M100A and others grounded power cords ?

Ron and others,

I saw this old posting...
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Matteo,
Is this machine connected to 117 vac with a TWO wire power cord ? If so, "the hot side" of the power comes from the wall to the on/off switch on the rear door, then to the "play control relay", where those contacts should be open to stop it from going on to the reversing switch/ and the motor. The "neutral" is connected directly to the R switch/motor. Do you have a meter? If so, measure the resistance at the solder joints of the contacts of the relay with the POWER OFF ! It should be "open".
NOTE--if the power cord is THREE wire, and the third wire is connected to the chassis, remove the third wire, and check that the other two wires are correctly installed !! Ron RichRon Rich
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I have a new three wire heavy duty cord for my M100A. The inside of the box has the 1940's plastic rectangular surface mount double socket. My question is, should one remove the original double socket and find a surface mount grounded receptacle and then replace also the wire on the WSR3-L6 with a grounded plug?

I do not want to induce any ground loop hums or the like...

Thanks, James

Hi James,
I do not ever add a three wire cord to an original two wire system. A long time ago, I questioned UL about this, and their answer was also, not to do it. Doing so, "un-lists" the equipment. I install two new polarized cords, being sure the hot runs on the black side. One thing you should check on that model--there is a ground wire from the "cold side" of the latch bar solenoid, to the keyboard casting--it tends to be broken--replace it with stranded 18 ga wire. Ron Rich
P.S. I recommend all coin operated phono's be run on a GFIC.

Ron, technically -anything- one does to these circuits would un-list it, even adding fuses, but the machine will fail an electrical inspection if ALL outer metal points are not grounded.


Thankfully an inspector wouldn't know what he was seeing even if he could get inside these machines, but a real stickler will take a mater and test from ground pin to exposed metal.

Been there twenty+ years ago.

I ground them all and let the location liability insurance deal with anything that might come up. So far I've never had a problem (fingers crossed).

Rob

Thanks Guys on the cord issue. If you get a chance, take a look at the photos in the other thread I posted and comment. I will use a polarized 2 prong as this is for home use so I doubt anyone will ever look at it.

Best, James

An FYI to anyone working on a M100A.

When I went to put a new cord on the M100A, the Bakelite duplex box that is affixed to the inside of the jukebox had an issue.

The metal parts that make contact with the plugs are of a 2-part design. The spring contacts are riveted to the metal structure and in my case one of the 4 rivets was loose. The 2nd thing that I noted was that the metal cross plates should have been pinned to the Bakelite housing and were not. When you pushed in a plug, the metal could push back. If far enough it could hit the backing plate. If both sides did so you would get a direct short. If one side did the metal plate would be hot.

I found that our local hardware store still stocks the plastic modern version of the Bakelite flush mount duplex plug. Hey, it is even the same color brown! It is also polarized and has a ground. I am not using the ground.

I hope that the problem with the manufacture of my original duplex plug was a one off problem. However, if you are ever into a m100a or m100b, I would pull that plug completely out and check or replace it.

Best, James