Line voltage on both sides of play control switch

[e093116]

Hello,

I'm working on the 3rd of 4 jukes that I bought as winter projects from a 95 year old ex-operator...this one is an STD160 and my first foray into a black & gray box machine.

Things were going well until the motor stopped working in the middle of a scan.  In troubleshooting, I've noted the motor resistance is 105 ohm (red to blue) and 255 ohm (green to yellow) and the start capacitor measures 2.1 uF and 0.95 uF.  I've also noted that I have good voltage (117-120 VAC) at the reversing switch.  On the surface, I think these things are ok.

One thing that I have noticed, in reviewing the mechanism motor power service diagram in the manual, is that I have line voltage on both sides of the play control switch, with the switch open.  I believe this is a simplified diagram and that I should only have voltage on one side of the switch with the switch open (I am measuring between the switch solder contacts and the connection of the power cord to the terminal strip near the transformer and have the mech plug disconnected from the DCC).  Can anyone confirm this or provide any other suggestions?

Thanks for the help.

Bill   

[Ron Rich]

Hi Bill,
Seeburgs last used a "start" cap, in 1948 ! Newer Seeburgs depend on a dual value, motor run cap. On the STD series models these run caps should measure 1.65, and .75 If you have "120 VAC" at the white/yellow wires on the reversing switch, you have either a "Jammed" mechanism, or a bad motor, or cap (can you turn the MOTOR COUPLING, by hand??).
I don't understand exactly what you are "measuring" in the DCC, However if you are using a "digital" type meter, it is probably reading voltage, but no current, due to the .01/14k cap that is hopefully, still soldered across the switch. Ron Rich

[e093116]

Hi Ron,

Yes I'm using a digital meter (Fluke 87).  The cap is still there across the play switch.  Your comment about what I am reading on the meter makes sense.  Thank you.

The 2.1 and 0.95 values are what I measured for the run cap, which is a bit higher than the specified values of 1.65 and 0.75.  I have isolated(disconnected) the run cap from the wiring for the measurements.  Are these values too high? 

I have removed the motor coupling.  The motor spins freely by hand.  There is about 1/8" of end play.  The motor resistance I measured seems reasonable, based on a previous post by Rob in another thread, I did put paper between the reversing switch contacts to isolate the motor wiring.  I had previously disassembled and serviced the motor as described in your book (and similar to the slow LS1 motor I asked about last week, which is fine) before turning the machine on, and it ran good for an hour or so of actual run time before the problem occurred. 

With the motor coupling removed, power applied (play control switch closed), and run capacitor in the circuits, I can feel the motor hum/shake slightly like it is getting power, it will turn slowly in one direction, sometimes I need to "help" it to start moving, if I actuate the reversing switch by hand to reverse the motor, it will slowly come to a stop but will not rotate in the other direction, even if I try to help it.  I can see both sets of reversing switch contacts arc lightly when the switch changes state, so I think power to the motor is getting switched correctly.

Any thoughts or comments on additional checks on the motor before declaring it bad/trying out a replacement?

Thank you.

Bill

[Ron Rich]

Bill,
Which brand motor is installed in that phono ? Sounds as if it has been run "out of oil" !

[e093116]

I installed a new cap this weekend, with no change.

Changed out the motor and the "problem" went away.  I'm still a bit stumped as to why the motor worked and suddenly quit. The one thing I did notice is that some of the windings appear blue/green colored in two places, I suppose the wire could be compromised due to heat and/or corrosion, but the varnish on the wire appears to still be good.  On other coil/wound items, I've generally seen a black/burned area where it got hot and also been able to measure a different resistance from what is specified. 

[Ron Rich]

Hi Bill,
If it was a NIDEC brand motor, I'm not surprised--these motors, typically, if run without oil, heat up drastically, and eventually either freeze up, and or, have open windings-- Bodine Brand motors are much less likely to be damaged. Usually, if they "run outta" oil,they can be opened, cleaned and re-lubed, properly, and they will be on their "merry way" ---- Ron Rich