Help: Rockola Sybaris 474

On Tue, 29 Jul 2003 23:04:11 -0400, "bele2009"
wrote:

Hi Group,

I working on my first juke, Rockola 474, original, non-restored condition.
It has some minor issues I'll have to work on. However I'm having two weird
problems I have no clue about. It may be a pinbank problem, but I'm not
sure...

The Read-Out carriage sometimes passes over some pins and make one or more
turns before "finding" a pushed pin and stoping at this position. I
suspected bad contacts, so I completely dismanteled the read-out carriage
and cleaned all contacts very carefully. That did not take care of the
problem.

Then, I connected a continuity tester between the read-out contact and the
chassis ground. It beeped when the carriage passed over the pins but the
scanning does not always stop. I tried cleaning the faulty pins with some
emery cloth and contact cleaner but it did not solve the problem either.

The other problem is that sometimes, the scanning process stops too far and
the whole mechanism is out of sync. The gripper arm does not land properly
on the record and misses it completely. It seems the problem is worse on
some selections than others but it's hard to tell.

I also have the service manual, part list and schematic for my jukebox, if
it may help

Any idea please?

Eric


Eric:

I suspect that the two problems you have are two manifestations of the
same problem. I don't have a manual handy tonight, but as I recall,
when the carriage makes contact with a flipped pin, the circuit is
completed and braking current is applied to the magazine motor to stop
it.

There is a relay involved in this circuit that may not be energizing
due to bad coil, no current (something wrong in circuit) or a bad A/B
switch. Note that on one rotation, the carriage will only stop on the
A side pins, and the next rotation it stop only on the B side pins.
This is selected by the A/B switch (located near the magazine at the
front of the mech frame - hidden underneath with a linkage that moves
up and down based on a follower that runs in one of two groves in the
magazine gear).

If I recall properly, there is a good explanation with pictures in the
service manual that shows all the components involved in every step of
the operation. These pics also show hwere the components are located.

First suggestion is check the A/B switch to make sure that there is a
low resistance continuity on both A and B contacts - one contact
activated on one rotation, the other on the next rotation..

If OK, check the applicable relay(s) to make sure they are operating
properly and making complete circuits through the applicable contacts
with low resistance.

Hope this helps.
Irwin

Hi,

I would like to thank the people who have helped me so far. Hope you can
help once more with my Rockola 474.

First, I received my service manual from VG last wek, but unfortunately it
is for a Rock-ola 477 jukebox. I send it back for an exchange but I don't
have it yet. In the mean time, I still have the Part List and schematic for
the 474.

I checked the A-B MicroSwicth and the contacts seem to be ok. I have less
than 0.5 Ohms in both position. I inspected the D.C. Interlock relays and
the gripper reversing relays in the control box and their contacts looked
burned and very dirty. I completely dismanteled these relays and carefully
cleaned and polished all contacts to a very nice shine. All contacts now
have very low resistance when manually opererated.

Then, I re-installed the control box in the juke-box and ran a test of about
20 selections. On 2 or 3 occasions, the magazine motor stopped too far; the
gripper arm was positionned about midway between two records and missed the
desired selection. Sometimes, the magazine does not stop as far and the
gripper is still able to get the record, but then the solenoid lever on the
Read-out carriage is positionned too far to push back the pin and clear the
selection.

I'm not sure I fully understand how the interlock relays work, and how the
control box brakes the magazine motor, but I'm suspecting sometimes it fails
to do the job.

I also noticed that the whole Magazine-Read-out carriage assembly has a
mechanical backlash of about 1/2 the space betwen two records. It is comming
from the magazine motor gearbox, but I don't think this is a problem since
the magazine motor never has to change direction.

What can I do now ?

Eric

"HCV" wrote in message
...
On Tue, 29 Jul 2003 23:04:11 -0400, "bele2009"
wrote:

Hi Group,

I working on my first juke, Rockola 474, original, non-restored
condition.
It has some minor issues I'll have to work on. However I'm having two
weird
problems I have no clue about. It may be a pinbank problem, but I'm not
sure...

The Read-Out carriage sometimes passes over some pins and make one or
more
turns before "finding" a pushed pin and stoping at this position. I
suspected bad contacts, so I completely dismanteled the read-out carriage
and cleaned all contacts very carefully. That did not take care of the
problem.

Then, I connected a continuity tester between the read-out contact and
the
chassis ground. It beeped when the carriage passed over the pins but the
scanning does not always stop. I tried cleaning the faulty pins with some
emery cloth and contact cleaner but it did not solve the problem either.

The other problem is that sometimes, the scanning process stops too far
and
the whole mechanism is out of sync. The gripper arm does not land
properly
on the record and misses it completely. It seems the problem is worse on
some selections than others but it's hard to tell.

