Seeburg AY160U Scan Problem Help Needed!!

I can establish credit(s) [latch bar works], and when I complete making a selection(s), the selection buttons pop up, and the "Make Selection" light goes out, but the mech does not move (stays on the right). The Turntable does not move at all.

Using the service switch to add credits, the nickel solenoid does operate, and adds credits.

If I move the service switch to the left, the mech will scan to left, to the right and stop.

The selector counter does not change.

I am lost as to where I need to look next, the selector, the mech, TSU, USPU?

Bird,
In which position do you have the service switch, when you make a selection ?
If you move tat switch to the scan position then back to the operate position, how many times does it scan? Ron Rich

I have the switch in the middle position (RUN).

The mech is at rest at the right. If I move the service switch to the left
(spring loaded), the mech will move to the left, move to the right and stop.

If I hold the service switch to the left while the mech scans to the left, and then
reverses to scan to the right (and I let the service switch go to middle while the
mech is moving towards the right), the mech will go to the left again, and back to the right and stop.


I felt the counter, andit buzzed, but numbers did not change. I think part of the arms broke, but haven;t investigated too far. O cannot simulate a CLICK by hand on the solenoid, and the numbers didn;t move but the arns moved.

Following the trouble shooting, it brings me to:


14AY
IF COUNTER OPERATES, check 5U4 is lit. It is. SEE ITEMS 52-56 of mech (160ST5 Service Notes), and 1 of auto speed. ; I have no autospeed]

Mech Items

52. Open Motor Windings; not probable since motor runs both directions when service switch is pushed to left.
53.Turntable drive shafts binding. Not Binding.
54. "O" contact fails to properly close
55. Open capacitor (motor runs in both directions)
56. G,H,J,K contacts of reversions switch do not close. (will check in am)


I plan on putting a lamp across the counter wires to see if it lights. (Ron,
do you have any spares for a TES165 Counter?

Thanks
BB

"BigBird" -If you can get the machine to scan twice via the service sw. the scan control is probably Ok.

This focuses attention on the credit unit. It is possible the pitted blade contacts located on the underside of the credit unit are preventing a pulse on low voltage AC from triggering the "add" solenoid of the scan control.

remove the chassis cover plate on the rear of the machine. looking at the TSU, at the top are two solenoids. The topmost one is the 'add" -which initiates scanning.

Have someone make a selection while you observe the action, if any, on the add solenoid. If little or no attempt is made to pull up you'll need to trace out the contacts in the credit unit and make sure they are connecting, are not badly pitted and have some overtravel. Pitted contacts constitute a resistance and can lower the voltage available at the coil.

As far as the inability to pull a selection, that may be related to the CU -but there are number of other possible causes as well.

If a selection has been registered and the machine is able to read-out they should play once the add solenoid is pulled up manually (be careful full line voltage on the contacts) and service sw is in normal -run.

The amp has nothing to do with the selection system.

Have the units been rebuilt?

Rob/NYC

Bird,
Both you and Rob, are incorrect here, if you answered my question about the service switch correctly--
"Center position" of that switch handle, is NOT "run", or "operate"--it is "off" (READ your "I & O Manual"), and in this case, the phono mechanism is doing exactly what it should. As for the scan control assembly, since you did not answer my question about how many times it scans, after starting, I can not tell if it is operating as it should or not.
I would assume that the meter has mechanically failed--in which case, I recommend strongly that both wires to it be removed, as the coil often fails shortly thereafter---which CAN cause a "no scan" problem.
IMHO, a copy of my "Seeburg Mechanism Guide" would be of help in trouble shooting your problems--PM me if you wish to purchase it-- Ron Rich

Ron, I understand the operation of the service switch. I do have 9 of these old machines on location.

It would be helpful to tell the original questioner of the three positions of that switch.

The canter is indeed "Off".

The spring loaded position is to start the mech travel and add credits manually.

The far opposite is the "normal" "Run" position.

I agree that a shorted play counter could kill the scan pulse without blowing what little fusing those machines have. However since it was aid that the machine deducts credits normally I didn't suspect that was the cause.

There are probably several things going wrong here.

