Tech help: Seeburg AY100U - Always energized trip coil
Corvette Bob
Just picked up my first jukebox and trying to get it operating
correctly. Here is the symptom - When first turned on and no
selections made and still in scan mode; the trip coil becomes
energized after 2 to 3 seconds. When I do make a selection, it will
stop wherever it wants and try to load a record. It loads the record,
clamps it, and just when the needle starts to make contact with the
record, rejects it. It drops down without issue - then starts the
cycle and repeats it till powered off. I checked the safety plunger
and that works fine. I also checked the record trip switch and that
works fine. I even removed the ground connection for the record trip
switch without any difference. I took the trip coil out, inspected &
cleaned it and installed a 1 amp fuse in the circuit. I found that the
trip coil is constantly energized. The 2050 tube looks good but I will
test it on a friends tester this week. Been reading some tests for the
tube and will try them as well later this week. I've noticed that the
cam switch has some contacts not correctly set. Could this cause my
problem? I've used carbon tetrachloride to clean electrical contacts
in the past. Is this OK to use on these contacts? Might be a little
overkill, but I don't think it would hurt them. One last note - If I
hold down the release lever, it will play the record completely but I
can feel the vibration from it being energized. Thanks for any help
you can provide.
Bob
Tony
The key words are that this happens *after 2 to 3 seconds*. I'd guess
the selection receiver has problems and may need a complete rebuild if
it hasn't been done yet. If the solenoid pulled in immediately I'd
steer toward the mech first, and actually that is still a possibility.
You will need to obtain a set of operation and troubleshooting guides.
Probably cost $40 to $60 but is a very wise investment. If you prefer
to send the selection receiver out for rebuilding, lots of people,
including me do that type of work.
Tony
Corvette Bob
First - thanks for your reply and offer to work on the amp and
receiver. Always nice to have someone available who can do this kind
of work. I was told at the time I bought this machine that the amp
and receiver were already rebuilt, but I can see some of the old paper
caps still present and a few, new mylar caps added. I have a couple
of good manuals that I've been reading and trying to understand the
mech, receiver, and amp system. From a previous Tony Dziedzic post
about a similar problem: "Pulling the 2050 tube immediately after the
mechanism trips, but before the record has fully transferred into play
position, prevents the trip solenoid from being energized by the trip
switch." I'm hoping to do this tube trick later this week when I can
get a friend to help me. Assuming it is a receiver problem - is there
a test to do to narrow down the possibilities where the problem is?
I'll report back and hopefully this info will help others if they ever
experience a similar problem.
Bob
Tony
> Hi Tony,
> First - thanks for your reply and offer to work on the amp and
> receiver. Always nice to have someone available who can do this kind
> of work. I was told at the time I bought this machine that the amp
> and receiver were already rebuilt, but I can see some of the old paper
> caps still present and a few, new mylar caps added.
OK, it wasn't rebuilt. It was half ass patched up.
I have a couple
> of good manuals that I've been reading and trying to understand the
> mech, receiver, and amp system. From a previous Tony Dziedzic post
> about a similar problem: "Pulling the 2050 tube immediately after the
> mechanism trips, but before the record has fully transferred into play
> position, prevents the trip solenoid from being energized by the trip
> switch." I'm hoping to do this tube trick later this week when I can
> get a friend to help me. Assuming it is a receiver problem - is there
> a test to do to narrow down the possibilities where the problem is?
The first step in narrowing down the problem is to rebuild the selection
receiver, then see if has any problems.
Tony
Corvette Bob
> The first step in narrowing down the problem is to rebuild the selection
> receiver, then see if has any problems.
>
> Tony
Hi Tony,
I've noticed a few "rebuild kits" for amps and receivers being sold.
Has anyone tried these and if so, do you have any recommendations.
Same goes for the amp rebuild kits. It seems that they mostly replace
some or all of the caps. Do you then check the resistors for proper
value? I've been having trouble with my internet provider and haven't
been able to post for awhile. It always seem to be a problem just
when I need it the most. My original plan was to get the machine
working, then pull it and rebuld the amp, receiver, and do the
cosmetic work on the cabinet. Now, I'm starting to think that your
suggestion is probably the correct way to proceed. That being,
rebuild the receiver first and see if that solves the ground problem.
Any comments re: this strategy? Also, I'm missing a few of the
amphenol black connector covers. Does newark or graybar or similar
companies sell just the covers? Thanks for any help you can provide.
Bob
Tony
On my other reply I forgot to state what many of us believe.
Do not plug in the juke box until the amplifier and selection receiver
are rebuilt!!!!! You run a high risk of burning up a transformer or
two. This is the golden rule!
I don't buy rebuild kits so I can't rate them except if they don't
replace every cap, it's not a complete cap kit. Re: Resistors, I
normally check/replace them as I'm replacing the caps. The connector
covers? Try John Durfee or see if someone here contacts you.
By the way, is the mech under the cover unusually clean? On older boxes
you could get away with allowing the trip coil to get wet because it was
a much lower voltage (still not a good idea but shit happens), with
your machine the voltage is much higher and if the trip coil got wet, it
is probably shot by now. But you still need the rebuild first.
