[Jukebox-list] Rockola 478 Reverse Relay. Chattering

[Gary Young]

John, although I am not familiar with your machine, I
very much appreciate it when members give updates like
this. Follow ups like this benefits everyone on the
list. It can be a bit frustrating sometimes when
members write in with a particular problem and you
keep wondering how the issue was resolved. You dont
always find out.

Thanks again

Gary
> 
> "John D. Taylor III" <johndt3 at verizon.net> wrote:
>   
> Update,
> 
> For those of you that were following this thread I
> thought that I would give
> you an update now that I have repaired the jukebox.
> First, I want to thank
> everyone that has replied with their
> suggestions,-thank you.
> 
> Failing to discover the problem after trying all the
> suggestions, I decided
> to order the manual. The manual was interesting and
> it provided several
> sequence of operations diagrams that simplified
> things. Nevertheless, it
> didn't tell me anything that I didn't already know.
> Frustrated, I decided
> to return to basics and start from the beginning. I
> had taken it for
> granted that I had to correct voltage because the
> LED light was on on the
> regulator. But, by this point I decided to trust
> nothing. I got my meter
> out with the intention of tracing the circuit
> voltage, point-to-point. When
> I read the incoming DC voltage it was 20 V instead
> of the 34 that it should
> have been,-I immediately switched to the AC scale,
> and there was 10 V AC
> combined with the DC voltage. It all made sense
> then, the chattering of the
> relay, the relay being able to hold itself in when I
> did it manually, and so
> forth. Of course, from there it was simple. I went
> in the power supply and
> changed the filtering capacitors, and the one on the
> front regulator board,
> even though this one was good. I put everything back
> together and it is
> working fine now.
> 
> It's funny how sometimes we get ahead of ourselves,
> forget the basics, and
> start making assumptions, (How Often I Forget the
> Phrase, Check Your
> Voltages.) I guess the strange part of this was
> everything did seem to be
> working right with the exception of the gripper arm
> not wanting to return
> the record to the magazine,-so I made the mistake of
> making assumptions
> about the voltage.
> 
> Anyway, thanks to everyone for their help. Even
> though it turned out to be
> a different problem than any of us thought of,- you
> did help me to affirm
> that I was checking the right things in the circuit.
> At least if anyone runs
> across this again we will have an added suggestion
> for the subscriber.
> 
> John
> 
> ---- a-Original Message-----
> From: jukebox-list-bounces at lists.netlojix.com
> [mailto:jukebox-list-bounces at lists.netlojix.com]On
> Behalf Of John D.
> Taylor III
> Sent: Sunday, December 02, 2007 6:57 PM
> To: jukebox-list at lists.netlojix.com
> Subject: [Jukebox-list] Rockola 478 Reverse Relay.
> Chattering
> 
> 
> 
> Greetings all,
> 
> I have recently ran across a 478 Rockola reverse
> relay that chatters when
> trying to pick the record up to return it to the
> magazine. During this
> chatter, the gripper motor jerks in time with the
> relay until the record is
> returned to the magazine. This is a very slow
> process. Unfortunately, I am
> not as familiar with the circuitry on this jukebox
> as I would like to be. I
> pulled the mechanism power Board checked the relay
> along with the
> components in the related circuitry. All appeared to
> be well, with the
> exception of two capacitors that were only a little
> out of tolerance,-which
> I replaced. I noticed that when the record is
> canceled using any of the
> cancel options if I activate reverse relay for a
> half a second with my
> finger, then, it will stay activated until the cycle
> is complete. During
> half sec that I am holding relay in by hand the
> transfer arm has not moved
> yet, so, none of the micro switches has changed
> position while I am holding
> it manually. The relay is self holding by the time
> the transfer shaft begins
> to turn within the cam switches on the end. I did
> found one forum where
> another mechanic had the same problem, he changed
> the mechanism control
> Board completely, but it didn't fix the problem for
> him, so I think I can
> eliminate the board.
> 
> 
> Okay, since I may have made this a bit confusing,
> I'll summarize. When a
> record is canceled the gripper motor begins a jerky
> movement to pick up the
> record and return it to the magazine, and a reverse
> relay is chattering in
> time with the jerk movements of the gripper motor.
> 
> I have the schematics, but not the manual. I really
> don't understand the
> sequence of operations on this jukebox. However, I
> do have a schematic, and
> I have tried to chase the circuit's all around this
> 9 foot square thing,
> this is when I realized I was in trouble and needed
> to ask for help. Can
> anybody help me with this problem? Can you tell me
> the sequence of
> operations for the circuit? Have you ran into this
> before and know the
> solution? I welcome any thoughts, and/or debates
> relating to this problem.
> 
> Thanks to whoever created this forum, it's been a
> great help to me in the
> past and I'm sure it will in the future.
> 
> John
> 
> 
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