Seeburg SL-100 Not selecting

[nigelr2000]

This one is driving me mad, initially it had not been used for about 10 years as it failed to select any records with the sans twice no selection fault. Initialy there was no write in volts, I got the write in circuit to work after replacing a few components, a fuse and lubricating the write in switch as it was jammed with old grease so all good there. After this it happily selected records for a couple of days. Now it has stopped again and just scans twice no selection. I have scoped the write in and can see the pulse happen. I have checked the dc resistance all the way from the solid state unit to the tormat return and get 180 ohms ish with all the relevant switches held in the right position. I have checked continuity of the read out circuit and the volts and all appears good. I can trigger the selection relay to play a record with a 1.5 volt battery so all those bits are ok. Now in the service notes it says you can wire a battery to the sense loop and it will set all the toroids so it will play all the selections one by one.....this doesn't happen. I am getting 1.5 ohms continuity on the sense line measured at the plug with it disconnected from the solid state unit which sounds really low to me. I would like to have a look inside the tormat but have no idea how it comes out and don't want to break it. Does anyone have a solid state Seeburg that they can pop the plug out and measure the resisitance for me just to prove if the resistance is normal or not. Also any pointers would be helpful. I have done quite a few jukes (rock-ola's, NSM's and Wurlitzers) but never had a Seeburg with a tormat fault before

[vidjoman]

Tormats are usually very reliable. Taking it apart could damage the fine wires inside. As far as I know faults are normally within the wiring, dirty plug contacts, dirty contacts on the bottom of the tormat or faulty resistors/caps in the control unit. Unfortunately I don't have one to measure for you.

[julie_m]

I just happen to have a Seeburg ESL-100 in my front room, recently returned from storage. I'll have to move a few things around to get it in a position where I can get inside it (and then I've got to dig out my oscilloscope, wherever that is .....), but I'll try and get a good look at the signal on the sense wire.

If you can trip the mechanism into PLAY by applying a voltage pulse to the Tormat Control Centre, but you get nowhere magnetising all the cores using a battery on the sense wire (don't forget: valve and solid-state Tormat Control Centres used opposite polarity, and the latter passed the sense wire through three times a.o.t. once) that mostly exonerates everything downstream of the read-out wire (unless component value changes have reduced the input sensitivity somehow) and suggests a problem with the read-out side; it could be the read-out voltage supply (which has to put out more oomph than the write-in supply: there is only one read-out wire per core, a.o.t. one "letter" and one "number" write-in wire, and it needs enough milliamps to change the magnetisation of the core it passes through all by itself) or the detent switch (which times the read-out pulse, so the carriage will not have moved past the wanted record by the time the trip solenoid fires).

[nigelr2000]

Thanks Julie. I am getting nothing scoping the sense wire while scanning. Also not setting all the tormats to trip with a battery. I am getting over 300 volts on the fingers that scan the tormat bottom. Where is this detent switch the service manuals not that clear on it's location.

[julie_m]

The detent switch is on the carriage, and it's what gives the distinctive Seeburg scanning sound as it closes once per record-- but I'm afraid I have been lucky enough never to have had to touch mine, so I can't describe it any better!

Have you got an analogue meter capable of measuring 300V? Or can you arrange an oscilloscope with enough attenuation to see the read-out supply? It should sag noticeably while the carriage is against the record rack (it gets pulled down briefly by each read-out wire as it makes contact), then bob back up to full during the over-travel at each end. (A digital meter can't respond fast enough to show this happening.) If the voltage does not drop with each read-out pulse, there must be a poor connection somewhere. You may have to resort to following the wiring and buzzing it out to find the fault.

Also, did you try the battery both ways around? Valve and solid state Tormat Control Centres worked on opposite polarities, so you might have been inadvertently clearing the lot as opposed to setting them. And then you would not see any sense pulses; because the core would already be magnetised in the same sense that the read-out current was trying to magnetise it, and you only get an induced current with a change of magnetic flux.

[julie_m]

O.K., I just measured the resistance of my sense circuit as 2Ω.

Then I tried to get a 'scope on the sense circuit; but unfortunately, whenever I tried a double adaptor in the socket, it started playing random selections. And now, to add insult to injury, it's gone and got stuck, not tripping at the end of a record. And before that, it tried several attempts to start playing a record, which suggests "gunked-up clutch" -- especially with the trip fault. So that's going to require some field-stripping and re-lubrication, another day.

So much for Seeburgs being reliable ..... But in fairness, the machine is almost as old as me, and I don't think I can move quite as freely as I could when I was a baby .....

[nigelr2000]

oops sorry to cause you this trouble. At least I now know the trip circuit is only a couple of ohms, perhaps it got a bit insensitive as mine doesn't trip when the plugs disconnected or connected. I have a philps DVM with a bargraph along the bottom so can see the read volts popping up and down as it scans. Quite a handy feature on this meter.

[julie_m]

Oh, don't worry about it; I'm not holding it against you. The machine would have packed up anyway, the next time it was turned on; and this is a bit less embarrassing than it breaking down in front of a visitor, especially one already convinced it was an ancient piece of junk!