Seeburg 160 - One Number Not Selecting

[bidnadir]

Hi Ron,

Okay, I plugged both Jones cables back in, and then from the back of the door (panel removed) I checked for continuity between PIN 22 on the back of the TMU plug, to the corresponding #2 wire that leads into the Tormat Mememory Unit. All of this can be a bit confusing in words, so I have taken a couple of photos specific to this test and put them in a different album, you can view here. Continuity tests good in this test.

photos.google.com/share/AF1QipOYWDRtVMwr-QvYkigKRNk4KE5FauofnEDxUSpIJ6oPeP7Vtec3olAdwiz9NTNeoQ?key=X3RvMnpmTXU4TEdSR2o1QmhUOEd6Tkt0VWQwSnNR

[robnyc]

Charles, you are going in a different direction here.

What I suggested is to test from pin 22-31 on the --male Jones plug from the tormat-. That is the unit under the record rack. Remove the plug from the selection receiver. Check also the other pins from 21-30 again to pin 31 just for reference.

I note that the strain reliefs (cable clamps) are missing from both Jones plugs so there is a good chance that the break has occurred in the plug due to repeated flexing.

RobNYC

[bidnadir]

Hi Rob,

I think is the correct spot / Jones Plug. There is no continuity between PIN 22 and 31 in this photo. Please take a look at the photos at this link to ensure I am checking the right plug. Appreciate this.

photos.google.com/share/AF1QipMQsHLm6WT2xun8YyF1GtkmOCeJv7oZe5MKYpGupWYwPHlzdGLS7AIcpfca7JwsFA?key=b1NfWE5STU5hMWdLdnpqUW1DRkcwLWdwRE03d0dn

CW

[Ron Rich]

Rob, Charles,
I just checked a TMU I had laying around ( which someone marked "BAD"--but I think I tested it years ago as good? ), and there is NO continuity between 31 and anything ! I looked at the "full schematic" Seeburg put in the Service manual, and find it, unlike most Seeburg Schematics, somewhat confusing-- as it "sorta" shows 22-31 connected--but using a square block rather then the traditional "dot" connection.
Ron Rich

[bidnadir]

Hi Ron, I have tried emailing you at the email you'd provided [e-mail] but it's bouncing back. Can you please send me the instructions on how to open the TMU and test procedure.

Really appreciate this. Thanks Ron.

Charles

[Ron Rich]

Charles,
My email is: [e-mail]

[robnyc]

Sept 2, 2017 13:22:53 GMT Ron Rich said:

Rob, Charles,
I just checked a TMU I had laying around ( which someone marked "BAD"--but I think I tested it years ago as good? ), and there is NO continuity between 31 and anything ! I looked at the "full schematic" Seeburg put in the Service manual, and find it, unlike most Seeburg Schematics, somewhat confusing-- as it "sorta" shows 22-31 connected--but using a square block rather then the traditional "dot" connection.
Ron Rich

Ron, you have a bad tormat. I dug out a 200TM2 and find continuity at near zero ohms from pin-21-30 through to pin 31.   The simplified I posted is vague as well about the connections of all number leads to pin 31. Though there is a tiny dot I should have added a larger one to avoid confusion when showing that to other people.

I have seen several bent tormats. the obvious ones were thrown out during the cleanout of MJL operating on Tenth ave.  Of those I kept, one 160 was used in making up a showcase-LS-LPC hideaway in early 1992.  I didn't notice that the tormat was bent up slightly at the left end end till I finished the mashup and saw the readout-tormat distance change about 1/8 inch at that end. It still worked so I used it.    A 201 I bought in early 1994 for use had 4 broken readout loops and on groups loops. Oddly, it didn't show any deformation. I used #24 wires to repair several and just a dot of solder to bridge the gap on one. It is still in service.

Rob

Rob

[Ron Rich]

Hi Rob, Rob,
OK--I'll pull this one apart tomorrow, if the heat wave subsides ( been over 100 here the last three daze !) to see whut I can find--

[bidnadir]

Hi Ron,

I have popped you another email. Greatly appreciate your help with this.

Ron & Rob: Given I have continuity all the way from the #2 keyboard switch to the corresponding wire that enters the Tormat Memory Unit, I think the issue must be in there, so will await your email instructions before I open 'er up.

Also, just an FYI, the lack of clamps on the Jones plugs and the lack of insulation on the cables is due to me testing. I had the Jones apart so I could test both sides as was hoping the fault was there. Unfortunately not, so now to open up the memory unit.

