Arcing Detent Switch Contacts?

[wilitrun]

Hi All,
133S6 mech installed in a SS160. I saw something unusual that doesn't seem to be described in the Service Manual or Troubleshooting Guide today while working on my mechanism that I thought I'd pass along.

The Detent Switch has what appears to be a surge suppressor installed along the top of the switch stack. Somehow it had gotten pushed into the carriage housing so that one of the legs was making contact to the casting. This was resulting in the detent contacts arcing whenever the carriage was scanning right to left. Pulling the suppressor out of contact with the carriage cleared this issue. Hope this helps someone.

[jukeboxmarty]

It's not a suppressor, it's a choke.

The choke is a critical component of the 'write in' circuit.

Having the choke shorting to the chassis can cause several different issues... so removing the short is a good thing!

[wilitrun]

Hey guys, one related question I still have.
So the arcing has come back, this time I think from dirty contact tips. I've noticed that after scanning, the carriage comes to rest in random places just due to inertia and mechanical switches just not being razor-sharp precise. Sometimes it rests in a position where the detent switch contacts are just barely making contact, and will just continually arc until I rotate the motor shaft by hand to open the contacts up. How do we solve for this - is there not supposed to be power going to the switch when the carriage is at rest, or is this normal?