Vintage Synth Repair

Your manual question has been discussed on another
synth mailing list. You need the exact version
schematics for your synth, the more info the better.
From Mark Glinsky who has the manual manor site: 

> For performing service on the Sequential Circuits
Prophet 10, is it  
> true that
> one needs the Prophet 5 Rev. 3.3 Service Manual in
conjunction with  
> the
> Prophet 10 Service addendum, which includes the
information for the  
> P10
> unique circuitry?

It's true - though not necessarily the 3.3 version.
The P-10 manual  
only has the non-P-5 stuff in it, so if you want to
troubleshoot the  
voice boards, you have to have the P-5 manual handy.



--- Frank Simon <fsimon001@...> wrote:

> Steve,
> I got this from someone on the Web. Do you feel I
> need what he is selling?
> This is his pitch:
> [From what I've been told now, it seems you need the
> Rev. 3.3 
> Service manual, plus the P10 addendum.
> 
> I can provide the PDF files for the P5 Rev. 3.3
> service manual
> and the P10 Service Addendum on my website for you
> to download for a 
> total of $ 20.]
> 
> 
> 
>   ----- Original Message ----- 
>   From: thirteentech 
>   To: vintagesynthrepair@yahoogroups.com 
>   Sent: Wednesday, April 30, 2008 10:38 PM
>   Subject: [vintagesynthrepair] Re: Prophet 10
> repair (was Hi from a new member).
> 
> 
>   It sounds like you know what you're doing, the
> only way to test the EPROM's (apart from 
>   hung data or address lines) is to replace them.
> Have a look on some of the Prophet 
>   websites to see if anyone has posted the EPROM
> images, but first eliminate everything 
>   else by thorough faultfinding procedures.
> 
>   --- In vintagesynthrepair@yahoogroups.com, "Frank
> Simon" <fsimon001@...> wrote:
>   >
>   > Steve,
>   > Since I downloaded the P5 service manual (it
> only goes to rev 3.2) I have a much better 
>   understanding of the system. It helps to have a
> good service manual. Before all I had was a 
>   schematic only of the P10. I do have an Oscope and
> I may borrow a logic analyzer. I have 
>   good troubleshooting skills. I have little
> microprocessor troubleshooting but as long as I 
>   understand the flow, I know address and data bus
> and when a part of the system is 
>   Computer Select from a Memory Address Decoder
> A10-A12 to take Adress from CPU to 
>   output data to Data Bus. So I am going to probe
> the tune section (since you said that is 
>   first operation) look for CS to the timer and
> status output then work towards the EPROM if 
>   it gets CS. I think I will put a wire on CPU reset
> to ground instead of cycling power switch. 
>   > 
>   > In general I need to know sequence of events but
> isn't that from firmware programmed 
>   in the EPROM. That is where I need help. How do I
> know it is programmed properly.
>   > 
>   > ----- Original Message ----- 
>   > From: thirteentech 
>   > To: vintagesynthrepair@yahoogroups.com 
>   > Sent: Wednesday, April 30, 2008 6:06 PM
>   > Subject: [vintagesynthrepair] Re: Prophet 10
> repair (was Hi from a new member).
>   > 
>   > 
>   > Yes, it sounds like your computer is not
> running, and you are getting random LED's 
>   when 
>   > you power up. Do you have an oscilloscope and
> any experience troubleshooting 
>   > microprocessors? If not, you will need someone
> who can I think.
>   > 
>   > --- In vintagesynthrepair@yahoogroups.com,
> "fsimon100" <fsimon001@> wrote:
>   > >
>   > > Steve,
>   > > I down loaded a P5 service manual. It is very
> helpful and much 
>   > > better print than the P10 schematic I have. I
> can now see the what 
>   > > you meant by the subtractive synthesis gated
> by the CEM3310. I just 
>   > > need to isolate why the control panel is dead.
> I have two LEDs light 