Rob

Hi Rob,
Whatzamatter ??--can't take a joke today ?? I know very well that you know how the service switch works--I was just "ribbing you"--
How some-ever, The fact that he "feels" a pulse on the meter indicates that it has already deducted the credit--it does this first ( with the same "stroke" of the "cancel coil"), then pulses both the meter and, if the service switch is in the "operate position", ONLY, the scan control start solenoid. Ron Rich

Ron & Rob,

The service switch is as Rob described:

SCAN OFF RUN(normal) [Manual Credit Switch]

When I cleaned off all the contacts in the USPU1 (bottom, and all the others), and put the switch in RUN when I made the selection, the mech scans!

Now to dig into the scan twice, and stops problem.

Hi Bird,
If you had the paper label that went with the switch, they called the right hand position "operate"--
What you need to do now, is determine if your non-pickup problem is in the read-out, or write in sections of the phono--the simplest way to do this, is to use a known good D cell "flashlight battery". Remove the RCA type plug from the TPA, ground the + side of the cell to bare metal and touch the tip of the RCA plug to the bottom of the cell for a second. Return the RCA plug to it's socket, and start the mechanism scanning, either by making a selection, or, using the scan switch (remembering to put the switch back to operate !). If the readout/sense/trip circuits are good, it will detent at each and every record space, on both sides-let us know what happens, and we can go from there- Ron Rich

Ron,
I tried putting the center of the plug to the + , tested, and then the - side of the battery, and grounding the opposite - Mech scanned and did not pickup.

"17AY-B" test failed.

"17AY-L" [a->b] selects {see 19 or 24 of TSU3)

(19) Weak 12AX7 (replaced with 2 different tubes)
(24)Defective Pulse Amplifier (replaced cap and resistors a few weeks ago, 17AY-L did not select before rebuilding.

<> Removing 12AX7 while scanning causes trip.

Hi Bird,
Unfortunately, I find the trouble shooting guide to be useless at this point in time, as it was written when that system was new, and they did/could not take the 50 or so years of "punishment" into consideration-
I would start by checking all voltages shown on the schematic--if good, I would then check the RCA plug to be sure that both a "colored wire" (usually green), and the shield, were still well soldered to the outside ring portion. If so, I would check the resistance, tip to ring of that plug--should be 1.5 to 5 ohms. If good, I would check the 5 amp fuse soldered to the front of the mechanism. If it "looks" good, check it with a meter. If it looks bad (black) do not replace it--find the short first--it's usually in the reversing switch, between the 117 vac, and the read out circuit. If all's still OK, check the 4 pins in the contact block ("frog") that ride the TMU--be sure all wires are attached--meter check is required, as sometimes the plastic coating on the wires stick to the pins, but the wire itself, is broken underneath. Check the pins themselves--they must have silver left on the tops, and they must be smooth on top--not "gouged out". Next, check the detent switch--It must not be "pitted/dirty", and it must have silver left on the points--then adjust it as per manual. Check the 100 mh. choke on top of the detent switch--3-5 ohms resistance is fine. If all that's good, you problem is in the TSU "electronics". Ron Rich

Thanks Ron,

I will check into all those.

--BB

In addition to Ron's suggestions, you can get a good idea of how things lay by connecting a typical neon test lamp from the two test points as shown in this simplified schematic:

http://www.fileconvoy.com/dfl.php?id=gf ... e662c63ed3

Connecting the test lamps from the junction of G & H and chassis the lamp should go out each time the mech hits a Tormat rivet. This indicates that the readout circuit is drawing current. With mech scanning and service sw in normal run position the lamp should flash rapidly and consistently except at the ends of travel where it will momentarily stay on.

It is almost inevitable that the detent switch will need cleaning and a slight adjustment to compensate for wear on the contact points.

Looking at the linked schematic there are two typical problem points; the 56k-ohm and 36 ohm resistors which often go out of range and open.

Rob/NYC

Rob,

That is a great page, it combines a bunch of all the other pages to a simple
to follow schematic!

Thanks,
BB

Ok, well you may as well take these too:

Write-in:

http://www.fileconvoy.com/dfl.php?id=g0 ... bbb80ad12b

On the write-in schematic the 190 ohm thermistor is shown as being in the chassis. On the later units such as yours it is in the Tormat itself.

Trip:

http://www.fileconvoy.com/dfl.php?id=g8 ... cb2f577024

You first need to pass the battery (readout-trip) test before dealing with any write-in issues.

Realistically , the selection receiver and amp MUST be rebuilt or you'll be dealing with poor performance and reliability...and, there is always the threat that a shorted or leaky capacitor will kill your transformer(s).

Rob