AMI JBK 120, Year 1960, Cerial no.520032

Is there any kind of good advices out there?

THE PROBLEM:
When doing a selection from B11 and up to B20, the result is that the pin-pusher arm is going round and round without pushing any pins. The only way to stop it is to turn off the box.
All the other selections from A1 and up to F20 are working find.

Does anyone know where I have to start searching for the reason of this problem?

Nils

Hello Nils

That is very unusual. I could understand if a whole group of letters or a whole group of numbers would not work. In your case, one half of Group B will work, but the other half will not.

The only possibility that I can imagine is that the wipers on the back side of the contact plates in the pulse converter are not correctly adjusted or dirty. For the letters, there are two wipers. One connects the letter segment to the outer ring for the numbers 1-10. The second wiper connects the segment with with the inner ring for the numbers 11-20. This second wiper obviously does not connect in the area of the segment B. You must now find out why it is so. I suspect that segment B is dirty or oxidized at the point where the wiper is running. Perhaps the wiper has too little pressure against the contact plate.

The wiper must also be adjusted exactly. I hope you have a service manual where the procedure is described.

Best regards - charly49

Hello Nils
I had the same troubleshooting otherwise. The Problem by me was A 1 To K 9. Valiant told me to clean the contacts in the selection Area that was helpful.

You can find the help here.
[forum.jukebox-world.de]
I hope you understand my English and know what i mean.

Gruß Hans Peter

Hello charly49,

You have right.
The reason of the problem was dirt on wipers.
After I clean all contacts in the "Pulse-converter", everything was working fine.
Thank you for the good advice.

Best regards
Nils