Vintage Synth Repair

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 
scanner also scans all of 
> the buttons during each cycle.
> 
> For what it's worth (not knowing if it also applies to the P-10), 
to enter the CPU and RAM 
> test on a late rev. Prophet 5, turn off the power, put the record 
switch to "enabled", and 
> jumper test point 304 (MEM TEST) to plus 5V, then turn on. The 
machine starts 
> sequentially flashing it's LED's, to then enter the memory test, 
press TUNE. It runs through 
> 4 tests, counting 1-4 as it does them, and finishes on 0, 
indication no failures. If it stops 
> on 1-4, it is indication a failure of either the scratchpad RAM, 
NV RAM, PROM or 8253 
> timer (1,2,3 and 4).
> 
> I haven't used these tests on a P10, so I don't know if they 
apply, but otherwise maybe the 
> best idea would be to disconnect the sequencer board and just 
start the usual traditional 
> checking of the main CPU lines to see if any of the data or 
address lines are hung.
> 
> 
> --- In vintagesynthrepair@yahoogroups.com, "Frank Simon" 
<fsimon001@> wrote:
> >
> > On Brd 3 there are three EPROMs with the Z80 CPU. The first 
says: 0 TEN 5.0, second 
> says: 1 TEN 5.0, third says: 2 TEN 5.0 on their stickers. 
> > 
> > On Brd 9 there is one EPROM with the Z80 CPU. The sticker on it 
is not too legible what I 
> do see is: SEQ (that part is clear) below it say C1 or C.1 or I 
was thinking maybe 2.1( if 
> upper half of 2 was missing). 
> > 
> > Both Z80s on pin 6 CLK have 2.5MHz clock at about 4v p-p. and 5v 
dc on pin 11. Does 
> the EPROM lose all programming if battery dies? If so how do you 
reload? Will keyboard 
> not boot without EPROM program. My friend today is bringing me a 
Z80 CPU in so I can 
> swap out.
> > 
> > 
> > 
> >   ----- Original Message ----- 
> >   From: thirteentech 
> >   To: vintagesynthrepair@yahoogroups.com 
> >   Sent: Monday, April 28, 2008 7:47 AM
> >   Subject: [vintagesynthrepair] Re: Prophet 10 repair (was Hi 
from a new member).
> > 
> > 
> >   What is written on the stickers on the EPROMS?
> > 
> >   --- In vintagesynthrepair@yahoogroups.com, "Frank Simon" 
<fsimon001@> wrote:
> >   >
> >   > I don't know. How do I find this out.
> >   > ----- Original Message ----- 
> >   > From: Stephen Jones 
> >   > To: vintagesynthrepair@yahoogroups.com 
> >   > Sent: Monday, April 28, 2008 12:14 AM
> >   > Subject: Re: [vintagesynthrepair] Re: Prophet 10 repair (was 
Hi from a new member).
> >   > 
> >   > 
> >   > Which Rev. Processor board do you have? All the Rev.
> >   > 3.1 and 3.2 Prophet 5's have a built in memory test,
> >   > and latest software versions also have a basic CPU
> >   > test. Which software version do you have?
> >   > 
> >   > --- Frank Simon <fsimon001@> wrote:
> >   > 
> >   > > Steve,
> >   > > The TUNE LED does not come on. Since I am four
> >   > > CEM3310s short, should certain slots be populated
> >   > > just to get boot up? All the supplies are up. I am
> >   > > suspicious of PCB9 due to the 12v applied and you
> >   > > mentioned EQ board. There are a couple IC's that are
> >   > > warm on the EQ board but not so hot I can't keep my
> >   > > finger on it. Can you offer a couple key
> >   > > troubleshooting spots for measurements to help me
> >   > > isolate this? I'm assuming I have no way to bless
> >   > > the Processor. All I have is an Oscope, function
> >   > > generator, and multimeter.
> >   > > 
> >   > > 
> >   > > ----- Original Message ----- 
> >   > > From: thirteentech 
> >   > > To: vintagesynthrepair@...m 
> >   > > Sent: Monday, April 21, 2008 12:21 AM
> >   > > Subject: [vintagesynthrepair] Re: Prophet 10
> >   > > repair (was Hi from a new member).
