Seeburg M100C

Sure looks like an original part to me. Are we taking about the same part? Like i said on the case of this is printed 5 Mfd 300 VDC. The DC part is throwing me off. All the motor caps i see are AC. Please stop using big words like stepper. . Remember this jukebox stuff is new to me.
Stan Ski

Hi Stan,
Yep--attza da one (small enough words for you ?) RTFM !!
Ron Rich

RTFM. I remember way back when i worked for Chrysler they would send us to there training center and one of the instructors would always say RTFB if you did not understand something. Only thing is i still do not understand is the DC and AC thing. Off the top of my head i do not ever remember replacing a cap that has a DC rating on it with one that has a AC rating on it. It just bugs me. Oh well whats a poor little Polock going to do? I did see that that site over in Germany does sell these caps and they do have a AC rating so i guess it is OK. Have to place an order at Mousers so i will get on from there
Stan Ski

Hi Stan,
I don't recall ever seeing it marked "DC" ( or anything else other then the terminal markings--3 and 4--, and if you would, RTFM, you would note it's directly connected to the transformer winding---
Ron Rich

Stan Ski wrote:Now i am confused again. Is this a motor type cap? If it is then is it used for start or run. Or is is just a good old standard mylar cap. I looked at Mousers and only found a few motor caps that were DC
Stan Ski

Stan, sorry about the confusion here. yes, this is a non-polarized cap (AC) because it has elements of both AC and DC across it.

Its purpose here is to strengthen and slightly lengthen the pulses coming through the 2050. In this circuit that tube conducts to produce positive pules of current at approx 150 vdc. It therefore not only acts as a relay-current amplifier, but rectifier too. In fact, it can be replaced with an SCr along with a triggering circuit. This is what I use to eliminate those tubes.

While you can of course replace that 5mfd cap with an oil-filled motor-run or even two electrolytic 10mfd caps negative to negative in series (this produces 5mfd non-polarized) I have long chosen the mylar caps because they are much more accurate in value and don't change over time.

They are also smaller and getting rid of that large cap allows convenient space for mounting a relay to control the amplifier tube heaters and a terminal strip with diodes, resistor and fuse to eliminate the 6X4 tube on the Tormat equipped machines.

I hope this explanation hasn't added to the confusion

Rob

OK, I have all the caps replaced. Ordered a motor cap even though i will not be using the stepper (no wall unit) but i was taught not to mess around and replace all the paper/wax caps. Maybe someday i will find a wall unit and at least i would know this cap has been replaced. Now i will go back and check the resistors. I also have to replace the line cord in the selection receiver. No big thing but i just find it a little odd that this one wire for it is brittle and falling apart. All the other wires are fine. At least it is not like some of the Zenith and Philco radios i have done. On those you can expect to replace or recover just about all the wiring. I would like to say thank you guys for the help. Hope i am not being a PITA
Stan Ski

Have what might another silly question but here goes. After i get both of these units done can i plug them plug the amp and receiver together and power them up slowly with my variac? Just thought this might be easier then installing these thing back in the cabinet. They are heavy. This way i would be able to see if the tubes light up and any other little problems like something getting hot or worse smoke!!!
Stan Ski

Stan,
A good question--not "silly" at all--
Answer--yes--no problem--unless something smokes !
Ron Rich

Thank you Ron, Just have a few resistor to replace in the amp and i will be powering it up. It has been awhile but i remember being in your town. My brother lived in Mill Valley and Sausalito for a long time and i would go visit him every couple of years. I love northern California. Not much use for the southern part. He is now living in Japan
Stan

Figured i would post this while it is still fresh in my brain. Using my isolation transformer and my variac i slowly powered this thing up. Everything seemed to be OK. No smoke or caps exploding. I could see the filaments burning on all the tubes except for one. The 5UG was dead. Checked it (good). Then started checking voltages. Plate voltage was nothing. So i started back tracking. Found out i did not have line voltage at the male or female side of 4 prong chassis plug. At least that made sense of not having plate voltage on the 5U4. Did some more back tracking and found two of the wires ran to relay # 1 of the selection receiver. When i closed the relay the it gave me my line voltage and plate voltage went up to around 750. I checked the resistance on that relay and got 41 ohms. Remember i have both chassis on the bench with nothing else connected to them other than power. I am thinking that maybe it has to be plugged into one off the other connectors to operate this solenoid. Help before i get myself in more trouble
Stan Ski

Hi Stan,
You ain't in no "trouble"--yet -- Yea, that's a normal situation. If you look at the schematic, you would note that the "service switch" is in series with the "play control relay coil". With out that switch closure, the is no motor, nor 5U4 voltage. (RTFM !! ) Ron Rich

OK, If i am reading you correctly you really can,t bench test these things as it was designed to have the other parts in the circuit. When i first seen no plate voltage i thought the power transformer was bad but then that did not make any sense since i had nothing to cause this. In any old radio i have worked on if i seen no plate voltage i would have to think the power TF was bad but i am learning there is more to these jukeboxes. YA, I know RTFM. Only problem with reading is it gives me a headache. Have to ask when they worked on these things in the shop did they have long test jumpers or work on there knees?

Stan,
I have a spare "service switch" I use--before acquiring this, a one inch piece of #12 wire, was what I used--
Ron Rich

Stan Ski wrote:OK, If i am reading you correctly you really can,t bench test these things as it was designed to have the other parts in the circuit. When i first seen no plate voltage i thought the power transformer was bad but then that did not make any sense since i had nothing to cause this. In any old radio i have worked on if i seen no plate voltage i would have to think the power TF was bad but i am learning there is more to these jukeboxes. YA, I know RTFM. Only problem with reading is it gives me a headache. Have to ask when they worked on these things in the shop did they have long test jumpers or work on there knees?

You can bench test the 100c mech, selector, receiver & amp. You just need the space to layout the components.
You'll need to connect the speaker (the field coil is part of the amp's power supply as you'll know from your work on vintage radios) and the test switches (as Ron pointed out). Both are easily removed from the cabinet.

Doing this, makes it a lot easier to work on!

Getting back to that pre amp. Is that someones home made part or what? The way it is wired in scares me. Wonder if someone has a diagram showing how it should be wired
Stan Ski