--- In cgs_synth@yahoogroups.com, sasami@... wrote:
I tried looking at the CPO under a scope and it was still very very low pulse output, but there IS a pulse making its way through. (still around 100mv)
>Yes the silkscreen on this board does list 470k instead of 47k, as well i noticed it in red on the board layout on the project page so it definitely has a 470k resistor in there. I also just gone done removing and testing the part to make sure it was indeed 470k so we are good there.
> >When i measure the output of CPO it goes from 111mv to 201mv when the
> button is pushed which is obviously not high enough to trigger anything.
> >Any suggestions on what areas to check in the CPO circuit would be much
> appreciated :0
>
> A meter won't help because it only PULSES. The pulse is very short.
> None the less:
> All Type B boards that do not have a revision number have an error.
> Physically between the two BC557s on the PCB is a 47k resistor. This should
> be 470k, and will solve problems some of you are having with the common
> pulse out.
> I do not think you have that version of the board though. I expect you have
> a ver1.1
>
I tried looking at the CPO under a scope and it was still very very low pulse output, but there IS a pulse making its way through. (still around 100mv)
> AEP gives a pulse out every time the sequence moves, whatever the reason, beokay this is just stays high @4.64v no matter what i do.
> it button, or clock or preset input.
>
> Ken
>
> >It was a big pain to swap these out after everything was mounted and wired
> but i did it and now all the buttony-buttons work.
> >
> >Now to try to figure out why CPO and AEP doesnt work.
> >I'll focus on CPO for now since i'm not really sure what AEP is supposed to
> do. (i'll do some reading on this later once i have CPO working)
> >I have gone through the schematic and traced all part values and everything
> appears to be correct, but its also possible that ive missed something.
> >When a button is pushed the A bus goes high to 6.20v and the stage selects
> correctly.
> >When i measure the output of CPO it goes from 111mv to 201mv when the
> button is pushed which is obviously not high enough to trigger anything.
> >Any suggestions on what areas to check in the CPO circuit would be much
> appreciated :0
> >
> >
> >
> >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >>
> >>
> >> 47k, 150k, 470k, 820R 680R
> >>
> >> Cheers,
> >> Ken
> >>
> >> Ken
> >>
> >> >> As i mentioned earlier in the thread this is the old style boards (non
> >> RoHS), Just wondering at this point if there is a component value that might
> >> be incorrect on all 8 stage boards.
> >> >>
> >> >
> >> >okay, had an even closer look and i noticed that H was only going up to
> >> 6.7v when pressing the button so i figured this might have something to do
> >> with resistor values.
> >> >I went back over the boards and i noticed a discrepency between the
> >> silkscreen rev A and the picture of the rev b boards on the CGS site.
> >> >The row of resistors closest to the LED and diode on my board are (in order
> >> of closest to farthest (47k,47k,470k,820r,680r) and the CGS site with the
> >> revB boards (47k,150k,470k,820r,680r)
> >> >
> >> >Now to further complicate things i was following the values listed on the
> >> website, BUT i got the 47k and 150k REVERSED which probably explains the
> >> voltage drop.
> >> >My question here is, Which should i follow for these REV A (non RoHS)
> >> boards. 47k, 47k, or 47k, 150k?
> >> >
> >> >
> >> >
> >> >
> >> >------------------------------------
> >> >
> >> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >> >Yahoo! Groups Links
> >> >
> >> >
> >> >
> >> >
> >> _______________________________________________________________________
> >> Ken Stone sasami@ otherunicorn@
> >> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> >> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
> >>
> >
> >
> >
> >
> >------------------------------------
> >
> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >Yahoo! Groups Links
> >
> >
> >
> >
> _______________________________________________________________________
> Ken Stone sasami@... otherunicorn@...
> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>