Bingo Overhaul
Step 9: back door stuff
magic ring |
| stepping unit |
|---|
Here is a typical stepper unit. It's not too bad...a little buildup on the contact plate, but the stuff other side looks very good, so this time we'll just clean the contact plate side.
Before doing anything, step up the unit all the way and reset it using the coil plungers on the other side. The unit should step all the way up without the return spring getting so tight that the unit won't easily make it the last step. Likewise, the unit should easily whiz back into the reset position. Also, make sure the unit will reset when stepped up only once.
What normally happens is a buildup of crud on the contact plate causes the reset to be sluggish. Just cleaning the contact plate fixes this. However, if someone got happy with WD-40 on the coil side, take the whole thing apart and clean all the pieces...including inside the coils. There shouldn't be any lubrication in the coils. Another section of the site will have the diagram of a stepper, but it's pretty hard to put it together wrong - except pay attention to the reset stop. There is a post on the back of the ratchet that stops the unit from rotating further once it has reached the reset position. If you get the post on the wrong side of the stop, the unit can't step up!
The other thing to check is the fine wires on the wiper side (if it has
them, like this one does). Sometimes the wires break where they are soldered
to the wipers.
