AMI Continental 2: Will Not Select and Play Record

[jukenorman]

Looking at the schematic, I only see normally open contacts of R2. When you power the machine, the pulse control relay R2 energises (delay of a few milliseconds because of timer circuit) through a normally closed contact of the sprag relay and the contacts will close. A contact of R2 energises the latch relay, provided there is credit.

Norman.

[Deadhead Japan]

After extensive troubleshooting and lots of learning, I finally made some progress! Still checking for power at the relay, I discovered that there was no power on the left side of the relay, but the right side did. I shot continuity between all three leaf switches and it was good, so I started to zone in on why was the latch relay not getting power. I new the credit plunger was getting power because the credit solenoid was cycling when pressed, so I was concentrated on the dead side of the relay to the latch credit screws. I disconnected the pushbutton on the selector and shot continuity from both clips... Good continuity. I then shot continuity on the switch itself and discovered that I was not getting continuity on the connectors that I had terminal ends connected to. Continued to investigate and found that I had not had the terminals connected correctly on the switch. reconnected the terminals and presto,, the latch relay retracted!

I was able to write in one selection, the wipers all activated and the juke did its normal cycle. However, it will not write in any more selections. Now onto the why it won't complete the write in selection. Small victory!

[jukenorman]

Dec 30, 2023 3:23:47 GMT Deadhead Japan said:

 I discovered that there was no power on the left side of the relay, but the right side did. I shot continuity between all three leaf switches and it was good

The relay contacts have different functions and come into play at different times in what is a sequential operation, so linking certain parts may not be the correct thing to do in the overall scheme of things.

Norman.

[Deadhead Japan]

Absolutely!  Like I mentioned, a learning process!

[Deadhead Japan]

Crazy! Settled down to continue to troubleshoot why I can't make a selection. I checked for continuity from the latch bar stopping switch to the sprag relay and I have good continuity. Additionally, I checked from number/letter end switches and have good continuity there with the buttons pushed. I happened to push the credit plunger and noticed it did not cycle, through some more searching, I discovered that R2 was not being energized on the right side. I have good power on the left, hence why the latch bar relay is being energized... I depressed the R2 relay to see if anything occurs and nothing did. Ran out of time for today... Always one step forward, two steps back.

Any suggestions?

Neal

[jukenorman]

Hi Neal,
I'm sorry, I don't have any particularly constructive suggestions because I'm having difficulty following what you are doing. I don't understand what exactly you mean by "I discovered that R2 was not being energized on the right side. I have good power on the left" The pulse control relay R2 pulls in through a normally closed contact of the sprag relay provided the scan switch is in the on position - that's it. A contact of R2 then energises the latch relay provided there is credit; that circuit is also fused - have you checked the fuse? It would not surprise me if you have blown that fuse since you have been shorting across the contacts of R2.

Norman

[Deadhead Japan]

Hi Norman,

Sorry for the confusion! Sometimes a little difficult describing what I am doing without providing pictures. When I am describing left/right side of the relay, I am merely stating the left/right leaf springs and contacts. I have a schematic where some labelled the contacts by "A, B, C", I could reference the switches by that for clarity. I am 100% tracking what you are saying with regards to how/when R2 is energized. I have not checked the fuse yet, but looking at the schematic, I suspect that could be the culprit.

[Deadhead Japan]

Happy New Year! One of the 1 amp fuses was blown. I replaced the fuse, then it blew again. After an exhaustive search, I discovered that the number side end switch was continuously mated. Unstuck the switch, replaced the fuse and the machine now cycling.

My next problem has been revealed... When a selection is made, the wipers cycle to the selection, but I noticed that magazine cycles very slowly. After several cycles, I discovered that the sprag relay was energized and the switches are made. I could see a little spark. I noticed that the latch bar does not reset the depressed buttons. If I hit the stopping switch, the sprag relay releases, then the magazine speeds up to regular operating speed.

There are other problems are present, but I am focusing on the why the latch bar is not releasing after a selection is written in. I suspect that the 100 MFD cap associated with R2 is bad (have not changed this cap yet).

