If you look at the datasheet for the 7408 you will see that pin 7 is the GND pin and thus should always be connected to ground.
In practice, this means pins 7 of ICs 30 and 31 are connected, yes, but only because they're both connected to ground.
Note: I guess the schematics are wrong again as they've marked pin 1 of IC30 as being grounded, while pin 1 is connected between IC31-30, and pin 1 is connected to +5V on IC31 = shortcircuit between +5VDC and GND :/
So that's another error in the schematics.
If you're really a novice, I would suggest handing your unit over to someone with a bit more knowledge as you can easily make things worse by using this synth as a learning testbed :) No offense, but if you don't know your way around schematics and logic circuits, please let someone else look at it.
Oh, and I'm in Sweden.
Greetings :)
BR,
Peter
----- Original Message -----
From: tonezone020
To: PolySix@yahoogroups.com
Sent: Tuesday, July 24, 2012 9:42 PM
Subject: [PolySix] Re: Polysix contact strip
Hi again,
Should IC31 and IC30 pins 7 be connected to each other ? Also, should pin 1 from both run to ground ?
As you can tell, I'm a complete novice trying to make sure about reading the schematics !
I'm in the UK by the way. Where are you ?
Regards,
Tony
--- In PolySix@yahoogroups.com, "tonezone020" <swamp.gigs@...> wrote:
>
> Hi Peter,
>
> I bridged IC26 pin 5 --> IC34 pin 5 and there's continuity to IC22 pin 11 , however doing so knocked out the Bank A thru to Write switches and when the I change patch switches, the sound played doesn't.
>
> Any pointers to where to look ?
>
> Thanks
>
> Tone
>
>
> --- In PolySix@yahoogroups.com, Peter Mörck <peterm@> wrote:
> >
> > Hi,
> >
> > Regarding IC26 pin 5 --> IC34 pin 5:
> >
> > Yes, they should be connected to eachother.
> > But more importantly, do any of them have contact with pin 11 of the 8048 (IC22) ?
> > IC26 and IC34 are latches, controlled by pin 11 of the 8048.
> > The fact that IC26 and IC34 have pins 5 connected to eachother doesn't necessarily mean any of them will work, unless they in turn are connected to the 8048 pin 11.
> > So connection between IC22 pin 11 <--> IC26 pin 5 <--> IC34 pin 5 is what you need.
> >
> > BR,
> > Peter
> >
> >
> >
> > ----- Original Message -----
> > From: tonezone020
> > To: PolySix@yahoogroups.com
> > Sent: Tuesday, July 24, 2012 11:59 AM
> > Subject: [PolySix] Re: Polysix contact strip
> >
> >
> >
> > Erm,
> >
> > Correction - that should be IC24 p2, 1, 11, 10 that is connected to IC32 p2, 1, 17, 16
> >
> > Cheers,
> >
> > Tony
> >
> > --- In PolySix@yahoogroups.com, "tonezone020" <swamp.gigs@> wrote:
> > >
> > > Hi Don and Peter,
> > >
> > > Your messages have been very helpful consequently I've discovered anomalies elsewhere...
> > >
> > > IC26 p5 doesn't connect to IC34 p5 - should I bridge this ?
> > >
> > > IC26 to IC32 connections are all fine.
> > >
> > > Also I think there's a mistake in the schematics. Rather than IC34 connecting to IC32 it seems to be IC26 p2, 1, 11, 10 that is connected to IC32 p2, 1, 17, 16
> > >
> > > Regards,
> > >
> > > Tony
> > >
> > >
> > > --- In PolySix@yahoogroups.com, "backshall1" <backshall1@> wrote:
> > > >
> > > > Yes, there is an error in the schematics. Pin 5 is +5v, not pin 4. Pin 4
> > > > really does go to pin 12 on the 8048. I just checked a clone board and an
> > > > old original KLM-367. They are the same.
> > > >
> > > > Don B.
