Tech: Seeburg Power Supply Board Revs?

Hi all,

I am working on a Seeburg STD-3 that I recently acquired. I ordered the
manuals (all three of 'em) for the STD-3 from Victory Glass. (Very nice
manuals, btw.) I'm troubleshooting the power supply board, as I have no
-27VDC. When I use an ohmmeter between the -27 test point and the
chassis ground, sure enough I see a short.

I ordered the manuals so I could use the schematics for guidance in the
-27V circuit. The darn power supply board is wired up like a Christmas
tree! (OK, maybe I'm exaggerating a little, but someone did a few hacks
with some wire jumpers and diodes.) I look at the schematics and I
notice that Q3120 (Q20) is part of the -27 circuit. I look at my power
supply board (3112) and there isn't a Q20! I thought that maybe it was
removed, but there isn't a screened mark for Q20. In fact, the -27
circuit on the power supply board I have is different in minor ways than
the schematic!

My power supply board is marked as 31125-1. Is it possible I have a
different board revision than what's in my Victory Glass schematics?
Does the 5-1 denote a version? Or did someone pull a power supply from
a similar Seeburg model and pop it in back in the 1980s? :-)
Unfortunately, I can't proceed troubleshooting until I have a proper
schematic. Any help would be appreciated! Thanks.

Tony
http://girasoli.org/arcade/

On Wed, 08 Aug 2007 22:00:27 -0400, Tron
wrote:

Hi all,

I am working on a Seeburg STD-3 that I recently acquired. I ordered the
manuals (all three of 'em) for the STD-3 from Victory Glass. (Very nice
manuals, btw.) I'm troubleshooting the power supply board, as I have no
-27VDC. When I use an ohmmeter between the -27 test point and the
chassis ground, sure enough I see a short.

I ordered the manuals so I could use the schematics for guidance in the
-27V circuit. The darn power supply board is wired up like a Christmas
tree! (OK, maybe I'm exaggerating a little, but someone did a few hacks
with some wire jumpers and diodes.) I look at the schematics and I
notice that Q3120 (Q20) is part of the -27 circuit. I look at my power
supply board (3112) and there isn't a Q20! I thought that maybe it was
removed, but there isn't a screened mark for Q20. In fact, the -27
circuit on the power supply board I have is different in minor ways than
the schematic!

My power supply board is marked as 31125-1. Is it possible I have a
different board revision than what's in my Victory Glass schematics?
Does the 5-1 denote a version? Or did someone pull a power supply from
a similar Seeburg model and pop it in back in the 1980s? :-)
Unfortunately, I can't proceed troubleshooting until I have a proper
schematic. Any help would be appreciated! Thanks.

Tony

The 31125-1 version does not use Q3120. You should convert your board
to match the Vctory Glass schematics, which are more current. For the
later boards, the design was changed so that the -27 VDC supply
follows the -13 VDC supply. For the -1 board, this was not the case.
The board you have was originally used in the DCC1, which was original
equipment with the LS3. You should consider getting a copy of my
'Seeburg Black and Gray Boxes', avialable from
http://home.pacbell.net/fmillera/books.htm


Cheers,

Tony Miller

Hi Tony,

Thanks for your quick followup!

Upon closer inspection, you are right, of course. I have a DCC1 in
there (along with a SHP1 amp). Maybe someone swapped out the original
DCC and SHP chassis and replaced them with the DCC1 and SHP1 that I
currently have.

To convert my 31125-1 board to match the Victory glass schematics, I
guess that means I need to redo the -13V and -27V circuits. Does your
Black and Gray boxes book instruct on how to modify my 31125-1 power
supply board? If so, I will definitely order it.

Are there buffer board and scan control board differences between the
DCC1 and DCC4? (I'm assuming the DCC4 was standard based on the STD3
book that I have.) I'm just wondering if I should find a DCC4 to put in
there so the Victory Glass DCC schematics I purchased are valid.

Thanks for your help!

Best,
Tony


The 31125-1 version does not use Q3120. You should convert your board
to match the Vctory Glass schematics, which are more current. For the
later boards, the design was changed so that the -27 VDC supply
follows the -13 VDC supply. For the -1 board, this was not the case.
The board you have was originally used in the DCC1, which was original
equipment with the LS3. You should consider getting a copy of my
'Seeburg Black and Gray Boxes', avialable from
http://home.pacbell.net/fmillera/books.htm


Cheers,

Tony Miller

On Wed, 08 Aug 2007 22:53:17 -0400, Tron
wrote:

Hi Tony,

Thanks for your quick followup!

