Seeburg not selecting

I have an STD3 (sounds painful I know) which starts to scan after you punch in a record number, but doesn't stop at the record. Coming to rest after two passes.

I have tried the D-Cell battery on the Tormat RCA plug and the same thing happens.

On inspection of the wipers under the Tormat everythings seems to be making contact. At least in one direction I can see little sparks as the wipers pass over the rivet heads.

The guy I bought it from earlier today thought that it could be the Tormat Unit.

Does this sound right given the symptoms, or should I be checking elsewhere first?

Keith, it is not desirable to see sparks at the tormat rivets. This leads to carbon buildup and unreliable tripping.

It won't hurt to look for a trail of carbon deposits trailing after each rivet and use an electronic cleaning solution to start the troubleshooting process.

You will need a schematic: http://68.34.134.64/Seeburg/SEEBURG%20% ... %20FC2.pdf

Check for the readout voltage on the plunger block. Place a card between the plungers and rivets, make sure the detent sw contacts are closed (on mech) and look for somewhere around 120vdc, the linked schematic should have all that info.

Remember that the solid state Tormat unit used a write-in voltage that was a -minus- the reverse of the older tube units. the battery test places the positive term on the chassis and the RCA center on the minus.

There are a number of edge connectors and headers on the control unit that can cause these problems as they tarnish and loosen.

I have not worked on one of these since summer 1992 so that is about all the assistance I can do from memory.

Rob/NYC

Guy's,
I don't think you should attempt to "place a card between the plungers---" on this model phono, as first of all--it ain't gots no stinkin' "plungers". Second, doing so risks bending the read out "finger". Read-out voltage can be tested at the front of the DCC on the test terminal--detent switch MUST be open to read the voltage, which must be 105 +.
This problem sounds as if the TMU alignment is marginal, and/or the detent switch adjustment, or "cleanliness" is poor.
Ron Rich

Ron, Keith, the reason I suggest testing for R-O voltage -at the plunger...Ok "finger block" is that this is the only way to include all the connections and switches that load or interrupt the R-O voltage between the test points on the DCC and that block.

I've had two instances, one only a month ago, where an oil soaked detent switch drained the R-O voltage but did so while the flickering/pulsing at the readout source (shown by neon lamp) appeared normal. The fact was that only a tiny amount of voltage was actually present at the plungers (a 201). One could test for a pulsed load as the mech scans at the test points on the DCC but this might not tell the whole story.

These SCS based machines require two extra sets of contacts on the mech to open the trip relay. One set called 2M1 are closed during scan and the other 3M1 are to be open during scan. Those contacts and the two sets on plugs are also to be checked.

The circuits involved are very simple and the schematic (pg's 30 & 31) makes this circuit easy to test.

Rob

I learn so much from you guys.

Keith - I have also found it helpful to read Tony Miller Symptom 3 as it helps me to understand the differences between Write Out, Read In and Trip Circuits. Although it was written generically for all Seeburgs it still helps me understand the process.

http://www.west.net/~jay/fmillera/fmill ... ptom_3.htm

ps - I see you listed the Gem on Craigslist. That's a good deal for a LS2 with front doors that are in that good of cosmetic shape.

Rob,
The "2M-1"contacts are in the trip circuit. The two "extras" ( also used in tube type LPC, and SMC "non-SCS based") models !) are the 3M-11 and 3M-12.
While I have never seen a detent switch "leak", no matter how "oily", I have seen many that were "dirty" and/or "pitted" enough that they would not pass the proper amount of current to activate the circuit.
Ron Rich

Thanks for all your help guys. I will let you know how I get on with it as soon as I am able to get back into my shop - very busy at the moment with "other" jobs.

Mark - I only repair jukeboxes as a hobby, so I like to sell them as reasonably as possible. I prefer them going to a good home where someone will get years of enjoyment from them, than charging large sums of money. Besides, now that I have 19 in stock I need to create some space!!!