I also have the service manual, part list and schematic for my jukebox,
if
it may help

Any idea please?

Eric


Eric:

I suspect that the two problems you have are two manifestations of the
same problem. I don't have a manual handy tonight, but as I recall,
when the carriage makes contact with a flipped pin, the circuit is
completed and braking current is applied to the magazine motor to stop
it.

There is a relay involved in this circuit that may not be energizing
due to bad coil, no current (something wrong in circuit) or a bad A/B
switch. Note that on one rotation, the carriage will only stop on the
A side pins, and the next rotation it stop only on the B side pins.
This is selected by the A/B switch (located near the magazine at the
front of the mech frame - hidden underneath with a linkage that moves
up and down based on a follower that runs in one of two groves in the
magazine gear).

If I recall properly, there is a good explanation with pictures in the
service manual that shows all the components involved in every step of
the operation. These pics also show hwere the components are located.

First suggestion is check the A/B switch to make sure that there is a
low resistance continuity on both A and B contacts - one contact
activated on one rotation, the other on the next rotation..

If OK, check the applicable relay(s) to make sure they are operating
properly and making complete circuits through the applicable contacts
with low resistance.

Hope this helps.
Irwin

Eric:

I believe that the backlash you mention is more than desired, but I
don't know if Rockola actually had a spec for this.

One thing that may be required is to time the mechanism. This
involves adjusting the readout arm to line up with the pin at the
proper postion so the gripper will pick up the record properly. The
manual shows this procedure fairly well. There is an adjustment screw
near the hub of the readout arm that adjusts the arm (spring loaded)
against the hub. There should be a molded in mark on the plastic read
out carriage that is supposed to line up with the pin(s) when the
adjustment is correct.

Hope this helps.
Irwin


On Sun, 3 Aug 2003 10:25:57 -0400, "bele2009"
wrote:

Hi,

I would like to thank the people who have helped me so far. Hope you can
help once more with my Rockola 474.

First, I received my service manual from VG last wek, but unfortunately it
is for a Rock-ola 477 jukebox. I send it back for an exchange but I don't
have it yet. In the mean time, I still have the Part List and schematic for
the 474.

I checked the A-B MicroSwicth and the contacts seem to be ok. I have less
than 0.5 Ohms in both position. I inspected the D.C. Interlock relays and
the gripper reversing relays in the control box and their contacts looked
burned and very dirty. I completely dismanteled these relays and carefully
cleaned and polished all contacts to a very nice shine. All contacts now
have very low resistance when manually opererated.

Then, I re-installed the control box in the juke-box and ran a test of about
20 selections. On 2 or 3 occasions, the magazine motor stopped too far; the
gripper arm was positionned about midway between two records and missed the
desired selection. Sometimes, the magazine does not stop as far and the
gripper is still able to get the record, but then the solenoid lever on the
Read-out carriage is positionned too far to push back the pin and clear the
selection.

I'm not sure I fully understand how the interlock relays work, and how the
control box brakes the magazine motor, but I'm suspecting sometimes it fails
to do the job.

I also noticed that the whole Magazine-Read-out carriage assembly has a
mechanical backlash of about 1/2 the space betwen two records. It is comming
from the magazine motor gearbox, but I don't think this is a problem since
the magazine motor never has to change direction.

What can I do now ?

Eric

"HCV" wrote in message
.. .
On Tue, 29 Jul 2003 23:04:11 -0400, "bele2009"
wrote:

Hi Group,

I working on my first juke, Rockola 474, original, non-restored
condition.
It has some minor issues I'll have to work on. However I'm having two
weird
problems I have no clue about. It may be a pinbank problem, but I'm not
sure...

The Read-Out carriage sometimes passes over some pins and make one or
more
turns before "finding" a pushed pin and stoping at this position. I
suspected bad contacts, so I completely dismanteled the read-out carriage
and cleaned all contacts very carefully. That did not take care of the
problem.

Then, I connected a continuity tester between the read-out contact and
the
chassis ground. It beeped when the carriage passed over the pins but the
scanning does not always stop. I tried cleaning the faulty pins with some
emery cloth and contact cleaner but it did not solve the problem either.

The other problem is that sometimes, the scanning process stops too far
and
the whole mechanism is out of sync. The gripper arm does not land
properly
on the record and misses it completely. It seems the problem is worse on
some selections than others but it's hard to tell.

I also have the service manual, part list and schematic for my jukebox,
if
it may help

Any idea please?

Eric


Eric:

I suspect that the two problems you have are two manifestations of the
same problem. I don't have a manual handy tonight, but as I recall,
when the carriage makes contact with a flipped pin, the circuit is
completed and braking current is applied to the magazine motor to stop
it.

