Hi,
I've done a bit of testing and looking around the sequencer and I
found a number of faults (in design and build) that I have rectified.
I've checked that I'm putting +15V, 0V and -15V (actually +14.8V
and -15.2V...is this significant? That fault lies with my power
supply) I've tested the Sequential switch and that is working OK. I
now find that the sequencer of stuck on step 3 and but the step LED
only shows when I select one of the trigger output switches (these are
all driven from the PULSE OUT output. Diodes take the pulse away
through a number of switches, and onto trigger buses. Each of these
buses appears to be working correctly. Flicking each switch results
in the LED flashing and a Trigger pulse appearing at the relevant
output socket). On reflection, this is probable cause by the LED
running to GND through the trigger switches, and I probably need to
wire it to GND via a resistor (prob 1K5).
I've double checked that all the ICs are the correct ones and are in
the right way round and that the J, G and H are wired up according to
the website. I've inspected each 'A' board and I can't see any
problems, although I did take a few liberties by not wiring up the
Push Button, the AEP and the CPO. Instead, I have a clock input going
to a two way switch (centre off) giving a STOP, FORWARD and BACK
position, this being wired directly to the UP and DOWN inputs of the
'B' board. I also have a manual push button running from +15V to the
UP input, and push buttons running from +15V to the EXT PULSE input of
the 1st and 16th steps, the idea being that I could reset to these
steps at the touch of a button. None of these buttons work.
Also of significance is that there is the same output from each Row,
but that this is not affected by moving any of the knobs. This is
about 50mV.
I reckon from the symptoms above, the my trigger switches are fine
as is my Seq Switch. I assume that the problem lies in the 'B' board
since inputs to the UP and DOWN are not working and every single knob
doesn't seem to work (at least the 4 of step 3). I did make a bit of a
mess of the 'B'board as I wired it up, then had to remove it, but I
thought I had patched it up.
I know it is a bit of a black art trying to diagnose these things in
person, much less by remote but I'd really appreciate some help, here
as I'm running out of ideas.
Thanks in advance
Stuadh
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--- In cgs_synth@yahoogroups.com, "stuadh" <stuadh@...> wrote:
>
> Hi,
>
> After a LOT of work, I've just plugged in my Programmer/Sequencer
> and it doesn't work. At least there was no smoke or burning smells.
> But it realy isn't looking healthy. Although it is too late at the
> moment to describe the symptoms in detail, it doesn't advance along
> the stages. If you add a clock, some of the LEDs flash on and off.
>
> 1. What do I do now?
>
> 2. Because I made a number of changes to Ken's module, can anyone
> recommend any (free) software for Mac OSX that can be used to draw
> circuits? That way someone might be able to tell me if it is an
> inherent design flaw.
>
> Many thanks
>
> Stuadh
>