Upon closer inspection, you are right, of course. I have a DCC1 in
there (along with a SHP1 amp). Maybe someone swapped out the original
DCC and SHP chassis and replaced them with the DCC1 and SHP1 that I
currently have.

To convert my 31125-1 board to match the Victory glass schematics, I
guess that means I need to redo the -13V and -27V circuits. Does your
Black and Gray boxes book instruct on how to modify my 31125-1 power
supply board? If so, I will definitely order it.


It does not give directions on how to modify, but does give schematics
for both.

Are there buffer board and scan control board differences between the
DCC1 and DCC4? (I'm assuming the DCC4 was standard based on the STD3
book that I have.) I'm just wondering if I should find a DCC4 to put in
there so the Victory Glass DCC schematics I purchased are valid.

Some resistor value changes and additions to the buffer board. They
are listed. The scan start board remained unchanged.

Cheers,

Tony Miller


Thanks for your help!

Best,
Tony


The 31125-1 version does not use Q3120. You should convert your board
to match the Vctory Glass schematics, which are more current. For the
later boards, the design was changed so that the -27 VDC supply
follows the -13 VDC supply. For the -1 board, this was not the case.
The board you have was originally used in the DCC1, which was original
equipment with the LS3. You should consider getting a copy of my
'Seeburg Black and Gray Boxes', avialable from
http://home.pacbell.net/fmillera/books.htm


Cheers,

Tony Miller

I dont quite understand why one would need to change the circuits around
if the machine was working with the circuits it has now and buying books
on black boxes will remove the short from his power supply .

For the untrained it may be hard to explain how and where to start
testing parts to find the short .

Before you buy books on black and gray boxes take the boxes out and take
the covers off of them . The most common problems with those was bad
solder connections on the tall rows of pins . Resolder all of them with
fresh solder .
If someone got careless with the ``record playing`` lightbulbs and put
in the wrong bulbs or shorted across their sockets it can short
transistor-s in the black box again another hard to explain to the
untrained at this .

Good havens the guy is going to spend more on books than the machine is
worth

On Sat, 11 Aug 2007 00:03:14 -0600, (Ken G.) wrote:

I dont quite understand why one would need to change the circuits around
if the machine was working with the circuits it has now and buying books
on black boxes will remove the short from his power supply .

For the untrained it may be hard to explain how and where to start
testing parts to find the short .

Before you buy books on black and gray boxes take the boxes out and take
the covers off of them . The most common problems with those was bad
solder connections on the tall rows of pins . Resolder all of them with
fresh solder .
If someone got careless with the ``record playing`` lightbulbs and put
in the wrong bulbs or shorted across their sockets it can short
transistor-s in the black box again another hard to explain to the
untrained at this .

Good havens the guy is going to spend more on books than the machine is
worth

The circuits were redesigned because the -13 and -27 VDC power
supplies need to track. As originally designed, one could increase
while the other decreased due to component aging. With the revised
design, the -13 was developed from the -27, so whatever the -27 did,
the -13 followed.

If you want to destroy the customs, go ahead and resolder. They were
correctly wave soldered at the factory, and it is doubtful any of the
chips need to be resoldered. What would cause them to become
unsoldered? Flexing the PC board can crack traces. An uncareful
disassembly of the black box can easily casue this.

You are correct, howver in that replacing a bulb with an incorrect one
can easily destroy the driving transistor inside the black box. Be
careful to only replace bulbs with the correct ones, as documented in
the manual.

Cheers,

Tony Miller

having a machine that runs this DCC originally it had a DCC 1 somewhere
down the line it was changed out to a latter model which are
interchangeable (so are the amps) Am I right Tony m? it is worth getting
tonys books on the black and grey boxes and the shp amp great reading
gives more incite to the beginner than the manual alone

Jim W

"Tony Miller" wrote in message
...
On Sat, 11 Aug 2007 00:03:14 -0600, (Ken G.) wrote:

I dont quite understand why one would need to change the circuits around
if the machine was working with the circuits it has now and buying books
on black boxes will remove the short from his power supply .

For the untrained it may be hard to explain how and where to start
testing parts to find the short .

