Dual Changer model 1228

Symptom: When changer is activated and going through it's cycle the arm will lift and then set back down without moving from whatever spot it happens to be in, abeit over a record or over the armrest etc.

I've noticed that the black plastic lever that lifts the arm "lift pin" also has a spot that is flat with small bumps on top that slide across another pin. This pin when pushed moves the arm until it engages the limitter conected to the record size selector. The problem if I understand it, is that the black lever is sliding on the pin but not moving it, thus not moving the arm. The arm itself is free to move and not hung up in any way. Could there be a piece missing from the pin? Say, a rubber cap to give it some grip? Or, am I looking in the wrong place for the problem? Any help would be appreciated. Thom

Possibilities:

1. The cue control is up. The 1229 was the last Dual changer which did NOT give trouble of some sort when the cue control was up during a change cycle. The 1228 was the first one which did give trouble. It went kind of nuts when the cue control was up, because Dual cheaped out and made the cue control lever also serve as the record size stop. With the cue control up, the record size stop either jammed against the arm index, or kept the arm from indexing to a record size (in which case, it went all the way to the record label).

2. The cue control is misadjusted. If it is set wrong, it will cause the same troubles mentioned above when the cue control is down.

3. Someone tried to adjust arm raising height using the screw on the cam end of the pickup arm control lever. That adjustment actually adjusts horizontal drive friction and drive release point. The height adjustment is a stop which keeps the arm from lifting higher when pushed by the raising pin. It is found above the plinth on the arm itself.

4. The pickup leads are tight.

I think the answer is behind door #3. I adjusted the tonearm height limit and viola it worked. So now I am going to clean and lube the unit and readjust as necessary to put everything back in order. Thanks for your help.