Tony
Corvette Bob
I did remove the trip coil to clean and check it out. It sure
isn't like the coils in most of my pinball games. A brass tube wasn't
what I had expected to see. But, it looked good and seems strong. I
did install a one amp fast blow fuse in series with it as suggested to
protect it. So far, not blown. I do like your first statement to
rebuild first. Makes a lot of sense. I'll start putting together a
list of the caps, etc for the rebuild. Is there a method you follow
rebuilding these that you've learned over the years? I'm more used to
circuit boards and not working with what I call "flying" connections.
I'll take a lot of "as found" pictures to use with the rebuild and
hope that helps as well. Thanks again and I'll keep the group up to
date as I proceed.
Bob
Tony
> Hi Tony,
> I did remove the trip coil to clean and check it out. It sure
> isn't like the coils in most of my pinball games. A brass tube wasn't
> what I had expected to see. But, it looked good and seems strong. I
> did install a one amp fast blow fuse in series with it as suggested to
> protect it. So far, not blown.
Good idea, and yes if it hasn't blown the fuse you should be OK. The
steel plunger and the brass sleeve work great together, not as good as
nylon like in a pinball, but one hell of a lot better than a steel
plunger with an aluminum sleeve, they are about the worst combo.
I do like your first statement to
> rebuild first. Makes a lot of sense. I'll start putting together a
> list of the caps, etc for the rebuild. Is there a method you follow
> rebuilding these that you've learned over the years? I'm more used to
> circuit boards and not working with what I call "flying" connections.
> I'll take a lot of "as found" pictures to use with the rebuild and
> hope that helps as well. Thanks again and I'll keep the group up to
> date as I proceed.
> Bob
Pictures are a great idea, take lots of them! Besides that, when
replacing a cap, cut or remove one lead then solder on the one new lead.
It looks so simple to cut out both ends of the cap and solder the new
one in, but it's amazing how quickly that second connection can *hide*.
You will find quite a few connections were there may be 2 caps and 3
resistors and all need replacing. Go easy one at a time, again it's so
easy for those easy connections to hide. Oh, when testing a resistor,
be sure there is no cap or anything else paralleled with it to throw off
the real reading.
Corvette Bob
I just posted on another thread in this forum that relates to
another problem I'm having but now looks like it may be connected. I
found a ground fault on pin 5 of J504 of the selector. So, your first
comments about first rebuilding were right on the money. I also found
a bad 12AX7 tube if my borrowed tube tester is working correctly.
I'll test all the tubes tomorrow to confirm it's ability. I'm not
sure if a bad pulse amp tube will continuously fire the 2050 or if the
ground somewhere on the 25vac buss would cause it. Ordered the
rebuild kit for the selector and should get that soon. Then will do
the amp and work on the mech after pulling it from the case. Thanks
for all your help and I will take a lot of pictures to help me with
the reassembly.
Bob
Philip Nasadowski
<75d60664-a6bf-4b3a...@21g2000yqj.googlegroups.com>,
Corvette Bob <bfle...@yahoo.com> wrote:
> I'm not
> sure if a bad pulse amp tube will continuously fire the 2050
From the schematics I've seen, it really shouldn't.
What you might want to do, once the unit's rebuilt, is check the bias on
the 2050. There's a test point for that. IIRC, it should be a negative
number, and grounding the test point will cause the tube to fire.
Did you check the trip switch and mech wiring yet?
My guess is you just don't have the bias supply because it's not working
right, and the rebuild will solve this.
Corvette Bob
I just spoke with a gentleman down in Texas who used to sell tubes
and other equipment and he too, said that a bad 12AX7 won't fire the
2050 but a ground on the 25v buss might. Hopefully, I'll find the
ground and eliminate it during the rebuild and find the power
transformer undamaged. I was surprised to hear that I could replace
the Selenium rectifier, cr501, with a silicon diode bridge without any
problems. He also said I could do likewise for the sel. rectifier
cr655 on the mechanism. I thought I read somewhere that you couldn't
replace a selenium rectifier with a silicon type diode, but must have
misunderstood. Looking forward to the rebuild and will update this
thread as I progress. Thanks again for your help.
Bob
Philip Nasadowski
<d9a3b481-d02a-43ed...@21g2000yqj.googlegroups.com>,
Corvette Bob <bfle...@yahoo.com> wrote:
> Hi Phil,
> I just spoke with a gentleman down in Texas who used to sell tubes
> and other equipment and he too, said that a bad 12AX7 won't fire the
> 2050 but a ground on the 25v buss might.
I'll have to dig up my Q100/160 book next weekend at home and look.
> Hopefully, I'll find the
> ground and eliminate it during the rebuild and find the power
> transformer undamaged.
Oh yeah, that'd be bad :(
> I was surprised to hear that I could replace
> the Selenium rectifier, cr501, with a silicon diode bridge without any
> problems. He also said I could do likewise for the sel. rectifier
> cr655 on the mechanism.
Hmm, been years since I saw one of those vintage mechs - which rectifier
on the mech was this?
> I thought I read somewhere that you couldn't
> replace a selenium rectifier with a silicon type diode, but must have
> misunderstood.
You can, but the lower voltage drop can cause issues. Most notably, it
puts an AMI into warp drive. You add a series resistor in that case to
slow it down a bit.
Corvette Bob
The selenium rectifier on the mech is located just to the right of
the large cam switch. It looks like it has a series resistor, R655
[120 ohm] already in place. I'll be sure to check it before installing
the silicon diode.
Bob