Seeburg 160 - One Number Not Selecting

[bidnadir]

Hi All, I am newbie on the forum and hoping one of you may be able to assist with a frustrating problem I am having with an AY160 where one number (#2) will not select.   All other letter and number combinations work fine.  

I have tested and confirmed continuity between the #2 keyboard switch lead and the "Electrical Selector Plug" (J552) and the "Tormat Memory Unit Plug" (J551).   I have also tried to test the keyboard switch and don't see any obvious issues with it (although perhaps I am not testing correctly).   When testing continuity at the keyboard between the wires connected to each letter and number switch, there is continuity (although with resistance) between all of the letters and numbers, but no continuity when testing with the #2 keyboard connection. (When I depress #2, there is continuity, but without the key pressed, there is none).   Any help, ideas or assistance would be greatly appreciated.

[Ron Rich]

Hi Newbie,
Not quite sure how/what you are testing, nor exactly what the problem is--
Which model phono are we talking about (AY-160, is a series, in most cases, number, not the total model number)
If ALL selections with the number 2 in them fail-- what happens if you check the read-out section using a D cell ?
What type meter are you using to check continuity ?
Look at the TMU wiring, near the mechanism--is it compromised where it enters the mech shelf and twists up to the the 2nd clamp -- this area, if not still clamped correctly tends to get cut by the scan control operational switch--too often ! Ron Rich

[robnyc]

"bidnadir: Take a look at these simplified diagrams:

www.flickr.com/photos/90641375@N06/36140664003/in/dateposted-public/ Write-in.

www.flickr.com/photos/90641375@N06/36809447281/in/dateposted-public/ Read out.

As you can see, the numbers form a common loop extending from a dedicated pin on the Jones plug to a return at pin 31. The 2's enter at pin 22. You should see the same continuity reading from all the "number" pins -that is pins 21 through 30 on the J Ones plug.

If the 2's are open it means a wire has broken either in the plug, cable or tormat. Opening the tormat should only be done after first opening the Jones plug and also wiggling the cable while testing the continuity to look for breaks.

It is extremely unlikely that all of just the 2 group of read-out loops would open.

RobNYC

[bidnadir]

Hi Ron,

Thanks very much for he response and the help. The full model number is AY160UH. When I check using the 'D' cell to play all the records, the machine plays all of the records, including those in number group '2'. The problem with the machine is that when you use the keyboard to select a record, it will play all letter and number combinations, but not any that include the number 2. When using the 'D' cell though, all records play, including the number '2' group.

I am using an analog ohm meter to check continuity.

The wiring that you have mentioned might be the issue as it doesn't appear to be clamped properly or neatly sorted. I have tested continuity all the way to the output on the "Tormat Memory Unit Plug" (J551), but its possible there could be a break in the wire between there and the tormat memory unit. is there a good way to test for this?

Again, appreciate the help.

[bidnadir]

Hi Rob,

Thanks very much for the diagrams and the info. As you have described there is consistent continuity on all of the number PINS, except for #2.

Checking continuity between the keyboard at #2 switch and PIN 22 on both the "Electrical Selector Plug" (J552) and the "Tormat Memory Unit Plug" (J551) indicates good continuity, so the break isn't there. On the output side of PIN 22 on the "Tormat Memory Unit Plug" I have also found good continuity there where it exits the plug. Therefore, I believe the problem is somewhere in the cable leading to the Tormat memory device or within the memory device itself.

I have taken your advice and checked for continuity at the keyboard while wiggling the wires leading into the Tormat, but can't get it to register. Prefer to not open that memory unit up, so is there anything else I should check first ?

CW

[Ron Rich]

If it passed the D cell test, it;s for sure not a read-out problem-- if you have not done so, check the TMU plug, to be sure you have contact with the mating socket on the TJU. Remove the cap on the Cinch-Jones plug and inspect the solder joint. If good, note wire color used and remove some of the cloth covering near the point it enters the TMU--check there-- Ron Rich

[bidnadir]

Hi Ron, I've checked the TMU and TMJ plugs and removed both of their metal covers, and have confirmed direct continuity between the keyboard terminal for key #2 , and PIN 22 on both TMJ and TMU plugs. Confirmed continuity on both sides of these both plugs with the covers off.

