Rockola/460 problem
Posted: Mon Jun 11, 2007 9:26 pm
Any ideas why this unit doesn't sense the end of record? The record just keeps turning.
There should be a trip finger on the arm shaft under the turntable base. Since I don't know which kind of trip your unit has, I will describe both kinds.
The position trip closes a switch when the arm gets to a certain point on the record. Usually on a jukebox, the trip finger touches a very sensitive switch, or causes some sensitive mechanism to move parts to close a switch.
The velocity trip has the trip finger loosely coupled to the arm shaft through friction. A stud on the rotating turntable pushes the trip finger away from the spindle once per rotation. If the arm moves farther than 1/8 inch before the stud can push the finger back, the finger trips the switch.
Here are some possible causes for trip failure:
1. Dirt in the trip mechanism.
2. The sensitive switch is bent.
3. The trip finger is bent damaged.
4. The tonearm is ungrounded (One kind of trip finger needs to have a ground connection to work).
5. Oil in the friction connection (velocity trip).
6. Misadjusted trip point (position trip). The screw is on either the trip finger or the trip switch.
7. The stud which resets the position of the velocity trip finger when the arm swings away from the spindle is missing or damaged.
8. Trip circuit damaged or has no power.
9. The trip relay has failed.
10. The control unit is not advancing to the portion of the cycle that takes the arm off the record.
11. The arm cycling motor has failed or has no power.
12. Loose drive coupling between the motor and the arm cycling unit.
13. Loose or broken parts coupling the pickup arm and the arm cycling unit. This often happens if someone grabs the arm while the cycling unit is trying to drive it.