> >   > > 
> >   > > 
> >   > > When you turn the machine on the front panel
> >   > > should be dark with the exception of the 
> >   > > [TUNE] switch. The machine boots into it's
> >   > > autotune mode and suppresses all of the front 
> >   > > panel lights and controls while it does so. it
> >   > > should take 8-10 seconds if the machine is 
> >   > > functional, longer if voices are way out of
> >   > > calibration.
> >   > > 
> >   > > Does the TUNE button LED come on when you power
> >   > > up?
> >   > > 
> >   > > --- In vintagesynthrepair@yahoogroups.com, "Frank
> >   > > Simon" <fsimon001@> wrote:
> >   > > >
> >   > > > Steve,
> >   > > > I have all power supplies in order. There is
> >   > > power to all boards. When I turn it on 
> >   > > shouldn't it boot up and LED's cycle on or blink
> >   > > or even be switchable? The panel is dead. 
> >   > > Does this sound like processor to you?
> >   > > > 
> >   > > > ----- Original Message ----- 
> >   > > > From: thirteentech 
> >   > > > To: vintagesynthrepair@yahoogroups.com 
> >   > > > Sent: Saturday, April 19, 2008 1:07 AM
> >   > > > Subject: [vintagesynthrepair] Re: Prophet 10
> >   > > repair (was Hi from a new member).
> >   > > > 
> >   > > > 
> >   > > > Each of the 5 voices on each voice board has two
> >   > > CEM3310 envelope generators. One 
> >   > > > controls the volume envelope of the voice, and
> >   > > the other controls the filter cutoff of 
> >   > > the 
> >   > > > voice if you bring up the filter envelope
> >   > > modulation control. If the 3310's in the filter 
> >   > > > control line are faulty it should only manifest
> >   > > when you turn on the filter envelope 
> >   > > > modulation. If this is off then the voice should
> >   > > sound if the VCF cutoff pot is set open. 
> >   > > If 
> >   > > > you have bad 3310's in the VCA envelpoe
> >   > > position, the voice won't sound.
> >   > > > 
> >   > > > I am assuming that your P10 has Rev 3.x Prophet
> >   > > 5 voice boards in it, because in the 
> >   > > > Sequential System Technical manual which covers
> >   > > all Prophets from Rev 3.0-3.2, the 
> >   > > > Prophet 10 and the Poly Sequencer, they all use
> >   > > the same basic voice board. So for 
> >   > > > instance, in Voice 1 of the voice board, U412 is
> >   > > the amplifier envelope generator, and 
> >   > > > U417 is the filter envelope generator.
> >   > > > 
> >   > > > --- In vintagesynthrepair@yahoogroups.com,
> >   > > "Frank Simon" <fsimon001@> wrote:
> >   > > > >
> >   > > > > Steve,
> >   > > > > I am pleased to know there is a technique to
> >   > > troube this with the bad ICs. I hope to 
> >   > > get 
> >   > > > to that point soon. If I remember there were no
> >   > > LEDs on control panel lit when turned 
> >   > > on. 
> >   > > > Is there a local spot that isolates that
> >   > > symptom? I haven't removed the top boards yet. 
> >   > > > Hopefully I can handle that. 
> >   > > > > 
> >   > > > > I guess I am confused on VCA and VCF envelope
> >   > > positions. Can you give me a 
> >   > > > explanation of how to determine which state the
> >   > > IC is in.
> >   > > > > Frank
> >   > > > > 
> >   > > > > 
> >   > > > > 
> >   > > > > 
> >   > > > > ----- Original Message ----- 
> >   > > > > From: thirteentech 
> >   > > > > To: vintagesynthrepair@yahoogroups.com 
> >   > > > > Sent: Friday, April 18, 2008 6:04 PM
> >   > > > > Subject: [vintagesynthrepair] Prophet 10
> >   > > repair (was Hi from a new member).