I am wondering about whether or not the problem could be in the Tormat Memory unit or the cable that leads into it, given the 'D' cell test confirmed actuation of all the records. Given it passed this test, doesn't that then mean that the TMU and the connections to it via the TMJ plug must be okay ?

Charles

[robnyc]

"...given the 'D' cell test confirmed actuation of all the records. Given it passed this test, doesn't that then mean that the TMU and the connections to it via the TMJ plug must be okay..."

Charles, the battery test uses the readout sensing loop to flip all the toroids at once. Then, as the machine scans it reads out all the readout loops -one for each rivet and toroid.

It does not test the write-in matrix.

If you look at the Write-in diagram I posted you see that each toroid has two wires run through it. There is actually a third which is the sensing loop. Since those are "simplified" diagrams they don't include that loop as it has nothing to do with Write-in.

To reiterate, if you find no continuity between pin 22 and 31 on the male Jones from the tormat -that indicates that the problem is localized to the tormat or cable.

Try opening the Jones plug and look for a broken connection at pin 22. With any luck, that's where it will be. Otherwise the tormat will have to be opened and that is a somewhat delicate operation which we can go into later.

BTW: As the machine scans does the distance between the readout block and the underside of the tormat appear to change-? I ask because sometimes a-holes use the tormat as a handle when lifting the mechanism and this will bend the unit and break the tiny wires inside.

RobNYC

[Ron Rich]

Hi Rob,
Have you actually seen a bent TMU ? I have ever seen one that has not been opened, bend ! Saw one on a 200 model once, operating without a cover, that had been bent slightly in the center--

Charles,
You will need to follow the TMU cable to near the entry point into the TMU, strip away some of the cloth, use a pin to poke into the #2wire, test it for continuity between the plug and that point in the wire. BTW that cable should be dressed thru the "slit" in the hole in the mech shelf, the cover should be closed, the cable should be clamped to the mech shelf floor, then clamped, again, to the "stand-off" on the right -- This clamp should be "inverted" to dress that cable to the right, and behind, the standoff. Do NOT open the TMU till you know how ! Ron Rich

[bidnadir]

Hi Rob,

I want to ensure I am testing the correct area. Based on your most recent post I have tested between PIN 22 and PIN 31 in what I think is the correct spot / Jones Plug. There is no continuity between PIN 22 and 31 in this photo. A picture is worth a thousand words, so 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

Also, I took a look at the TMU and it is straight and true.

[Ron Rich]

Hi Charles,
If checking when the TES is plugged in, and the #2 button is depressed, you should, read it there. If there then-double check it, thru the other C/J plug-- I would, however remove the door skin, and check it on the other sides of the C/J plug---Ron Rich

[Ron Rich]

PS,
Your speaker wire dressing is awful too-- this should be twisted together, and dressed across the top of the amp and TSU--there were clips to retain the wires there when that phono was produced--use wire ties today, if clips are missing. Ron Rich

[bidnadir]

Ron & Rob,

I did as Ron suggested and pulled the insulation back from the cable as it enters the TMU memory unit and tested for continuity using a pin between the #22 PIN on the TMU Jones Plug and where the cable enters the TMU memory unit. Unfortunately I get good continuity. Therefore, I believe the issue is inside the TMU Memory Unit. I have posted a few more photos. What's the best way to open this unit up, and how do I then trace the wire and test it? Appreciate all the help.

[bidnadir]

Hi Ron,

Once I get the trouble found and repaired, I will definitely take your good advice and get all the wires sorted, secured and organized.

Also, I have the cover off of the back door and have verified all of the connections between the two Jones plugs, and checked for continuity between those connections and the #2 wire on the keyboard, and all tests good. I did this both on the plug side of the Jones plugs, and on terminals with the cover off of the back door.

Charles

[Ron Rich]

Hi Charles,
Prior to opening the TMU, check continuity all the way back to the #2 key on the TES, from the wire at the TMU entrance--
Email me at: [e-mail], for TMU opening instructions--if needed.