>   > > up when I power up but not everytime I power
> up. I know the CPU is 
>   > > good now. I'm thinking it has to be on the
> computer system and not 
>   > > the Analog or synth section. Would you agree.
> Thanks for your help 
>   > > and patience
>   > > 
>   > > 
>   > > --- In vintagesynthrepair@yahoogroups.com,
> "thirteentech" 
>   > > <thirteentech@> wrote:
>   > > >
>   > > > Well, I can't guarantee that the machine
> will run OK without the 
>   > > sequencer, but it probably will, and is 
>   > > > worth a try. I see one P10 for every dozen
> P5's that I service, so 
>   > > unfortunately I don't have a P10 in the 
>   > > > shop to look at directly. 
>   > > > 
>   > > > As for service manuals, Sequential put out a
> large folder called 
>   > > the "Prophet Synthesizer and 
>   > > > Polyphonic Sequencer System Technical
> Manual" which has the 
>   > > Prophet 5 REV 3.0, 3.1 and 3.2 service, 
>   > > > programming guide and schematics, the
> Prophet 10 theory, 
>   > > schematics and parts list, and the Poly 
>   > > > Sequencer theory and schematics, the Prophet
> 5 remote service and 
>   > > schematics, and update mod info 
>   > > > for the Rev 3.3 update. much of the P10
> section refers to the P5 
>   > > schematics.
>   > > > 
>   > > > The basic differences between a P10 and a
> Rev 3.x P5 are: The 
>   > > P10's master tune is digitized whereas 
>   > > > the P5's is connected directly to the common
> analog circuit. The 
>   > > P10 also has 6k of PROM compared to 
>   > > > the P5's 2k to allow it to scan the keys and
> controls better to 
>   > > keep scanning delays down to a 
>   > > > maximum of 11ms. 
>   > > > 
>   > > > So if the machine is frozen, the best thing
> to do is to just start 
>   > > making sure that every CPU line looks 
>   > > > like it is doing the right thing, and then
> move on to each device 
>   > > on the data bus and see if it's chip 
>   > > > select input is working. If it is and you
> have gone through all of 
>   > > the basic troubleshooting that you 
>   > > > would expect to do with a microprocessor
> circuit, and it all seems 
>   > > to be running, then take a look a 
>   > > > the autotune circuitry, although this is
> unlikely as your TUNE led 
>   > > is not coming on.
>   > > > 
>   > > > 
>   > > > --- In vintagesynthrepair@yahoogroups.com,
> "fsimon100" 
>   > > <fsimon001@> wrote:
>   > > > >
>   > > > > Steve,
>   > > > > Thanks. Are these diagnostics tribal
> knowledge or are they 
>   > > > > documented in a manual. I do not hve the
> P10 manual. If I find 
>   > > one 
>   > > > > will it give me diags. 
>   > > > > 
>   > > > > I have disconnected the Seq board so
> obviously your saying it 
>   > > will 
>   > > > > run without it. Great. One system removed.
> I do have a z80 CPU 
>   > > to 
>   > > > > swap out. 
>   > > > > 
>   > > > > I was thinking the record switch was a
> microswitch so to enable 
>   > > > > would be a pull down or pull up Res on
> PCB.
>   > > > > 
>   > > > > --- In vintagesynthrepair@yahoogroups.com,
> "thirteentech" 
>   > > > > <thirteentech@> wrote:
>   > > > > >
>   > > > > > I am not certain what the P10's last OS
> revision was, the 
>   > > highest 
>   > > > > that I have seen on a 
>   > > > > > Prophet 5 is V9.3. Looking at the
> schematics of the 2 machines 
>   > > the 
>   > > > > CPU board is similar, 
>   > > > > > they do have different EPROM and NV RAM
> chips. Also the P 10 
>   > > has 
>   > > > > different scanning 
>   > > > > > circuitry because it would have an
> unacceptable scan delay 
>   > > with 2 
>   > > > > keyboards as opposed 
>   > > > > > to the P5's 1 keyboard, which has a
> maximum delay of 10 Ms. 
>   > > The 
> 
=== message truncated ===



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