Really appreciate all the help and info !

[bidnadir]

Hi Guys,

Well if I was frustrated before, I am doubly so now. I successfully (and carefully) opened up the memory unit and have tested the black wire (which corresponds to the #22 plug & #2 keyboard key), and have good continuity where it connects inside the memory unit. Please view this photo: goo.gl/photos/zTGrJgQacSq7QymL9

Other test results:

- From the same point inside the memory unit there is good continuity all the way back to keyboard #2 key wire.

- With the opened memory unit plugged back in, there is no continuity between the #22 PIN and the #31 PIN, but good continuity between #31 and the other PINs: goo.gl/photos/rASC7xqaEJHkpd8x6

- With the memory unit open and plugged in, good continuity between PIN #22 to the opened memory unit black wire that corresponds to #22 and keyboard key #2: goo.gl/photos/QvhKqrMuYBgHj6v98

Any ideas on what to test next ? Thanks again for all the help.

Charles

[robnyc]

Charles, it is a straight-forward case of visually tracing the tiny wire that comes from the terminal where the wire from pin 22 joins to it.

In the few times i have dealt with this it was always at points where the wire turns a corner or where it was soldered. Group 2 is right near where the cable enters.

When you begin to trace the wire itself a --careful-- probing with a tiny pointed object is used to slightly wiggle the wire and this will cause the break to show up. I used the probe tip from a meter, but a pencil or pin will do. have good light and some magnification.

When you find the break first determine if it can be patched by simply scraping off the insulation, i use a tiny flat blade screwdriver, and butt soldering the two ends. This works OK when the break occurs at a rigid point where the solder will also stick to the plastic and hold the joint, but not along a free run. There you'll have to thread a new wire -either all the way or just from one side of the break.

Any insulated wire that is small enough can be used.

While open, test all continuity and especially from each rivet to the center grounding plate under the tormat.

Rob

[Ron Rich]

Hi Charles,
I can't read your meter well from here, but it appears that either the meter battery is low, the ohms adjustment is not "zeroed", or you have a poor connection--probably a cold solder joint, in that circuit -- I would find "31" inside the TMU and check at that point for a broken 22 wire--The wire can be broken, as Rob says--anywhere, or poorly soldered anywhere--your meter, if working well should show almost no "resistance" anywhere.
Ron Rich

[Ron Rich]

Charles, Rob,
I may have discovered something here--on the schematic Seeburg issued of the TMU, they show terminal 31 and the others joined with a square "block", rather then the customary "dot". after some careful observations, I noted that the TMU I have here was open between all of these points. As I think I noted earlier, it's been awfully hot here--over 100 in the shop--so I've kinda not been working--but I looked at that TMU again yesterday, and noted that most of the screws that hold the grounding bar were missing and that those still left were loose. I replaced the missing screws--tightened the others, and re-checked continuity--guess whut ?Yep it's now good! So, MY conclusion is that the "block connectors" shown on the print are indicating that this is joined by that grounding bar ? You might check your screws are tight--do not"over-tighten" them, as they are held only by "Tinnerman" nuts ! Ron Rich

[bidnadir]

HI Ron and Rob,

Just wanted to provide you both with an update on this. I very thoroughly and carefully inspected the TMU with a magnifying glass and lots of light numerous times over a number of days, and did find one wire that was broken, but it was not the issue. I suspect this one wire may have been broken when I opened the unit as it was for a specific letter in a different number group. In any case, it wasn't the issue. The reason for my delay responding here is that I spent many hours over many days hunting for the issue, by gently touching each wire as was suggested, and visually inspecting every wire and route. I really did not want to give up on this one, but have come to the conclusion that the issue must be within the #2 Toroid itself which is impossible to get to (as far as I can tell) without completely destroying the unit.

Also, with the base plate at the bottom of the TMU removed, I did tighten all of the screws underneath, and also tightened all of the screws on the top of the TMU holding each number group board. When that did not have any effect, I loosened and re-tightened all of the screws, thinking that may assist with the connection, but again, to no effect.

Given I believe the issue is deep within the inaccessible toroid area of the #2 bank, that leaves me in the situation of needing to source a new TMU. The one I need is part number 160TM1. I don't suppose either of you have one or know a source to enquire with ?

Thanks again for the help.

Charles

[Ron Rich]

Charles, Sorry about that--check with the sources listed above, in the FAQ's--- Ron Rich