> > > >
> > > >
> > > >
> > > > _____
> > > >
> > > > From: PolySix@yahoogroups.com [mailto:PolySix@yahoogroups.com] On Behalf Of
> > > > Peter Mörck
> > > > Sent: Monday, July 23, 2012 8:25 PM
> > > > To: PolySix@yahoogroups.com
> > > > Subject: Re: [PolySix] Re: Polysix contact strip
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > You must be looking at the board layout drawing.
> > > > The schematics are different and have no "layers". They just show how it's
> > > > connected without actual physical constraints.
> > > >
> > > > Anyway, I just looked and pins 1,4,10,13,14 of IC31 are tied to +5V :)
> > > >
> > > > By the way,
> > > > I assume there's an error in the schematics indicating pin 4 tied to pin12
> > > > of the 8048, as it's also tied to +5V.
> > > > Either that's pin 5 instead, or vice versa.
> > > >
> > > > IC31 is just a quad AND gate acting as a buffer. Each of the AND gates has
> > > > one of its inputs tied to +5V so whatever appeard on the other input will
> > > > also appear on the output of that gate.
> > > >
> > > > The traces under IC31 are usually attacked by the battery acid though and it
> > > > is good if you do continuity testing around that area.
> > > >
> > > > BR,
> > > > Peter
> > > >
> > > > ----- Original Message -----
> > > > From: tonezone020
> > > > To: PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com>
> > > > Sent: Tuesday, July 24, 2012 1:45 AM
> > > > Subject: [PolySix] Re: Polysix contact strip
> > > >
> > > > Hi,
> > > >
> > > > Looking at the schematics it's hard to tell - it doesn't seem like there is
> > > > one for the underside of the board ...
> > > >
> > > > Regards,
> > > >
> > > > Tony
> > > >
> > > > --- In PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com> , Peter
> > > > Mörck <peterm@> wrote:
> > > > >
> > > > > Just compare with the schematics?
> > > > >
> > > > > BR,
> > > > > Peter
> > > > >
> > > > > ----- Original Message -----
> > > > > From: tonezone020
> > > > > To: PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com>
> > > > > Sent: Tuesday, July 24, 2012 12:52 AM
> > > > > Subject: [PolySix] Re: Polysix contact strip
> > > > >
> > > > >
> > > > >
> > > > > Hi,
> > > > >
> > > > > Thanks for your message.
> > > > >
> > > > > I managed to sort the strips out - they had stretched, but with a bit of
> > > > coaxing the keys are now working.
> > > > >
> > > > > Been slowly trying to fix the battery leak problem with a tiny bit of
> > > > success and Old Crow's advice from his site.
> > > > >
> > > > > I discovered pin numbers 13 and 14 on IC31 are connected. Do you know if
> > > > this should be so? There seems to be a copper trace on the underneath
> > > > circuitry. It also appears to be the same for IC30...
> > > > >
> > > > > Thanks,
> > > > >
> > > > > Tony
> > > > >
> > > > > --- In PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com> ,
> > > > bastebraak <bastebraak@> wrote:
> > > > > >
> > > > > >
> > > > > >
> > > > > > Is the old one damaged or just not working well. I fixed the contacts on
> > > > my polysix with a paste i ordered online.
> > > > > >
> > > > > >
> > > > > > Verzonden vanaf Samsung Mobiletonezone020 <swamp.gigs@> schreef:
> > > > > > Hi All,
> > > > > >
> > > > > > Does anyone know where I can get a couple of 6 bubble contact strips or
> > > > alternatives for my synth, preferably in the Uk ?
> > > > > >
> > > > > > Many thanks in advance,
> > > > > >
> > > > > > Tony
> > > > > >
> > > > > >
> > > > > >
> > > > > > ------------------------------------
> > > > > >
> > > > > > Yahoo! Groups Links
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > [Non-text portions of this message have been removed]
> > > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
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> > > >
> > > > [Non-text portions of this message have been removed]
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> >
>
[Non-text portions of this message have been removed]Message
Re: [PolySix] Re: Polysix contact strip
2012-07-24 by Peter Mörck