AMi I200 Electric, Selection Woes

Hi folks,
Hope someone can help here. I've been working on this problem too long and I need some guidance please. I have the manual, "Credit & Selection System" so here goes;
When a selection is made, two things seem to happen, quite randomly. Either I get the record to the left, example, I select A1 I get K20... always the "B" Side of the previous record, sometimes it will correctly select two in a row but alas, it reverts back to the previous state. The other problem I'm having is that the stepper seems to stutter, activating the sprag relay prematurely so a pin is pushed then the search starts up again and the sprag relay energises yet again, this time the "almost" correct selection as mentioned above.... all I've done to date has not remedied the problems, I've burnished, cleaned, adjusted switches with very little success. I've followed to a T the adjustment procedures for the pinpusher, letter & number steppers, contact blade position & pressure, pulse generator adjustments as well as the converter etc. I'm up against a wall here, thumping my head firmly... aaarrrgghh.
Please try to understand my description here and hopefully make some sense of what I've tried to describe, thank you.

Sorry Steve

Steve, change the electrolytic capacitors in the stepper-search unit.

Unlike Seeburg's Guardian stepper, where copper slugs provided some of the hold-in delay, AMI's telephone type relays relied on loomed capacitors .

There is a good chance this will fix the wrong pin problem too -although that might be due to work stepper teeth. I hope not, they are really hard to find.

Rob

Rob-NYC wrote:Steve, change the electrolytic capacitors in the stepper-search unit.

Unlike Seeburg's Guardian stepper, where copper slugs provided some of the hold-in delay, AMI's telephone type relays relied on loomed capacitors .

There is a good chance this will fix the wrong pin problem too -although that might be due to work stepper teeth. I hope not, they are really hard to find.

Rob

Hi Rob, long time no "hear", thank you for the reply, if the electro's you mention are mounted on the terminal strip, I've done that. The only electrolytic I've noticed that I didn't replace, is one little yellow one on the pulse converter relay bank, furthest left, the "pulser relay". I'm wondering if that would be the root cause and now I'm scratching my head as to why I didn't replace it in the first place, like I'd normally do. Will check again and post results but in the meantime, any further input is greatly appreciated.

Cheers, Steve

Steve, check the wiper on the pulse gen (keyboard) and make sure each contact on the gen wafer has continuity with its key on the keyboard. A broken wire to a contact on the wafer can confuse the stepper into starting either transfer or write-in at the wrong time.

Rob

Rob-NYC wrote:Steve, check the wiper on the pulse gen (keyboard) and make sure each contact on the gen wafer has continuity with its key on the keyboard. A broken wire to a contact on the wafer can confuse the stepper into starting either transfer or write-in at the wrong time.

Rob

Rob,

As always, sage advise. I did check for broken wiring but the sad part of this whole affair now, is that the juke has been picked up by the client with that issue still unresolved, he wanted it back even if it was only here a couple of months, I know I know... boo hiss. I did however, (just to flatter myself here), resolve several other issues the juke had that caused it not to play all. Also, several key elements such as TT mounting plate skewed/tilted down left to right, tonearm adjustments way outta whack, tonearm wiring not correct, (stiff AV cable used), trip switch replaced with open blade contacts, etc. etc. All of the low voltage wiring, in a previous repair attempt, was bound back together with wire ties, not the original string. This told me someone went to a great deal of trouble to isolate perceived problems with the low voltage wiring throughout, not the original brittle zip or lamp cord wiring, (that issue was already addressed and newer wiring installed).
All told, I had roughly 20 hours sunk into this beast of burden and the client was aware of the remaining problem and said he could live with it for now but as far as my two cents, I hate to have to relinquish a machine that needed further service, not my style, I much prefer finishing what I started, no matter how challenging this work can be!

Thanks for help Rob, I really appreciated the pointers.

Cheers, Steve

I had a similar problem with my I-200 years ago & a very nice older juke tech we had here in Australia told me that the relay tops actually over time become "magnetized" and cause they open and close so quickly they "jump" a small amount enough to close the circuits whilst pulsing and inadvertently select the wrong selection.. The way he tested for this in front of me was to slide a piece of paper between the top of the coil and metal relay top and try selecting... the machine acted faultlessly after he did this.. showing that this was in fact the problem..

He fixed it by using a rather large demagnetizing wand (used on old 2" reel to reel tape machines) on the top of the relays and low and behold, problem solved... This guy knew his stuff and after that, I never had a problem.. the machine has long been sold and I know the buyer.. its still working perfectly.. that was 13 years ago!

It's only physics he said, a piece of metal being pulled down by magnetic force from a coil will eventually become slightly magnetized..

Anyone else heard of this fix?

Rusty

He fixed it by using a rather large demagnetizing wand (used on old 2" reel to reel tape machines) on the top of the relays and low and behold, problem solved...
It's only physics he said, a piece of metal being pulled down by magnetic force from a coil will eventually become slightly magnetized..
Anyone else heard of this fix?

Before sending out steppers and other relays, I use this:
http://s1192.photobucket.com/user/Rob-N ... rt=2&o=184 I have a small probe-type for degaussing tape heads which can be used on individual pole cores.

These are leftovers from my work in broadcast and recording...among the few things still useful.

Rob.

Steve, what you describe is a perfect example of why i don't get involved with home repairs.
These machines have generally been neglected and ofter tinkered with by some guy who thinks himself "handy". The worst messed up machines I ever bought came from homes. I'd take an Op's dumper from a warehouse or garage over one in home service.

Two weeks ago I had a message on my machine from a guy who had seen one of my large retro systems out in Queens. I ask my location NOT to give out my phone# but a few times a year someone does. I didn't return his call, but he got me a week later. I explained that I'm not set up to deal with other brands ( he has an R-O) and don't do repairs.

He then asked about a guy in Brooklyn. I've heard this person's name and one location owner had used his services for a machine he has at home. The same person told me that this "tech" had shown him how to "clean up the machines" --USING WD40! Obviously, this isn't somebody I can recommend. So I couldn't help the caller at all.

I always feel bad about refusing these requests 'cause I know how bleak the situation has become in finding competent repair people. All the old characters I knew years ago have gone to "jukebox heaven", and the younger operators, what few exist, don't know or care about these ancient machines. The best advice I can give is to peruse these sorts of forums or buy from a dealer who offers a warranty.

Other than those depressing comments, at least you can say you moved things along towards a full repair. Too bad the owner wasn't more patient. He'll probably be calling you again when he gets tired of it collecting dust.

Rob

Rob-NYC wrote:

He fixed it by using a rather large demagnetizing wand (used on old 2" reel to reel tape machines) on the top of the relays and low and behold, problem solved...
It's only physics he said, a piece of metal being pulled down by magnetic force from a coil will eventually become slightly magnetized..
Anyone else heard of this fix?

Before sending out steppers and other relays, I use this:
http://s1192.photobucket.com/user/Rob-N ... rt=2&o=184 I have a small probe-type for degaussing tape heads which can be used on individual pole cores.

These are leftovers from my work in broadcast and recording...among the few things still useful.

Rob.

There ya go!