Before you buy books on black and gray boxes take the boxes out and take
the covers off of them . The most common problems with those was bad
solder connections on the tall rows of pins . Resolder all of them with
fresh solder .
If someone got careless with the ``record playing`` lightbulbs and put
in the wrong bulbs or shorted across their sockets it can short
transistor-s in the black box again another hard to explain to the
untrained at this .

Good havens the guy is going to spend more on books than the machine is
worth

The circuits were redesigned because the -13 and -27 VDC power
supplies need to track. As originally designed, one could increase
while the other decreased due to component aging. With the revised
design, the -13 was developed from the -27, so whatever the -27 did,
the -13 followed.

If you want to destroy the customs, go ahead and resolder. They were
correctly wave soldered at the factory, and it is doubtful any of the
chips need to be resoldered. What would cause them to become
unsoldered? Flexing the PC board can crack traces. An uncareful
disassembly of the black box can easily casue this.

You are correct, howver in that replacing a bulb with an incorrect one
can easily destroy the driving transistor inside the black box. Be
careful to only replace bulbs with the correct ones, as documented in
the manual.

Cheers,

Tony Miller

No please do not solder any of the ic chips !
Read my post carfully and notice i said TALL ROWS of pins . These are
the pins that connect the boards together inside .
I bought a STD4 machine and was given 9 sets of these black & gray boxes
with it all marked ``bad`` , sure enough none of them worked right ..
kept making the reset ligh come on .
I fixed all of those boxes , 7 of them by soldering the tall pin
connectors and the other 2 had shorted bulb driver transistors in them
that i replaced .

I have nothing against books and manuals on things . I find it strange
that most will share exactly how to fix almost any problem with a
jukebox here but when the black boxes are mentioned all i see is ``buy
this book`` . Buy the book , read it all and enjoy then sit down and
solder the pins .

I just got done going through several mid 80`s jukeboxes . They all had
their manuals inside . I read the manuals troubleshooting sections and
it only gave simple solutions but beyond that it said ``replace the XX
board`` ya RIGHT .. i resoldered those tall pins around the boards
where all the wire connectors plugged into the board and that cured 90%
of the problems the rest was weak capacitors ( ESR meters are great )
No where in those manuals mentioned any possible bad solder joints .

On Sun, 12 Aug 2007 09:16:46 -0600, (Ken G.) wrote:

No please do not solder any of the ic chips !
Read my post carfully and notice i said TALL ROWS of pins . These are
the pins that connect the boards together inside .
I bought a STD4 machine and was given 9 sets of these black & gray boxes
with it all marked ``bad`` , sure enough none of them worked right ..
kept making the reset ligh come on .
I fixed all of those boxes , 7 of them by soldering the tall pin
connectors and the other 2 had shorted bulb driver transistors in them
that i replaced .



I have nothing against books and manuals on things . I find it strange
that most will share exactly how to fix almost any problem with a
jukebox here but when the black boxes are mentioned all i see is ``buy
this book`` . Buy the book , read it all and enjoy then sit down and
solder the pins .

All the book attempts to do is to teach how the system works, and to
present a logical troubleshooting procedure to fix one that doesn't.
It does indeed talk about intermittent solder connections.

I am very happy that you managed to fix several boxes just by
soldering the interconnect pin connections, and a couple by replacing
blown out transistors. What will you do when you come across a box in
which that repair technique doesn't work?

Cheers,

Tony Miller

I just got done going through several mid 80`s jukeboxes . They all had
their manuals inside . I read the manuals troubleshooting sections and
it only gave simple solutions but beyond that it said ``replace the XX
board`` ya RIGHT .. i resoldered those tall pins around the boards
where all the wire connectors plugged into the board and that cured 90%
of the problems the rest was weak capacitors ( ESR meters are great )
No where in those manuals mentioned any possible bad solder joints .

What will you do when you come across a box in which that repair
technique doesn't work?
Cheers,
Tony Miller

Hi Tony .. about the only other thing that could go wrong is a
resistor-s or diode-s after that possibly an IC chip .
I had a conversation with a guy who serviced those using the special
test equipment made for them . He said it was not common to find a bad
IC chip in those so that lowers that chance .

As for your above question .. i would use one of the repaired boxes i
saved from that stash i have . If a had no stash i would go looking for
another box off ebay or somewhere .

Other notes as i was told those IC chips can be destroyed by static
charges so you dont want to be up & down and scuffing across carpet
during any of it . Sit and stay there till your done or discharge
yourself after you sit down .
I would not mind servicing those if i had the equiment as i sold off the
jukebox i had .