My Seeburg model B has developed a short!

Last time I used it, a few months ago it worked fine but the keyboard didn't work, I could toggle the pin bank and it would play though.

Last night I plugged it in and pow, big sparks and lights dimming.

Powered it up on the Variac and sure enough, it's a dead short, trips the breaker on the variac with as little as 10-15 volts, also the Jukebox hums loudly.

If I unplug the Octal plug to the Credit unit the short goes away and the box powers up normally, does this sound like the Latching Solenoid has bit the dust, or what else could short that hard through that plug?

Well it had a short. I removed the keyboard and poked around without finding anything, obviously the 24 volt latching solenoid couldn't cause this issue even if it was shorted, which it isn't.

Plugged it back together and now it's not shorted, maybe the wires were shored together inside the harness somewhere, I did loosen the clamp on the octal plug but I can't inspect the wiring without cutting off the cloth covering, wiggling it around while it was on yielded nothing.

Anyhow it's not shorting now but I don't really trust it either, also it would make selections but it wouldn't play them, just clicked as it passed the active Pins, or occasionally it would pick up, start playing and then reject abruptly.

It's been 24 years since I did the first restoration on this box, the Receiver chassis has never been recapped so I'm going to start with that and see where it goes.

Eric,
Just a guess--I'm thinking that your short was not associated with that plug--I am thinking that the short was somewhere in the motor power circuit. It could have been something fell into the reversing switch, or, if still there, the small cap connected to the motor wire terminals, shorted, and has now "blown out" ( I have seen these explode, with enough force to destroy the mech cover--eliminate it, if it's still connected--do not replace it !). Check the reversing switch contacts for signs of "welding' or "pitting", clean, and re-adjust as needed, as per the Service Manual Ron Rich

Thank you Ron, I will look into that possibility.
The motor mounts are bad allowing the motor to swing back and forth, possibly it chafed a wire. Would you know where to get new mounts?

I started recapping the Receiver chassis tonight, not a lot to it capacitor wise, but there is one burnt resistor (two watt?) coming off the 2050 socket that I can't read, also Fuse "C" is supposed to be a 2A Slo-Blo, it had an AGC 15A in that spot, it may have been there since before 1964 for all I know, it may explain why no fuses blew though.

One capacitor in the credit unit had never been soldered on one end, most of these caps seem to just be snubbers for all the relays and contacts though so it probably wouldn't make a huge difference, perhaps none since it's been wired for free play most of it's life.

I think I have a manual for this box, I 'll have to figure out where I out it though.

Eric

Hi Eric,
I have seen the motors short like that--which brand motor is installed in you phono ?
The resistor is a 47ohm 1 watt-- if off pin 2. If you are not adding a wallbox, just clip the resistor off and forget it--
WOW--a "noblo" 15 amp fuse--If that's the one in the CCU circuit--good luck, as you MAY have some burnt coils in the SA unit ! I suggest a MAX of 1.6 slo blo be used there--
I would also strongly suggest that you purchase an electronic free play unit to add to the phono, if not already there--this prevents latch bar solenoids from "smoking", when the phono is on "free play"--or on coin play--( I do sell them--PM me if you wish to purchase one)
Ron Rich

Hi Ron, I finished the receiver unit, including replacing the Selenium bridge with a Silicone one, I do have a Wallbox I want to use eventually so I wanted to do the whole thing.
I cleaned all the contacts with some De-Ox so they are clean again.

Back together, first thing is the Keyboard and Credit canceling solenoid start jackhammering, stuck in some sort of cycle, if I unplug the Octal plug on the credit unit it stops and the Juke functions normally if I manually make selections at the pin bank.
All the contacts in the credit unit look fine. Any ideas where I'd start to look for this issue?

I haven't removed the motor cover yet to check that capacitor, the motor is original, it a round one, I forget the brand. I have a spare I bought for my Q100, it's square but I understand they are supposed to interchange? Anyway I think the motor is OK at this point.