Rock-Ola 459 just getting started.

[jukerocks]

This may or may not help, but I recently had issues with the readout hammers on my 464 (essentially the same, inside). I resolved this eventually by cleaning all the contacts in the Control Box relays (burnishing tool, contact cleaner, the Deoxit). Problem solved. Good luck.

[Ron Rich]

Patrick,
Not what I would recommend ! IMHO, "Contact cleaner"/Deoxit, does not belong on make-break contact points--see the FAQ's post on contacts. Ron Rich

[jukerocks]

Ron: just because it worked doesn't mean it's the best way to do it. Thanks for pointing me in a better direction.
Patrick

[TCW]

Apr 13, 2021 9:50:32 GMT jukenorman said:

The K6 coil shouldn't be released until the ADR operates. What happens when you choose 2 as the first digit, do both hammer coils operate?

Norman.

Hi Norman,

If I choose a 2 as the first digit it will operate as it should playing a B side. This issue only occurs when play an A side or a 1 as the first digit.

[Ron Rich]

That would in my tiny mind, tell me it's a stuck closed relay contact -- I would follow the circuit back from the coil to the point that connects or, disconnects it, from the circuit. Ron Rich

[TCW]

Hi Ron, I explain where I did that in post 20. K6-1 is that point (ice cube relay). The coil for K6-1 either turns off to quickly or the wiper for K6-1 stays energized to long.

[jukenorman]

The K6 relay should stay energised until the ADR operates. There is a delay on the ADR to ensure that a fat pulse is delivered to the hammer coil. I think that your DC supply might be poor and what is happening is that the inrush to the hammer coil is dropping the DC to such an extent that K6 is dropping out - but before it drops out, a half fat pulse goes to the A side hammer coil. After K6 drops out, a half fat pulse then goes to the B side hammer coil. This is all happening in milliseconds, of course!

You should be able to see the DC drop with a good analogue meter (if it is indeed dropping?) but it actually might be as quick to just change the electrolytic capacitor in the power supply. I believe the value is 1,200uF (I don't have a 459 manual); it would do no harm to increase this to 2,200uf which would be about the same physical size as the original.

Apart from that, I cannot really see any other logical reason for K6 dropping out other than an intermittent connection and that looks less likely?

Norman.

[TCW]

Apr 15, 2021 8:35:17 GMT jukenorman said:

You should be able to see the DC drop with a good analogue meter (if it is indeed dropping?) but it actually might be as quick to just change the electrolytic capacitor in the power supply. I believe the value is 1,200uF (I don't have a 459 manual); it would do no harm to increase this to 2,200uf which would be about the same physical size as the original.

Norman.

I'm thinking this must be the cap your referring to.

[TCW]

A friend of mine is dropping off two Chengx 1000uF 50V 13X25 +/-20% -40 to +105°C 10PCS Aluminum Electrolytic caps on Sunday. I will install them in Parallel with the combined value of 2000uF 50V. I look forward to seeing how it goes.

[jukenorman]

Hi,
That was the capacitor I was referring to, but studying the schematic you posted - it should have been the 100uF capacitor to the right of the one you circled (on the +33V DC rail) that I should have indicated. You could do both since they are the original components. There is less in common between K6 and the write-in voltage than I initially thought but that K6 relay is holding from when the first selection button is pushed until the write-in is executed so I would still be very suspicious of the power supply and these elecrolytics - and you have to do something to attempt to eliminate your problem and the power supply is always a good place to start, I find.

Norman.

PS I hope your friend might also have a 100 or 150uf capacitor!

[TCW]

Not a problem but it looks like Monday now. In the meantime I finished recaping the amp to my AMI 70-120.

[TCW]

Apr 15, 2021 19:07:04 GMT jukenorman said:

Hi,
That was the capacitor I was referring to, but studying the schematic you posted - it should have been the 100uF capacitor to the right of the one you circled (on the +33V DC rail) that I should have indicated. You could do both since they are the original components. There is less in common between K6 and the write-in voltage than I initially thought but that K6 relay is holding from when the first selection button is pushed until the write-in is executed so I would still be very suspicious of the power supply and these elecrolytics - and you have to do something to attempt to eliminate your problem and the power supply is always a good place to start, I find.

Norman.

PS I hope your friend might also have a 100 or 150uf capacitor!

Hi Norman,

I replaced both the 1200uf and 100uf (Diode Board) caps in the DC circuit and because I was right there in the neighborhood also the 100uf cap on the Cone Board. The end result was no difference. I selected 100 and it played 210 and when complete it played 100. 

I don't want to add confusion at this point but I stopped typing and went back to the unit because in the back of my mind I didn't see the bulb flash when the carriage stopped. Apparently after it played the last selection it returned the record to the carriage and went to the home position and the turn table remained on and the Mechanism Breaker popped. Upon reset the turn table just spins for 10 seconds and the Mechanism Breaker pops again. If I put it in Scan the turn table runs and if left on the Mechanism Breaker pops.

SEQUENCE No. 21
RECORD RETURNED TO MAGAZINE

As the gripper jaws begin to release the record into the magazine, No. 1 micro switch is cammed to its original position. Reverse relay relaxes and places a dynamic

brake on the gripper motor ....at the same time, a circuit is again completed to the magazine motor causing the motor to run.

Magazine, selection lite wipers and "read-out" carriage start to rotate. Indicator lites "flash" across selection lite box.

SEQUENCE No. 22

SCAN CYCLE COMPLETED

When rotation of the homing wiper enters the ring opening, circuit to the play control relay is disconnected, turning off the mechanism power (THIS DOESN'T HAPPEN and the power stays on).

This results in a short circuit across the magazine armature bringing the magazine to a quick stop in addition to turning off the selection indicator lites. This completes the mechanism cycle.



Regardless, I have to resolve this problem and get back to checking to see if the bulb (the bulb itself is good) flashes when the carriage stops.

[jukenorman]

Hi tcw,
The light that you see flashing is the current limiting lamp in the selection write-in circuit and has no part to play in magazine motor operation.

You say that when the magazine motor has "homed" (and we can see it is in the home position in the photo), that the play control relay does not de-energise. This would only happen if the wobble plate switch was still made (selection registered). If you put the scan switch to off, the play control relay should de-energise.

When you operate the scan switch, the play control relay should operate (it looks like it does because the turntable runs) and the magazine motor should run - provided the cam switches are in the correct position, and we must assume they are, because the magazine motor has just found its way to the home position. I would say that from the information that you have provided that the magazine motor is faulty and requires servicing.

We can return to the selection issue when you have got this issue resolved - one fault at a time!

Norman.

[TCW]

I put some fresh eyes on it this morning and its the magazine motor. I tried turning it by the knob and nothing doing. I then unplugged it and the breaker doesn't trip now and the turn table just spins. I'll loosen it up and see if its bound mechanically or if its a winding issue.

[TCW]

The gears on the magazine motor where meshing to tightly. I loosened it and got it running and slowly tightened it down. That's done it. These never seem to be one layer deep though. Now its only able to read B sides. So now I will be taking a look at what should be coming through the Read Out Carriage Contact Assembly for the A side when it gets closed from a selector key.