Phonoland

Hello Community!

I have a Seeburg Jukebox. My Problem is that it scans twice and isn't able to find any selection i made.
I made already the battery test and the result was the same: scan twice. So i think that the problem is in the read out circuit.

I have a SSC8. Can you help me?

Using a GOOD, ANALOG meter, check the read-out test point on the SCC. With the detent switch OPEN it should read 300 vdc, or more. If that reading is good, start a scan, by making a selection. This reading should be around 175 vdc except when reversing. Let me know what happens-- Ron Rich

Hello Ron!

Is it possible Meter the things with an Oscilloscope?

Probably-- ?? When you did the "battery thing" did you use a good "D cell", and ground the positive end of the battery ? Did you happen to look at the RCA plug--it SHOULD have two wires connected to the ring--one colored, and one braid. Ron Rich

I Took 3 Different Batteries. All the same thing.
You mean that the connection between cable and connector.

Yes the male RCA connector--

Ron Rich

So: i think the RCA connector is ok. You can persuade yourself by looking on the picture.

When the motor isnt moving the Read Out voltage is correctly at 380V. While the motor is moving the voltage dips between ca. 25 and 15V. Why?

"imazze" the reason the voltage drop to near zero is because it goes through only a few ohms at the choke and tormat. This is normal and indicates a likely complete readout ckt.

Here are the simplifieds of the readout and write-in:

http://s1192.photobucket.com/user/Rob-N ... rt=3&o=116

http://s1192.photobucket.com/user/Rob-N ... rt=3&o=117

Start the mech scanning, then tap the phenolic contact guide on the trip relay to close its contacts. The mech should immediately trip and detent. The relay should stay down for a second or two while the mech detents.

If so, it indicates the trip circuit after the SCS is OK along with the mechanical linkage in the mechanism.

Check the RCA plug from the Tormat w/ohmmeter. Typically, you'll see 2-3 ohms maximum.

Rob-NYC

If your read out voltage is going to close to zero, this indicates that either the detent contact on the detent relay, in the SCC, or the mechanism clutch switch (outer blades), are failing. I would bet on the later. Ron Rich

Ron, if he is measuring from the test link on the SCC (terms 2&3) the R-O will fall to near zero as the machine interrogates each toroid, which is what he indicated here:



Rob

Rob-NYC wrote:choke and tormat

Can you explain, what the Choke is?

Rob-NYC wrote:Start the mech scanning, then tap the phenolic contact guide on the trip relay to close its contacts. The mech should immediately trip and detent. The relay should stay down for a second or two while the mech detents.

Where is the phenolic contact guide? You mean close with an screwdrvier? When i Try this the mechanism should stop and play a record, i am right?

Should i check the resisistance from the two pins on RCA plug?


Max

Max, the choke it up at the detent switch. It is part of what shapes the readout pulse at each toroid rivet.

Where is the phenolic contact guide? You mean close with an screwdrvier?

No, Do NOT use a screwdriver on any contacts. The phenolic material is the brownish guide that pulls the blades on the relay down when the relay is energized:
http://s1192.photobucket.com/user/Rob-N ... rt=2&o=213

Slide the SCC out far enough to see the trip relay, it is a bit difficult give the position of the SCC on that model. Start the mech scanning a press on the phenolic guide, this will close the contacts and trip the mech. the relay should stay energized for a second or two due to contacts in the mech.

Should i check the resisistance from the two pins on RCA plug?

Yes. Measure from the outer shell to the center contact. Around two ohms is right. Check that no wires are broken or shorted.

Rob

Hello!

I startet the mech with the Service switch on scan. Than i tapped on the guide of the Trip Relay (this or: 2016-08-13 13.44.21.jpg ???) in my SCC. The relay stays in this position until a Took the computer power of the Jukebox.

The RCA plug has 2.8 Ohm.


NOTE: If i tap on this switch behind the motor the mech stops and plays! 2016-08-13 13.44.49.jpg


Max

Hi Max,
If tapping the "clutch switch" switch below the fuse ( shown in the 2nd photo) makes it play, that contact (formerly called the "W" ), is dirty/burnt/mal-adjusted--This makes sense from what you originally posted and would have been my next suggestion. If you are not familiar with "cleaning contacts", see above post on how to clean contacts. ( don't have a schematic of that mech handy here -- the "W" is either called the "2M-1", or the "3M-1" on that, and all subsequent models--this varies by model number of the mech.)

Hi Rob,
The read out voltage does NOT fall to near zero IF using a good (damped) ANALOG meter --it , if operating as it should, will read apprpox. 50-60% of the un-regulated supply, while scanning--It falls to near zero with an poor analog, or most digital meters. If it should fall to the low Max mentioned, while scanning (except as it reverses), that indicates the SCS has energized the detent relay and it has grounded out the RO voltage ( as it should, so the relay does not re-energize when released).
The act of the relay closing, also provides ("instant"--within 4/10 second) the detent coil ground circuit. If not grounding the circuit, either the "W" contacts, or the relay itself, are failing to make good contact (usually the "W" contacts)-- If "slow" to provide that ground, the mech will scan past selected record and detent elsewhere--distance will depend on contact passing enough current--if that never happens, you wind up with the symptom Max described). Ron Rich

Max, I agree w/Ron regarding the clutch switch contacts. The mech should trip immediately when the trip relay is tapped. However the 2M1 and 3M12 contacts will prevent trip if defective or open. Once those are cleaned and operating properly it should pass the "battery test".

Also, check the 36 ohm resistor in the readout supply. This is a common failure point due to the high pulsed voltage.

The approx 2.8 ohm on the RCA plug should be Ok. Seeburg used two sensing loop turns through the toroids to develop enough output on the SCS solid state models due to the lower gain in the trip circuit as compared to the old tube design.



Rob