until the top D key work fine. If i press a single
> key
> > above top D i get no sound whatsoever BUT if i hold a key below the
> > top D key and one above at the same time it will produce the note
> > below top D correctly and the note above with lots of distortion and
> > the wrong pitch.
> >
> > If i press 8 keys located below the top D key, all voices work
> fine so
> > i know it's not an issue with a M board.
> >
> > I have checked the ICs on the lower boards and have found some
> strange
> > behaviour on IC12 of the KAS board (4016). If i measure the voltage
> > between ground and pins 8 or 9 while pressing a low key on the
> > keyboard, i get a small voltage (1-3 volts) on the meter. If i
> press a
> > key above that D key i get a negative voltage around -4.5 volts. No
> > lower key press gives a negative voltage.
> >
> >
> > Andrew
> >
> >
> > On 16/07/2011, at 5:19 AM, Quazimodo wrote:
> >
> > > That don't make sense... can you explain it better Andrew..!
> > >
> > > "...unless a key from an octave below it" ...?
> > >
> > > --- In yamahacs80@yahoogroups.com, Andrew Kirkby <kirkbyte@>
> wrote:
> > > >
> > > > I now have another problem on the top octave now - i can't get
> any
> > > > sound unless a key from an octave below it, then i get crazy
> sounds
> > > > without correct pitch. Looks like a morning on the scope is
> > > needed :)
> > > >
> > > > AK
> > > >
> > >
> > >
> > >
> >
> > Andrew Kirkby
> > (e) kirkbyte@...
> > (m) 0416 000 070
> >
> >
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>
Andrew Kirkby
(e) kirkbyte@...
(m) 0416 000 070
[Non-text portions of this message have been removed]