There is a relay involved in this circuit that may not be energizing
due to bad coil, no current (something wrong in circuit) or a bad A/B
switch. Note that on one rotation, the carriage will only stop on the
A side pins, and the next rotation it stop only on the B side pins.
This is selected by the A/B switch (located near the magazine at the
front of the mech frame - hidden underneath with a linkage that moves
up and down based on a follower that runs in one of two groves in the
magazine gear).

If I recall properly, there is a good explanation with pictures in the
service manual that shows all the components involved in every step of
the operation. These pics also show hwere the components are located.

First suggestion is check the A/B switch to make sure that there is a
low resistance continuity on both A and B contacts - one contact
activated on one rotation, the other on the next rotation..

If OK, check the applicable relay(s) to make sure they are operating
properly and making complete circuits through the applicable contacts
with low resistance.

Hope this helps.
Irwin

bele2009 wrote:


I also noticed that the whole Magazine-Read-out carriage assembly has a
mechanical backlash of about 1/2 the space betwen two records. It is comming
from the magazine motor gearbox, but I don't think this is a problem since
the magazine motor never has to change direction.



That is way too much backlash/play. The motor that drives it is held in
place with three bolts, and the holes in the motor base are elongated to
allow for adjustment. Realign the motor so you have as little backlash
as possible, without having the gears mesh too tightly. You should get
down to under 1/4 inch of play.

Also be sure the record magazine is full of records, or at least, the
records are spaced evenly. A half full carriage with backlash can
certainly cause that problem as the weight of the records in one
position causes it to travel too far, or the opposite when the weight of
the records are at the other end as it stops.

Also, on the search arm there is an adjustment to align it with the
carriage. If needed, make that adjustment after getting rid of the
extra play. It's just a bolt that advances or retards the search arm.
Just push the search arm ahead a little and let it go back. You should
see the end of the bolt that stops it to where it is adjusted.

--
Tony

Thanks folks!

I finally found the problem. In fact it was two problems:

1) The #2 Outer Cam Switch on the gripper arm was not closing properly, so
the braking action on the magazine motor was not there. I readjusted the
switch. Wow! I'm impressed how fast the magazine stops now! I think this
switch is also used to supply power to the gripper motor circuit, because
since I readjusted it, the gripped arm moves much faster and smoother.

However, my jukebox was still missing records now and then. I decided to
take a look at the backlash I had on the record magazine. I found that the
end cap / stopper of the magazine motor gearbox was missing. The motor
armature was then free to move back and forth inside the gearbox. The
missing cap was lying around on the bottom of the cabinet. I reinstalled it
and voila! No more backlash (ok, maybe 3/16 to 1/4" at most). I then
realligned the read-out arm as suggested.

The scanning now works and stops perfectly, everytimes. I still have to
clean the pinbank and a lot of things, but for now, I'm impressed how well
it works.

This group is great!

Eric

"Tony Miklos" wrote in message
...
bele2009 wrote:


I also noticed that the whole Magazine-Read-out carriage assembly has a
mechanical backlash of about 1/2 the space betwen two records. It is
comming
from the magazine motor gearbox, but I don't think this is a problem
since
the magazine motor never has to change direction.



That is way too much backlash/play. The motor that drives it is held in
place with three bolts, and the holes in the motor base are elongated to
allow for adjustment. Realign the motor so you have as little backlash
as possible, without having the gears mesh too tightly. You should get
down to under 1/4 inch of play.

Also be sure the record magazine is full of records, or at least, the
records are spaced evenly. A half full carriage with backlash can
certainly cause that problem as the weight of the records in one
position causes it to travel too far, or the opposite when the weight of
the records are at the other end as it stops.

Also, on the search arm there is an adjustment to align it with the
carriage. If needed, make that adjustment after getting rid of the
extra play. It's just a bolt that advances or retards the search arm.
Just push the search arm ahead a little and let it go back. You should
see the end of the bolt that stops it to where it is adjusted.

--
Tony

bele2009 wrote:

Thanks folks!

I finally found the problem. In fact it was two problems:

1) The #2 Outer Cam Switch on the gripper arm was not closing properly, so
the braking action on the magazine motor was not there. I readjusted the
switch. Wow! I'm impressed how fast the magazine stops now! I think this
switch is also used to supply power to the gripper motor circuit, because
since I readjusted it, the gripped arm moves much faster and smoother.

However, my jukebox was still missing records now and then. I decided to
take a look at the backlash I had on the record magazine. I found that the
end cap / stopper of the magazine motor gearbox was missing. The motor
armature was then free to move back and forth inside the gearbox.




LOL! Yes, that will give it some play! Glad you found the problems.