> >   > > > > 
> >   > > > > 
> >   > > > > Well, if you have metered all of the power
> >   > > supply rails in the machine, and are 
> >   > > satisfied 
> >   > > > > that they are all in spec, then go ahead and
> >   > > put the voice boards back in. Remove the 
> >   > > > > known bad 3310's, and if any were in VCA
> >   > > ENVELOPE positions, replace them with 
> >   > > > 3310's 
> >   > > > > from VCF ENVELOPE positions. This will allow
> >   > > you to set up a patch with the VCF 
> >   > > > envelopes 
> >   > > > > control turned off and still have all of the
> >   > > voices audible so that you can hear is all 
> >   > > the 
> >   > > > > voices are working. 
> >   > > > > 
> >   > > > > The EQ board on P10's was another source of
> >   > > problems too of you don't get any 
> >   > > > sound. 
> >   > > > > 
> >   > > > > As for the sequencer board, the best way to
> >   > > test functionality is to get the rest of the 
> >   > > > > machine basically playing and then just try
> >   > > out the sequencer and see if it loads and 
> >   > > > plays 
> >   > > > > back notes.
> >   > > > > 
> >   > > > > Sounds like your power supply lines are the
> >   > > most important issue, so as I mentioned, 
> >   > > > put 
> >   > > > > all your attention on them being correct
> >   > > first. There are lots of CEM3310's in the 
> >   > > > machine, 
> >   > > > > so you can definately get the machine playing
> >   > > without 4 of them, just make sure that 
> >   > > > there 
> >   > > > > are good chips in the VCA envelope positions.
> >   > > > > 
> >   > > > > Steve.
> >   > > > > 
> >   > > > > --- In vintagesynthrepair@yahoogroups.com,
> >   > > "fsimon100" <fsimon001@> wrote:
> >   > > > > >
> >   > > > > > Steve,
> >   > > > > > Thanks, obviously I have a Rev 1. My
> >   > > schematic is a scanned copy and 
> >   > > > > > didn't see the note and still don't but I
> >   > > know you are correct. What 
> >   > > > > > do you think I could have damaged with the
> >   > > 12v I put in? Like I said 
> >   > > > > > U931 shorted and got hot. I know that may be
> >   > > a tough question 
> >   > > > > > without personally probing but the board is
> >   > > holding the 5v now. How 
> >   > > > > > could I verify functionality of PCB9. 
> >   > > > > > 
> >   > > > > > Also if I put one of the voice boards in
> >   > > with 4 CEM3310 missing can 
> >   > > > > > I continue troubleshooting? Is there a
> >   > > chance I could get confidence 
> >   > > > > > from a oscope or panel lights before I buy
> >   > > four CEMs.
> >   > > > > > 
> >   > > > > > --- In vintagesynthrepair@yahoogroups.com,
> >   > > "thirteentech" 
> >   > > > > > <thirteentech@> wrote:
> >   > > > > > >
> >   > > > > > > The Prophet 10 service manual shows that
> >   > > U603 is a +5V for rev. 1 
> >   > > > > > machines, or +12V for Rev. 0 machines. It
> >   > > looks like that supply is 
> >   > > > > > for either a 5V 
> >   > > > > > > cassette drive or a 12V wafer drive
> >   > > depending on which version of 
> >   > > > > > machine you have, but the schematic also
> >   > > shows a note on the 5.6V 
> >   > > > > > rail of the PSU 
> >   > > > > > > saying: "To PCB 9, Rev 0, not used for Rev
> >   > > 1". So depending on 
> >   > > > > > whether you have a Rev 0 or Rev 1, there
> >   > > will be different supplies 
> >   > > > > > on P603 pins 2 and 
> >   > > > > > > 3.
> >   > > > > > > 
> >   > > > > > > 
> >   > > > > > > --- In vintagesynthrepair@yahoogroups.com,
> >   > > "Frank Simon" 
> >   > > > > > <fsimon001@> wrote:
> >   > > > > > > >
> >   > > > > > > > Hi Steve,
> >   > > > > > > > I have a manual I downloaded from
> >   > > paintingwithsound.com. It is 
> >   > > > > > hard to read. I was a little disappointed
> >   > > when 
> >   > === message truncated ===
> >   > 
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