450 rockola mech stops when tone arm touches record

[frank]

Hello All
The 450 rockola I am working on stopped when the tone arm touches the record
According to the troubleshooting manual, it says that the 15 ohm resistor is open in the control box
I unsoldered the resistor out of the circuit and it tests fine.
Is it possible that under power it fails or could something else be the problem?
Thanks
Frank 
Ontario Canada

[jukenorman]

Hi Frank,
This is a similar scenario to what you had with your other Rock-Ola. You'll need to check out what's not happening by following the schem-a-grams, more information is required to narrow the problem. For example is the interlock release coil being operated? Also, maybe the transfer motor and/or the gripper arm assy itself requires cleaning and servicing - might the motor be stalling when the slowing resistor comes into circuit?

Norman.

[frank]

thanks Norman
I am on it
The clue is that the miniature breaker does interrupt when the write in section scans and I have to reset it
Could very well be a cleaning issue
I did notice the interlock relay moves very slightly when engaged, thought there should be a more definite click
Thanks as always
I will persevere
Frank

[jukenorman]

The write-in motor is AC powered and all the read -out circuits are DC so there should be nothing in common. The reason I was interested in the interlock release is that I thought that maybe micro switch #3 might have been operating early? But I think a good lubrication of the gripper arm assy and cleaning/lubing of the gripper motor is probably where to start.

Norman.

[frank]

Thank you Norman
I will keep you you posted

[frank]

Hi Norman
Embarrased but glad problem was solved
The idler wheele was caught under the truntable - no wonder it stopped