Vintage Synth Repair

----- Original Message -----

From: Philip

To: vintagesynthrepair@yahoogroups.com

Sent: Friday, June 06, 2008 9:43 PM

Subject: Re: [vintagesynthrepair] Re: Prophet 10 dead

Well you should have used a 5114 not a 2114, that I'm
pretty sure of, will cause you problems.

A 2114 is not a cmos device, it is an nmos..therefore
they use different currents..a D444 is pretty fast too
12ns or something.

For instance patch memory: a 5114 connected to a 3v
lithium battery will last years..but with 2114 it will
last a few days.

Perhaps others with better knowledge than me on this
subject can explain further?

Phil.

--- Frank Simon <fsimon001@neo.rr.com> wrote:

> I found an Motorola MCM2114P45 from a ebay seller
> for $3. I was hesitant because it was their slowest
> access time part at 450nS. I don't know what the
> D444C access time spec is. I figured it was around
> 200nS but hopefully the 450 is ok.
>
>
> ----- Original Message -----
> From: Philip
> To: vintagesynthrepair@yahoogroups.com
> Sent: Friday, June 06, 2008 8:21 AM
> Subject: Re: [vintagesynthrepair] Re: Prophet 10
> dead
>
>
> Excellent news, well done..so did you use the Ram
> I
> suggested? Or did you find a 444?
>
> Thanks, Phil.
>
> --- fsimon100 <fsimon001@neo.rr.com> wrote:
>
> > I truly had a great day. I replaced a 1Kx4 RAM
> and
> > resolved my
> > computer problem on my P10. Now all LEDs light
> up
> > and the unit
> > behaves somewhat functional. Upon turn on the
> unit
> > goes to tune cycle
> > then all LEDs light up and entire panel is
> > functional. Still no sound
> > but this is a great milestone. Two problems I
> see
> > are sequential
> > board is dead which I think I'm on top of. This
> is
> > PCB9 which I over
> > voltaged when I put the 12V regulator in instead
> of
> > 5V (due to poor
> > documentation this is an option for tape or
> wafer
> > drive). I think
> > this will be easy to fix but I was hoping to
> help on
> > one clue. There
> > is a window showing voices 1 thru 5 and below 6
> thru
> > 10. The top 1
> > thru 5 show 1,3, and 4 LEDs on continously never
> > changing. The bottom
> > 6 thru 10 change as I hit the keys as if it is
> > responding however LED
> > 7 never comes on. Can someone offer advice. I
> have 4
> > CEM3310s out on
> > the top voice board. It is to my understanding I
> may
> > get a noise out
> > if configured right to see functionality before
> I
> > buy expensive chips.
> >
> > Sorry long but I am very happy to be at this
> status.
> > Can sequencer
> > shut down operation. Was curious, should I get
> sound
> > without
> > sequencer.
> >
> >
> >
> > --- In vintagesynthrepair@yahoogroups.com,
> "Frank
> > Simon"
> > <;fsimon001@...> wrote:
> > >
> > > I did find a chip pulling down DB4 on U311 it
> is a
> > 6514 4K CMOS
> > RAM. Thank god for IC sockets. The only problem
> I'm
> > a little confused
> > on a cross for it. It appears obsolete. It is
> called
> > D444C on the
> > chip and 6514 on schematic. Can anyone offer
> advice
> > on a cross.
> > > ----- Original Message -----
> > > From: fsimon100
> > > To: vintagesynthrepair@yahoogroups.com
> > > Sent: Friday, May 30, 2008 8:58 AM
> > > Subject: [vintagesynthrepair] Prophet 10 dead
> > >
> > >
> > > Was curiouse if anyone can offer help. I
> bought
> > a dead P10 no
>; > lights
> > > or anything. The processor is good. I put
> logic
> > analyzer on
> > decoder
> > > output and see ROM1 (Y0) and RAM (Y5)(which I
> > believe is the
> > scratch
> > > pad memory)active at start up. All address
> buses
> > and Data buses
> > are
> > > active. I am not certain the algorithm. A flow
> > chart would be
> > nice or
> > > some help with what I should see at some
> > critical points. I am
> > > wondering if there is a chance the ROMs lost
> > programming and how
> > would
> > > I know. Even if they did shouldn't lights
> and/or
> > display come on.
> > And
> > > yes the power supplies are good.
> > >
> >
> >
> >
>
>
>
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