So all the voltages read the same on both chips except for pin 13 which i make a note of :
1) +13.54 14) +15
2) 0 13) -4.92 (U5 Stepped) +12.64 (U2 Smooth)
3) -9.23 12) +13
4) -14.35 11) -.115
5) +11.13 10) -.112
6) -0.113 9) 0
7) -15 8)-.010
1) +13.54 14) +15
2) 0 13) -4.92 (U5 Stepped) +12.64 (U2 Smooth)
3) -9.23 12) +13
4) -14.35 11) -.115
5) +11.13 10) -.112
6) -0.113 9) 0
7) -15 8)-.010
--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> Seriously, chip frying is indication of serious power routing issues.
>
> With the chips OUT, read the voltages on each pin of the socket, then list
> them here.
>
> Ken
>
> >Thanks again Ken, and Rich for all the helpful suggestions.
> >I've triple checked component values at this point,replaced
> trannies,ic's,gone over continuity testing and visually inspected the board
> under a magnifying lens with no luck.
> >
> >There has to be a short or something that i am just not seeing because i'm
> getting inconsistent results when i plug it in every time i make a change.I
> fried another lm3900 in the smooth section only this time it took a few
> minutes.I've been able to get a slewed/smoothed signal to pass but no
> control over the hold or rate, i've gotten a steady tone from plugging the
> cycle into the in of the smooth section but again no control to change the
> pitch and now i'm back to were i started with no effect and a strong
> negative voltage on the outputs ?
> >
> >I'm gonna take a little break but at this point i'm seriously considering a
> do over.
> >
> >Thanks again guys i really appreciate you taking the time to offer your
> time and experience !
> >
> >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >>
> >> Been thinkng about this - The problem may also be caused by putting a
> >> voltage on the input pins, which are designed for current, not voltage.
> >> Check nothing is shorted to them. Check your resistor values. Maye sure you
> >> haven't installed 15 ohms instead of 1M.
> >>
> >> Ken
> >>
> >> >Will do.Thanks guys!
> >> >I'll report back when i get this working.
> >> >
> >> >--- In cgs_synth@yahoogroups.com, Richarius Molindarius
> >> <richmolindarius@> wrote:
> >> >>
> >> >> Use a well lit magnified lamp. Especially for that board. Hard to find
> >> >> small trace breaks and bad solder joints.
> >> >>
> >> >>
> >> >> [Non-text portions of this message have been removed]
> >> >>
> >> >
> >> >
> >> >
> >> >
> >> >------------------------------------
> >> >
> >> >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/>
>