Rockola 459. Record stops before completion.

[Paul]

Hi Folks.

Not sure if my previous post was successful in its delivery, but thought I would try again and ask for your help. 

My Rockola 459 has been performing very well until the past few weeks.


PROBLEM

• There seems to be several problems stemming from the main problem. I will try be succinct, clear and not be too wordy.
  
  
  

• Selected 4 records for play. The first two records played to completion and returned to their place in the carriage.
• Next record was selected, placed on the turntable and played for a short time, then stopped before completion.

I tried the following to correct the above

• Switched off all power.
• I noticed that the lower external spindle of the mechanism motor was very difficult to rotate. Eventually freed it up to rotate in both directions.
  
• Started up JB, record resumed play. All was good. 
• This state of play continued for the next few days, then above problem returned. 
• Made use of the Mechanism button, record played each time, but stopped after a few seconds. This method seemed to give same results as the freeing up of the motor external spindle.
• The only way I could return the record to its position in the carriage was by manual rotation of the spindle. Finger tips are now a bit sensitive .

REMOVED MOTOR

• Eventually removed the motor, removed cover plate and very lightly greased the cogs.
• Re-fitted motor. External motor spindle free to rotate in both directions
• Selected records resumed play, all ok then, above problem came back!

CURRENT SITUATION.

• I can get the record to play for a few seconds, if I rotate the external spindle of the mechanism motor or, use the Mechanism button located at the circuit breaker housing.
• I have noticed, that each time the problem occurs, the motor spindle is free to rotate in one direction only. However, with some manipulation of the spindle, I was able to free up both directions of the spindle.
• The reject button will not work, hence use of manual method above.
• With the record manually returned to the carriage, I've noticed that if I position the lever of the "Service Scan Switch" to scan, and held it in that position, the last record is selected and placed on to the turntable, plays for a few seconds,  then the above problem returns!

Totally confused.

Many thanks and greatly appreciated for any help.

Kind regards Paul

[jukenorman]

Hi Paul,

"played for a short time, then stopped before completion" - are you saying the turntable just stopped rotating mid record?

"the mechanism motor was very difficult to rotate" - do you mean the gripper motor?

"Made use of the Mechanism button" - what do you mean by mechanism button (on/off/scan switch maybe?)? It really helps if you can use the descriptors used in the service manual.

Norman.

[Paul]

Hi Norman. Sorry for the delayed response. I answer to the above:

"played for a short time, then stopped before completion" - are you saying the turntable just stopped rotating mid record?----YES

"the mechanism motor was very difficult to rotate" - do you mean the gripper motor?----YES

"Made use of the Mechanism button"----. No Norman, "not the on/off/scan switch". Located to the left of the power supply are 3 "circuit breakers, Mechanisms, Selection system, and 25 Vac power.

On activating the mechanism switch, record play begins, but then stops within seconds. In some cases, several records will play to completion, then stop again etc.

Thanks Norman.

Paul

[jukenorman]

Hi Paul,
The "mechanism button" is what we normally refer to as a circuit breaker. You might also think of it as a resettable fuse. And as we know when fuses blow, they do so for a reason and by so doing they are preventing further damage. So the circuit breaker is tripping for a reason and you really need to find that reason. Which CB is tripping, is it the DC one?

Norman.

[Paul]

Hi Norman. Thankyou for your response. Again, apologies for not responding sooner. Working through some home/personal issues.

There seems to be several issues with the above problem.

1. Record selects, plays, stops before completion of play. If I use the Mechanism CB, record resumes play but only for a few seconds, then stops. However, if I rotate (clockwise/anticlockwise) the lower external spindle of the gripper arm motor (free up the rotation of the motor as it seems to stick), record resumes play, either to completion, or stops after a few seconds---
2. If the record plays to completion, it does not reject, either automatically of manually.


The mechanism CB is the only one I've needed to use.

Thanks Norman

Paul

[daijiiwata]

I am currently repairing the same R,O,459.
The issue with the CB trip has been experienced on a different R,O,451.
I suspect the root cause to be gunk buildup due to old lubricant.
As a premise, the record transfer function area has many mechanically linked sections, making it more heavily loaded than other areas.
It is crucial to remove these and reduce the overload on the motor as much as possible.
I believe that doing so will allow us to avoid CB trips.