Seeburg AY160 - Scans twice error, but with a twist

[hourglass]

I've searched the web up and down, but I haven't found any posts related to my specific problem.

I've corrected quite a few issues with this Jukebox, which I got for free on Sunday.

At first, it would just scan twice and quit, like billions of other posts on the Internet describe.

I went thru the troubleshooter and replaced the 12AX7 near where the memory unit RCA plug goes.  

Now, when I make a selection, it trips instantly.

This leads to two scenarios:

1.  No record is playing. 

Making a selection (any number and any letter) causes it to load the record in the nearest slot and start playing it.  If the record finishes by itself, the unit scans twice and then stops right by the same record.

2. Record is playing.

Making a selection causes the unit to trip, ejects record, scans twice, then stops by the same record.  Making another selection goes back to #1.  I'm getting tired of hearing Magic Carpet Ride.

I appreciate any advice anyone may have!  

Going further thru the troubleshooter, I suspect a bad Timing Relay #2 on my TSU-3, but even with that if I manually trip it, shouldn't it not instantly trip again when a record is playing when a selection is made?

Ryan

[hourglass]

Got it working.

Turns out someone had tried to re-wire the RCA connector on the memory wire that plugs into the Pulse Amp. They didn't connect the 2nd wire to the shield. I clipped it temporarily with an alligator clip and now it's selecting all day long. I'll leave this post here in case it helps someone else out someday.

Ryan

[Spinner]

Hi,

I appreciate you posting this.  I have the same type of issue with my AQ100.   When a selection is made it trips before scan begins Write in working as selection is held as when tripped record finishes it scans to selection I made.    Each selection trip record on or off turntable.  Unfortunately replacing the RCA plug did not work.   I believe there is a short to ground in the write in circuit but I cannot figure out how to test or debug.  The schematics has timer relays in it but I do not have them on my unit.  I think the stepper and timer relays come with the remote selector package that I do not have.  Do you have any thoughts or ideas on how to test.   I have the manuals but the tests do not seem to be conclusive or leading me to root cause.   I am going bonkers trying to figure out.  I pulled the section mechanism and cleaned.  I even had all unites out of juke box trying to test by running a alligator clip ground to all components.     Any thoughts on how to debug would be appreciated. 

[robnyc]

"Spinner" -this sort of thing is caused by the following:

Inadequate ground return connection on the Jones plug from the tormat. It is pin 33 as seen on this 200 tormat diagram: www.flickr.com/photos/90641375@N06/36140664003/ These old plugs often develop resistance on their pins and I find to be the most frequent cause of errant tripping.

A 12AX7 that has developed hot spots on it's cathode. In rare cases this can also happen to the thyratron tube (2050)

A very leaky 0.047 capacitor in the pulse amp

Make sure you have connected the wires from the tormat RCA plug correctly: Red and shield to shell. Green to center pin.

Since you have a feed-through plate in place of the stepper, check continuity of the ground returns.

The pulse amp has several coils and capacitors inside that filter and shape the pulse coming from the tormat. I've only found one case of defects here which was an open coil connection, if you have another pulse amp try it.

RobNYC

The timing relays in the stepper have caused this problem, but don't apply here.

[Ron Rich]

Rob,Spinner,
FYI--All TMU's were not wired with the same color pulse output wires, nor were the colors always soldered in the same orientation. If in doubt, easy check--dis-connect wires from plug, ring end and measure them --shield and brade should show connection in all TMU's except, some TMU-7's.
Ron Rich

[Ron Rich]

Spinner,
If your Service Manual does not show the TJU-2 connections, you have the wrong service manual for your phonograph.
Ron Rich

[Ron Rich]

Just occurred to me-- ( I am having medical problems at this time), you can also be having ES problems causing this. To cure it, I found the ES MUST be removed from the phono, solenoid and meter(s) removed. the the ES must be washed in hot soapy water--then rinsed and re-washed in (sudsy, if you can get it, ammonia--dry totally prior to use--re-lube as per manual--use NO spray of any kind !! Ron Rich

[Spinner]

I appreciate input. This weekend. I have cleaned contacts of jones plug. No change. I have cleaned selection mechanism. No change. I replaced 12AX7 tube, No change, Unit recapped 3 years ago, I have place order for new 2050 tube. I am hoping but not optimistic this will fix issue.

With my Vogue II I had issues with contacts of cartridge. I had to take apart and close up contacts of 4 prong female plug that carriage plugs into. It was a challenge to do as I plug was easy to take appart but difficult to put back together. I found I had to desolder contacts, assemble plug and the resolder contacts. I am starting to think I need to do with Jones Plug and fix 33 contact as suggested. However I am concerned that it will be more difficult than cartridge. Any thoughts on this would would be appreciated?

[Ron Rich]

Spinner,
I assume that you have "cleaned the selection mechanism" ( also assuming that the "selection mechanism" is the TES) correctly--and totally dried it prior to re-use ? Have you checked the resistors/cap in the PA unit ? Is your negative DC voltage OK ? Have you cleaned the k contact INSULATOR, in the pricing unit ? Ron Rich