Post by tvtechrich on Jan 21, 2024 0:40:51 GMT
I just bought a 474 that was complete and not working. Gripper was sticking so i decoupled it from the motor and got some cleaner and oil in it. Now it works smoothly but won't release the record in the basket. Gear will not advance to the point where the clamp opens, and of course it doesn't rotate far enough to drop out the microswitch. Thought it was out of time and hated tearing it apart,,,but looking closely at the steel pin that sticks out the side of the gear, the pin that stops the trunnion when it hits a stop, I noticed it was bent a few degrees from straight . Not wanting to break the pot metal by trying to bend it back, I rotated it until I could wedge a piece of steel between the end of the pin and the stopping block. Then I used a drift punch and a hammer (really) and hit it a few times until it was straight . Worked smoothly all the way now! No cracks , no looseness. Don't know how it ever got bent, unless that gearmotor had enough torque to do it.
BUT when it is turned on it immediately picks up the record from the basket ,places on TT tonearm sets on the spinning record, and blows the mech breaker. resetting it move it a tad. Now I' m thinking a weak breaker from when someone kept resetting it so I throw a 3 amp cb on and, yay 7t works..but blue smoke comes from somewhere near the pin coils. Couldn't tell which one, couldn't feel heat. By the way I never saw the basket move EVER since I've had it. Seems free if I turn the motor shaft tho.
I'm familiar with AMI pin banks, read and write, and how the stopping switches work but I have questions about this Rockola. #1.. the pins on the outer circle can be out toward the outside or in, toward the center. which way is written and which is erased ? Same question for inner circle. Thin is lookng from the sisde AWAY from the turntable.
#2..There are 2 sets of magnets 180 degrees apart on the inner side of the pin disc. Moving one either sets a pin, or resets a pin on the outer circle, and its mate does the same on the inner circle. Same setup on the outer surface of the pin disc i assume.
#3 I might have found a stopping switch about 1 o'clock near the outer edge of the pin disk but can't flex anything or see how it could operate.
If I can set pins so they don't stop the basket and figure out the stopping switch maybe I can make it scan . Sorry for the long post, I don't expect you to address all issues but any insight will help.
BUT when it is turned on it immediately picks up the record from the basket ,places on TT tonearm sets on the spinning record, and blows the mech breaker. resetting it move it a tad. Now I' m thinking a weak breaker from when someone kept resetting it so I throw a 3 amp cb on and, yay 7t works..but blue smoke comes from somewhere near the pin coils. Couldn't tell which one, couldn't feel heat. By the way I never saw the basket move EVER since I've had it. Seems free if I turn the motor shaft tho.
I'm familiar with AMI pin banks, read and write, and how the stopping switches work but I have questions about this Rockola. #1.. the pins on the outer circle can be out toward the outside or in, toward the center. which way is written and which is erased ? Same question for inner circle. Thin is lookng from the sisde AWAY from the turntable.
#2..There are 2 sets of magnets 180 degrees apart on the inner side of the pin disc. Moving one either sets a pin, or resets a pin on the outer circle, and its mate does the same on the inner circle. Same setup on the outer surface of the pin disc i assume.
#3 I might have found a stopping switch about 1 o'clock near the outer edge of the pin disk but can't flex anything or see how it could operate.
If I can set pins so they don't stop the basket and figure out the stopping switch maybe I can make it scan . Sorry for the long post, I don't expect you to address all issues but any insight will help.
