Nothing happens. It plays, but the width or pwm does not change. I
have a multimeter, how do i check this stuff out? I dont know a whole
lot about ICs.
--- In PolySix@yahoogroups.com, The Old Crow <oldcrow@o...> wrote:
>
> First thing to do is set VCO to PW and move the width knob from 0
to 10
> and back to 0 and listen to see if it changes accordingly. Then
set it to
> 10 and change the VCO mode to PWM and move the PWM speed knob from
0 to 10
> slowly and note if the cyclic modulation is audible.
>
> If nothing is working then I would imagine either IC20 (LM13600)
needs
> replaced, or the analog switch section IC1C died and IC1 needs
replaced,
> or perhaps the control voltages off deMUX IC19 aren't getting there
and
> IC19, IC12 or IC13 is to blame (least likely though).
>
> Use my schematic as it is much easier to read than the old
service
> manual copy. PWM circuit is on the far right, about 2/3 of the way
down.
> It is marked "PWM MG":
>
>
http://www.oldcrows.net/~oldcrow/synth/korg/polysix/crowlm367/klm367a_
eagle_schem.gif
>
>
> Hope this helps,
>
> Crow
> /∗∗/
>
> On Wed, 31 Dec 2003, ciscomanvann wrote:
>
> > I know this sounds stupid, but how can i tell if the PWM is
working?
> > If it is not, where do I start looking to fix it?
> > Thanks!