Texas Instruments.
--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> What manufacturer were the chips?
>
> Ken
>
> >One thing of interest, I bought the LM3900s and they say LM3900 on the
> chips but the package they came in said LM339. But I just figured they used
> containers they had on hand. I'll pick up some other LM3900s and give it a
> shot and I'll do a little research on PN4250s I used.
> >
> >Thanks, Sean
> >
> >--- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >>
> >> Looked it all over. Compared it with mine. Can't see anything obviously
> amiss.
> >> My thoughts:
> >> 1) check that the PN4250 are in the correct way. I can see you have them
> >> according to the overlay, but perhaps the transistors are reversed int he
> >> package. (all the same, I don't see how this would have any effect on your
> >> problem.
> >> 2) I guess it is possible that it is the LM3900 chips themselves that are no
> >> good. If someone has relabeled CA3401 and sold them as LM3900, you would
> >> expect trouble, as the CA3401 is only good to 15V, unlike the LM3900 that
> >> can go up to 30V. They aren't NTE or something like that, are they?
> >> 3)I can't read the 1n caps, so I can't say they are the right part.
> >> (0.001uF, 1n, 1000pF).
> >>
> >> Ken
> >>
> >> >Maybe, slightly better pic of back...
> >> >https://sphotos-a.xx.fbcdn.net/hphotos-ash4/317422_10151631973766807_174487
> >> 4777_n.jpg
> >> >
> >> >
> >> >--- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@> wrote:
> >> >>
> >> >> Hopefully this works? btw, I also had to use two larger 2.2M resistors
> >> in the build. One is pulled in the pic (for troubleshooting)
> >> >>
> >> >> Thanks -Sean
> >> >>
> >> >>
> >> http://groups.yahoo.com/group/cgs_synth/photos/album/1219515935/pic/list?mod
> >> e=tn&order=ordinal&start=1&dir=asc
> >> >>
> >> >> --- In cgs_synth@yahoogroups.com, sasami@ wrote:
> >> >> >
> >> >> > Take some high res photos - IN FOCUS - of both sides so we can look
> at it.
> >> >> > Ken
> >> >> > >Yup, only connected to 1n cap and not using pad T. No shorting
> when chip
> >> >> > is out. Burn mark on pin 9 appeared from first LM3900 going poof. I've
> >> >> > checked solder joints and traces many times over. I can't help but
> think
> >> >> > it's something else.. maybe a weird transistor or cap or mislabel
> resistor
> >> >> > here? btw, same behavior on both LM3900s... extreme heat. Ouch.
> >> >> > >
> >> >> > >--- In cgs_synth@yahoogroups.com, "cg_synth" <sasami@> wrote:
> >> >> > >>
> >> >> > >> pin 9 should be connected only to a 1n capacitor. Pad T is not used.
> >> >> > There should be no current flow through it. Find out what pin 9 of the
> >> >> > socket is short circuited to.
> >> >> > >>
> >> >> > >> --- In cgs_synth@yahoogroups.com, "Sean" <solidratestudios@> wrote:
> >> >> > >> >
> >> >> > >> > Been testing my voltages (with blown LM3900s removed) btw, pin
> 9 is
> >> >> > getting burns on IC socket.
> >> >> > >> >
> >> >> > >> > 1) +7.50
> >> >> > >> > 2) 0
> >> >> > >> > 3) -7.41
> >> >> > >> > 4) -14.01
> >> >> > >> > 5) +3.59
> >> >> > >> > 6) -0.06
> >> >> > >> > 7) -14.87
> >> >> > >> > 8) -0.01
> >> >> > >> > 9) 0
> >> >> > >> > 10) -0.10
> >> >> > >> > 11) -0.06
> >> >> > >> > 12) +8.06
> >> >> > >> > 13) -3.34 (stepped), +5.82 (smooth)
> >> >> > >> > 14) +14.86
> >> >> > >> >
> >> >> > >> > Strange voltages I'm getting.
> >> >> > >> > -Sean
> >> >> > >> >
> >> >> > >> > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
> >> >> > >> > >
> >> >> > >> > > Sorry, that came out as a big garbled mess.
> >> >> > >> > >
> >> >> > >> > >
> >> >> > >> > > 1) +13.54
> >> >> > >> > > 2) 0
> >> >> > >> > > 3) -9.23
> >> >> > >> > > 4) -14.35
> >> >> > >> > > 5) +11.13
> >> >> > >> > > 6) -0.113
> >> >> > >> > > 7) -15
> >> >> > >> > > 8) -.010
> >> >> > >> > > 9) 0
> >> >> > >> > > 10) -.112
> >> >> > >> > > 11) -.115
> >> >> > >> > > 12) +13
> >> >> > >> > > 13) -4.92 (Stepped U5) +12.64 (Smoothed U2)
> >> >> > >> > > 14) +15
> >> >> > >> > >
> >> >> > >> > > --- In cgs_synth@yahoogroups.com, "adematteo" <adematteo@> wrote:
> >> >> > >> > > >
> >> >> > >> > > > 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
> >> >> > >> > > >
> >> >> > >> > > > --- 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/>
> >> >> > >> > > > >
> >> >> > >> > > >
> >> >> > >> > >
> >> >> > >> >
> >> >> > >>
> >> >> > >
> >> >> > >
> >> >> > >
> >> >> > >
> >> >> > >------------------------------------
> >> >> > >
> >> >> > >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/>
> >> >> >
> >> >>
> >> >
> >> >
> >> >
> >> >
> >> >------------------------------------
> >> >
> >> >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/>
> >>
> >
> >
> >
> >
> >------------------------------------
> >
> >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/>
>