--
Tony




The
missing cap was lying around on the bottom of the cabinet. I reinstalled it
and voila! No more backlash (ok, maybe 3/16 to 1/4" at most). I then
realligned the read-out arm as suggested.

The scanning now works and stops perfectly, everytimes. I still have to
clean the pinbank and a lot of things, but for now, I'm impressed how well
it works.

This group is great!

Eric

On Thu, 7 Aug 2003 09:56:32 -0400, "bele2009"
wrote:

The scanning now works and stops perfectly, everytimes. I still have to
clean the pinbank and a lot of things, but for now, I'm impressed how well
it works.

For what it's worth: I've fixed lots of Rockola's of that era, and
I've never had to clean (or do anything else) to the pinbank itself.
On fifties AMi's and Rockola's the selection pins get gummed up and
need to be cleaned, but the later Rockola design is pretty much
maintenance-free.

Now the wipers and wiper contacts are a different story. Those cause
lots of trouble and need to be cleaned. That may be what you meant
anyway.

I just got a mental picture of you trying to disassemble and clean out
the pinbank assembly, and it sent a chill down my spine.

Don't worry, I wont be dismanteling the pinbank. I played my jukebox all
weekend and it was flawless. However, the contacts on the read-out arms
looks a bit worn and I already ordered some replacements from VG. I suppose
after more than 86000 plays on my machine counter, the contacts need a rest
!

Eric

"Russel Willoughby" wrote in message
...
On Thu, 7 Aug 2003 09:56:32 -0400, "bele2009"
wrote:

The scanning now works and stops perfectly, everytimes. I still have to
clean the pinbank and a lot of things, but for now, I'm impressed how
well
it works.

For what it's worth: I've fixed lots of Rockola's of that era, and
I've never had to clean (or do anything else) to the pinbank itself.
On fifties AMi's and Rockola's the selection pins get gummed up and
need to be cleaned, but the later Rockola design is pretty much
maintenance-free.

Now the wipers and wiper contacts are a different story. Those cause
lots of trouble and need to be cleaned. That may be what you meant
anyway.

I just got a mental picture of you trying to disassemble and clean out
the pinbank assembly, and it sent a chill down my spine.

True, I never tought of that , but you are probably right. I wish the had
put another digits to these counters...

Eric

"ThomasTeeter" wrote in message
om...
That machine counter isn't going to be accurate unless this jukebox
was used in a VERY SLOW location for only a couple years. This counter
has more than likely "rolled over" half a dozen times or better,
meaning your juke probably has well over half a million plays, and
probably closer to a million. I have CD jukeboxes currently on route
that have well over 500,000 plays on the meter (and your Rockola 474
is WAY OVER 20 years older than these jukeboxes...
The 474 is one of my favorite Rockola jukes outside some of the 50's
Rockolas. Nice looking box...

Thomas
E-mail: thomasteeter(at)budweiser.com



"bele2009" wrote in message
...
Don't worry, I wont be dismanteling the pinbank. I played my jukebox all
weekend and it was flawless. However, the contacts on the read-out arms
looks a bit worn and I already ordered some replacements from VG. I
suppose
after more than 86000 plays on my machine counter, the contacts need a
rest
!

"bele2009" wrote in message ...
True, I never tought of that , but you are probably right. I wish the had
put another digits to these counters...


I don't think Rockola ever came out with a six digit counter. At least
Rowe had enough sense to do this at least in models R84+ (perhaps even
earlier). The reason I even first brought this to your attention was a
model 474 that I was asked to shop out about 12 years ago. I happened
to have the video arcade games at this location and I gladly obliged.
Gave them an identical juke as a loaner while I worked on theirs. This
location had originally bought this jukebox new, and the pricing was
set at ELEVEN plays for a dollar. I suggested and asked them if they
wanted to me to reprice it at the going rate back then- about 1 play
per quarter/ or 7 plays for a dollar (maybe it was 5 plays for a
dollar)- and they acted as if I was COMPLETELY NUTS! In fact they
wanted me to give MORE music for the dollar if possible.... About 2
years later I finally convinced them to "try" one of my CD jukeboxes.
I promised that they would make more money than they were making with
their current jukebox giving them only 40% of the receipts from my CD
juke. My jukebox was priced at ONLY 4 plays for a dollar or 9 plays
for 2 dollars (cheaper than the recommended 3 plays for a dollar). If
I failed, I told them I'd give them the difference of their lost
revenues plus ten percent and take my jukebox back home with me after
three months. Needless to say I operated a CD juke there for the next
nine years until they decided to buy their own.
Got off track, but at any rate, it doesn't take much to flip that play
meter over when you are giving ELEVEN plays for a dollar....

Thomas
thomasteeter(at)budweiser.com