Rowe AMI 1100 issue

Hi,
I'm trying to sort my 1100 mech hideaway with a WRC wall box. I bought it as a runner, but soon had problems with the search unit going round & round, this turned out to be dodgy edge connectors. It works fine now but ....

The problem I've got, is the selections S,T,U,V, numbers 0 through to nine are playing one number back, so S1 plays S0, S9 plays S8, V9 plays V8 and so on.

I'm guessing a fault like that must be quite specific. I've checked some of the (what I think) more likely settings on the search unit. I'm hoping one of you experts will be able to say straight away what it is because of the letter group?
any advice welcome.
Terry

Terry,
Hopefully Alan will respond, as I don't know, but I am curious--
Are you sure all other letters respond correctly ? Ron Rich

Yes Definately just those letters, strange isn't it. I'm just not sure if it's a wallbox issue or a mech issue. The only other thing I've done is put a different stepper in, to try to cure the first issue. (its one of those half solid state half relay units with the white plastic cover).
In fact reading what I've just written, perhaps I should tighten the blades on the edge connector of the previous stepper, and try that again.
I'll do that Tomorrow.
Terry

Nope, just been out, adjusted the edge connector on the first stepper and put it back on.
The number problem is stll there. So I guess it's not the stepper.
Terry

Hello Terry,

First of all push out the pins that you think are affected out on the search unit and scan off to make sure that the stop plate is picking these up and selecting them correctly if these are ok both on the A sides and the B sides then check out the stepper, from what you say it is an electronic version, if this is the case who is the manufacturer? If you were in the UK it would br an HGM (Hazel Grove Music) or a MHG ( Music Hire Group) Rainbow the HGM operates on 30 volts but the MHG operates on 50 volt.
It is difficult for for the layman to check out one of these steppers other than changing out some of the relays.
The issue may be on your wallbox, it may not be sending the correct pulses out to the stepper.

Please let us know how you get on with testing the search unit.
Regards
Alan

Alan Hood
ami-man
UK

Hi Alan,
I'll try pushing the pins out and let you know.
I have 2 steppers, the one that came with the machine and was working ok (label missing from the board), and the one I bought on line (HGM). The selection fault occurs with both steppers.
I did check the settings on the search unit to try to cure the original search fault, I hope this doesn't to turn out to be an own goal!
many thanks for your help.
Terry uk

Alan,
I did it the other way round to the way you suggested but I think I proved the same thing.
I took the search unit off, and made the selections on the buttons, and the wrong pins are coming out ie S1=S0, T1=T0, U1=U0, V1= V0, and on up to 9. (but just those letters)
I can't believe 2 steppers would have identical faults.
what do you think?
Thanks
Terry

Hello Terry,

Are you saying that you removed the search unit off of the mechanism and used the wallbox to select the same number you tried before?

The test I suggested would prove the operation of the stop plate assembly for the pins pushed out.

If the search unit was on a mechanism in a jukebox you could test the search unit from the jukebox keyboard.

You need to have your search unit tested and proved before you can proceed.

Regards
Alan

Alan Hood
ami-man
UK

Hi,
I've been playing about with the spare search unit, and ...
It needed all the contacts and the wiper board cleaning, and the outside select coil isn't working (what kind of resistance should I expect to find on them?) but crucially, all the inside pins, including T, and V select correctly, and the correct records play.
So, it seems to me that my original search unit has a strange fault on it. What do you think. looking on the Commutator board, the only significant thing I can see is that the ST and UV segments on the back, are common withe the 0 and 9 segments on the front.
Also do you have any tips on how to proceed with fault finding the outside select coil on the spare unit.
All advice appreciated.
Thanks,
Terry

Hello Terry,

Have you checked the restance of both coils?
They should be 14 ohms.

The tracks that supply the coils are the two thin tracks that you will see that are on the PCB both front and back and they can wear through by the wipers, if this is the case then you would need a replacement board.

Contact me off of list if you require any parts.

Regards
Alan

Alan Hood
ami-man
UK

Success!
I'm not exactly sure what I've done though. I robbed a good select coil out of the original search unit, and used the better of the two boards, re-assembled, taking meticulous care with settings and cleaning contacts, and hey presto it worked. So I thought I might as well take the edge connector off and put the plasic cover on, and re mount the stepper properly, and try it again, and guess what, search unit goes round, stops in the right place, but both select coils not working .
Another few evenings of playing about with edge connectors, swapping steppers and search unit relays, as a last resort, almost as an after thought, I gave the edge connector surface on the stepper board a rub with some fine wire wool, (although I didn't think it was very dirty or tarnished). Now it's working perfectly.
I'm just a bit nervous about disturbing anything now, I still need to re mount the stepper, and put the cover on the search unit.
Alan, I'll be in touch once I'm sure of what I need.
Terry

Hi Terry,
I am happy to hear it's working--However, IMHO, "steel wool", should never come any closer to an electronic circuit then about 50 feet ! If used as you did, it degrades the plating on the edge connector, and the small particles tend to find their way to causing "shorts" later on. I would suggest that you should use nothing more abrasive then a pencil eraser ! If the connector is contaminated with any type of "oily" stuff, either a "plastic safe-safety solvent", or liquid soap, and hot water should be used.
The pins in the plastic socket also should be cleaned. It's best to remove them, one at a time, clean them as above, "re-form", and reinsert into the housing. Replace any pin that is dis-colored. A product made specifically for cleaning the above is "Deoxit". I have found it is useful, but not at all, for "open type" contacts, which must be left dry.
Ron Rich

Hello Terry,

I fully agree with all that Ron has told you, I always only use a pencil rubber (eraser) on Search Unit PCB's , Encoders, and the early Rowe Ami credit clocks.

I use wirewood but only on woodwork that is not connected to jukeboxes at all.

If you need any parts please feel free to contact me direct.

Regards
Alan

Ok, I'm Suitably embarressed.
How do I get the edge connector wire terminals out of the plastic strip to clean them. I've tried gently tugging the wire, and pushing from the other end, but I don't want to force anything.
I've still got something funny with the search unit edge connector, segment C/D and 2 isn't working, although I'm sure it was last night (plastic cover syndrome again!!). The search unit won't stop when selections including those digits are made. This seems to point to terminal 9 on that connector.
Terry