[jukenorman]

Hi Neal,
I doubt that the capacitor is the problem here. This is briefly how it operates -

When you push two buttons, the search motor runs. When the selection is found, the sprag relay pulls in. This "writes" the selection. A contact of the sprag relay also de-energises the pulse control relay R2 (after a short - milliseconds - time delay, which ensures a good write in pulse). R2 then drops out the latch relay R1 which in turn energises the latch solenoid, releasing the pushbuttons.

Now that the pushbuttons have been released, the circuit to the sprag relay is opened and it de-energises. The de-energised sprag relay pulls in R2 once again which will energise R1, provided there is credit - ready for the next selection to be made.


Norman.

[Deadhead Japan]

Hi Norman,

Thank you for the brief explanation... I actually copied this down from a different board you wrote on a few years ago. In my case the sprag relay pulls in, but does not release. I have observed a little smoke from the relay area, especially if I don't get the relay to release. I have not changed any capacitors on the mechanism itself. What actually causes the R2 relay drop out? Does the time delay circuit cause R2 to drop out?

[jukenorman]

A contact of the sprag relay when it energises breakes the power to R2 but R2 will stay energised for something like a further 100 milliseconds (blink of an eye!) until the charge in the capacitor depletes. The sprag relay circuit is also slightly more complicated than I described above because after it pulls in, there is a hold circuit through a 50 ohm resistor to reduce the power drawn and prevent smoke! There's quite a bit going on overall in that circuit so it's important that the contacts are set correctly.

Norman.

[Deadhead Japan]

Continental 2 Saga Continues...

Recapped the phono terminal board... The capacitors were all the original bumble bee types and all caps values were way out of tolerance. However, since I had the mech out of the cabinet, I gave R2 a really good look over. With R2 not energized, two contacts were still mated. I adjusted the leaf springs, to make sure the contacts were normally open with the relay de-energized. I am pretty sure this is what causing my problem not allowing the latch relay to to release the selection buttons.

While I had the mech out, I shot continuity from R2 contacts to all of the terminal board connections. Good continuity through out. Put the mech in, ran it up. I am able to make a selection, the sprag engages and releases, clears the latch key buttons, but that is it. The magazine does not scan to the selected pin, but the magazine does scan normally with the scan switch. The selection is being made... the pins are being pushed in. .

I can force a play by scanning the magazine up with the gripper bow, hit the stop switches and the bow will grab the record and set it down. Turntable spins, and tone arm sets down (still need to adjust landing position). The record will play and the tone arm will retract, gripper bow picks up the record and returns it to the magazine, however, the magazine does not scan after that cycle. Additionally, I verified that the playmeter is not recording a play. According to the schematic, the playmeter, selection solenoid and scan magnet are just after the PCR switches.

Before, I could trip sprag contacts with a plastic roller and the magazine would scan.

Gee whiz...The phono schematic has a .1 MFD and 100MFD listed.  When testing capacitance of the .1MFD, it rings up at 100 nf.  Is that not the same as 100MFD?

Scratching my bald head...

[jukenorman]

Hi Neal,
I would say that's a decent amount of progress! I was beginning to worry that you were becoming a bit bogged down.

Why the magazine doesn't scan when previously it did seems a bit strange on the face of it - however, maybe now is the time to replace the 100uF capacitor on the time delay circuit of R2. It may well be that you're not getting a fat enough pulse before R2 drops out to pull in the scan magnet and playmeter (now that it's working correctly). I recall a previous query on the forum where the playmeter did not increment because of this.

Capacitance - 1nF is a thousandth of 1uF (or MFD) so 100nF is indeed 0.1uF but 100uF is one thousand times greater.


Norman.

[Deadhead Japan]

Hi Norman,

I screwed up! I installed a .1 mfd in place of 100 MFD... Suspect that is my problem... the old MFD to UF somewhat confuses me!  In any event, I will order a capacitor tonight.

[jukenorman]

Yes that will certainly make a difference! Remember that the 100uF is polarised so you will have to connect it the right way or it will go pop!

Norman.