Ron Rich wrote:Rob,
The "2M-1"contacts are in the trip circuit. The two "extras" ( also used in tube type LPC, and SMC "non-SCS based") models !) are the 3M-11 and 3M-12.
While I have never seen a detent switch "leak", no matter how "oily", I have seen many that were "dirty" and/or "pitted" enough that they would not pass the proper amount of current to activate the circuit.
Ron Rich

Right, the 2M1 points if not making would prevent tripping even though the readout was normal. Same with some of the plug contacts.

Personally, on a machine this old, I would try not to do a piecemeal repair, but rather a total disassemble-wash-rebuild. It takes longer but the machines are much more pleasant to work on and a lot of dirt related prob's go down the drain.

As for the "leaking" detent -Mea Culpa. My commercial machines are liberally oiled and the motor shaft slings it into the detent. After testing and disconnecting one lead from the detent sw there was no question as to the cause. Those old machines use about 340vdc on that switch and it had formed a path to ground somewhere on the laminations. I came back next day and put in a washed sw and after adjustment all was normal.

For "science" I clip-leaded the old sw to the R-O source and found the mounting screws "hot" with leakage current. I loosened the lamination and washed/soaked it in diluted stripper blew it dry and it then tested Ok...Don't know if I'll ever need it though.

i need to more sparing with the oil.

Rob

Here are the results of the checks I have made:

I checked the voltage at all the test points on the DCC with the detent switch open - results were:

1. Trip Relay = +26v
2. Read Load = +127v
3. Read Source = +127v (naturally as it is linked with 2. above)
4. Write Source = +127v
5. +27v Reg = +26v
6. -13v Reg = -14v
7. -27v Reg = -28v

I also checked the voltage at the wipers (fingers) under the Tormat, with the detent switch closed, and separated from the Tormat with a piece of paper, the result was: +127v (in both directions).

I also checked the 2M-1 and 3M-11 and they look to be okay (2M-1 closed during scan and 3M-11 open during scan).

While I had my head in the "lions mouth" I cleaned the detent switch and oiled the mech. Unfortunately, the cleaning, testing and poking around didn't change anything. It still scans twice and stops.

Keith, IF, you are using a good meter--there is a problem with the negative voltages--one should never be "high". and the other "low" ---
Ron Rich

Thanks Ron, unfortunately I wouldn't class my meter as "good". Maybe one day I will splash-out on a FLUKE or other such make.

Anyway, I have solved my problem - with the help of all of you - another big THANK YOU to you all.

While I was double checking the trip circuit I decided to pull the trip relay from my Olympian, which just happens to be next to the STD3. When I plugged it in everything started to work like a charm. Now I need to find a new trip relay, unless there is a way to fix broken ones?

Speaking of the Olympian brings me to another problem!!!! My Olympian is sat clutching a record and when it rejects it, it just picks it back up, but won't go into scan mode?

Kieth, great that you found the prob, as for the relay the first thing to do is test the impedance of the coil and compare it to the working one.

If it is open pop the cover check wires where they solder to the pins. You can carefully remove the insulation around the coil and see if any broken wire is visible.

You can probably sub a different relay --but make sure it's coil is not lower impedance than the original otherwise it may ruin the SCS.

If the coil is good, suspicion falls on the contacts and the tiny wires that couple the traveling (center) contact.

Rob.

Keith,
Use caution in exchanging relays--DCC-1, and DCC-4's use a "24" volt relay, while an unmodified DCC2, and DCC-3 use a 12 volt relay.
As Rob said--relay generally can be cleaned--simply, carefully pry the cover off, carefully remove the spring, and pull the mobile set of contacts out. Any pitted/ burned contacts will need to be filed, and then burnished with a burnishing tool--then re-adjusted to compensate for lost material--this can only be done once, as there will not be enough contact point left after that. New relays are available--I stock them.
Ron Rich

Wow, Ron I think I just dodged a bullet!!!

The relay I took from the Olympian was 12-volt and the one from the STD3 was 24-volt.

Funny thing is, I have replaced the 12-volt relay from the Olympian with a 24-volt relay from my SQS160, which has a DCC4 like the STD3, but now the jukebox just scans twice and does nothing again.

Keith,
If you power it off,and back on, and make a selection does the relay energize ?
If so, either the relay contacts themselves are "dirty", or the 2M1 contacts are dirty, or the wiring in between (plugs/sockets) is open -- Ron Rich