AMI H 200 selection problem

[tvtechrich]

Hi. My model H200 worked fine until a week ago when it started playing the wrong songs. Thinking the clamp had slipped that fastens the shaft to the pin pusher ass'y, I loosened it, lined it up with A1, tightened it and tried it out. All songs select as they should thru H 20. All J and K result in an H selection.  

I checked the button switches, thru to the letter stepper in the pulse converter, and the proper pulses are advancing to the J and K position of the letter position, but the sprag wheel stops the mech at H.
I'm starting to wonder if my initial problem wasn't from a slipped clamp but something else.
Seems strange that all works except J and K though.  I can't see the backside of the letter stepper in the pulse converter,and really don't want to take it off as it's complicated.  I don't know if an open at "J" would make it select "H" or a short between hjk would do it.
Any thoughts? Same as G200 I believe.

[Ron Rich]

From my great, but not too long memory--- The H and I models are exactly the same (other then cosmetics). Watch the operation of the two "step-up wheels". Either a short, or, and open, I think could cause that to happen-- Look at the wheels and see where they stop if you make a "J" selection as opposed to one prior, and one after. If they are reaching their respective (different) stops, I would think that something has fallen down into the wiper, or wiper disc. Is the cover on that unit ?? Ron Rich

[tvtechrich]

Thanks for the input. Yes the letter stepper goes to proper position(s). Wiper connects to j or k term but somehow always triggers at H. Going to disconnect wire on letter stepper and see if h still comes up, then I'd know it's not related. Can't see how it could be in the number unit as all digits select right. Wish I could see the backside of wiper board better.

[Ron Rich]

Oh ? Is it perhaps "triggering" too soon ?? If not, I would guess the letters are somehow/some where "shorted together" ? Ron Rich

[jukenorman]

I think there must be a short - strange that it's across three connections H, J & K though! The letter stepper commutator is wired to the letter switch commutator (at the back) so there is a possibility that you have a sliver of something conductive where it shouldn't be or the wires are bare somewhere and touching?
Norman.

[tvtechrich]

FIXED! After all this it turned out the letter stepper wiper arm had slipped on it's shaft and come to rest on 2 positions from home. Looked right to me but was starting counting from C not A. I feel dumb.
I had repositioned the pinpusher arm to make A1 and all the others on track, masking the true problem.

After moving wiper and tightening clamp, All selections now work. Well they did till I accidentally knocked the top
off the reset magnet while holding it down with a screwdriver to keep it in place while adjusting the end play of the wiper. Looks like a nasty job. Thanks for all the suggestions.Rich

[Ron Rich]

Hi Rich,
Who-ed of thunk ?? So, it waz a "short" --just not the kind we normally think of ! Glad you got it ! Ron Rich