Rockola Tempo II 1485 - Restoration

geschrieben von - posted by Dvd739 
Rockola Tempo II 1485 - Restoration
16.06.20 12:49
Hi everyone.

I own a Rockola Tempo II mod. 1485 that I am restoring. I reassembled all the electromechanical parts and, trying to make it work, I noticed the following problems:

1) by connecting the power plug, the carousel motor always remains powered, even if the Control Box selector is in the OFF position;
2) the carousel turns backwards, clockwise. Reading the manual, it should always turn counterclockwise;
3) the carousel engine is struggling to start, it needs a "push" to overcome the inertia of the carousel. Could it be a problem with brushes or some condenser?

I thank you all in advance for your ideas and I will keep you updated on the progress. Also because there will certainly be other problems continuing the work!
Re: Rockola Tempo II 1485 - Restoration
16.06.20 19:02
Hello Dvd739

The magazine motor has a field coil. If this does not work (not connected or defective), the motor can run too fast and nobody knows in which direction it is turming. It can also cause startup problems. You should therefore check whether there is voltage on the field coil and whether the field coil has continuity.

Perhaps the Scan Switch Assembly is not reset correctly when the magazine rotates in the wrong direction. That could be the reason why the magazine keeps turning. It should make a maximum of four turns after a selection.

Best regards - charly49
Re: Rockola Tempo II 1485 - Restoration
23.06.20 21:39
Hi Charly49,

I didn't check the voltage, yet. I'm not an electrician, so I don't know how to check with tester.
Regarding the Scan Switch Assembly, I reset manually it (all the teeth of the Scanning Ratchet after 4 turns of carousel in the proper direction) but when I connected the plug, the motor is with power.

I have a doubt about the "control box". With the tester, I observed that in the red socket of the control box in which the red plug of the motor is inserted, the red-blue and orange-white wires always form a closed circuit in all OFF and SCAN and OPER positions. I don't know if this is normal. I attach 3 pictures of connected wires of selector in 3 positions of the Control Box knob to understand which contacts are connected. Counterclockwise, the wires are: white-brown, empty, black (earth), yellow-green, orange-red, empty, empty, green.

A big thank you!


Re: Rockola Tempo II 1485 - Restoration
26.06.20 12:38
Hello Dvd739

It is important that you can measure the voltage values (and also resistance values). You should find someone to explain how to use the multimeter. Otherwise it is not possible to help you.

Best regards - charly49
Re: Rockola Tempo II 1485 - Restoration
02.07.20 16:46
Hi Charly49,

I checked the voltages with tester in the pins of the red plug of Control Box. See attached file.
I don't understand where the resistances have to be measured. I don't know if the file attached can help to understand if the connections are right or wrong.


Re: Rockola Tempo II 1485 - Restoration
05.07.20 13:41
Hello Dvd739

In the OFF position of the service switch, absolutely no voltage should be measured in the control box. According to your table, a voltage can still be measured. The reason for this is likely to be found in the power supply. There is the PLAY CONTROL RELAY. In the OFF position of the service switch it must have dropped out, the contacts on it must be open. A capacitor can be connected in parallel with the contact that switches on the voltage for the mechanism. This capacitor can be short-circuited. If that's the case, you can easily cut it out. It is not important for the function, it only protects the contacts. A new one should therefore be installed at some point.

The resistance values are measured with the multimeter in the ohm range. If the multimeter does not have an autorange function, use the lowest ohmic range (usually 200 ohms). On the motor - plug four wires are connected. Two wires are for the field coil. A resistance value of 50 - 100 ohms should be measured. The other two wires are for the armature. The resistance value should be between 5 and 10 ohms.

When the motor is running, a wire for both the field coil and armature should be grounded. This probably applies to the armature connection, because it is directly connected to ground. If it does not apply to the field coil connection, it is probably due to Camshaft Switch # 2, because this must switch the connection to ground. According to your table, this should be your problem.

Best regards - charly49
Re: Rockola Tempo II 1485 - Restoration
05.07.20 20:38
Dear Charly49,
very interesting what you wrote!
When you mention the capacitor connected in parallel to Play Control Relay, do you mean the resistor (item 3 in attached draw)?


Re: Rockola Tempo II 1485 - Restoration
06.07.20 11:53
Hello Dvd739

Obviously, this model does not have this capacitor, so it cannot be short-circuited. The fault must therefore lie in the relay contacts themselves.

As already mentioned, the relay must have dropped out when the service switch is set to OFF. If the relay has dropped out, the contacts must not touch each other. Once you've checked that, we can see further.

Best regards - charly49
Re: Rockola Tempo II 1485 - Restoration
08.07.20 15:51
Hi Charly49,

another step forward thanks to you!!!
One of the relay contacts had the fixed slat too close to the mobile slat and the circuit was always closed. I opened a little bit this slat and now the power is at motor only in SCAN and OPER positions (the last one when the microswitch of Scanning Switch is in Play position). So, that's seems to be solved.
Now I want to go forward.

- magazine motor runs clockwise. Since the Power Unit has been restored, could it be that 2 wires have been reversed?
- after inserting coin, I hear a "tic" in Accumulator but the Solenoid Plunger of the Scanning Switch doesn't move to the Microswitch Lever so that the microswitch doesn't close the circuit
- if I move manually the Solenoid Plunger, magazine motor and turntable motor start to run but, after doing the selection, the Selector Lever doesn't move to external for reporting the selection to the Carriage. If I move manually the Selector Lever, all the rest of the cycles proceed correctly till the end.

I know I'm very incompetent ... :-I

But, thanks once again!
Re: Rockola Tempo II 1485 - Restoration
09.07.20 10:25
Hello Dvd739

I am glad that you could fix a bug.

It is unlikely that in the restoration of the power supply wires are reversed. Otherwise the gripper motor would run in the wrong direction.

I will try to describe the selection process because you may have misunderstood something.

When you insert a coin, you only hear a soft click in the credit unit. This is the add coil that counts a corresponding number of credits on the credit accumulator. This should make the SELECT light come on. Otherwise nothing happens preliminary.

If you press a selection button, the reset coil in the credit unit should pull in briefly. The reset coil resets the accumulator one step and actuates three contacts. One completes the circuit to the selection coils. The second completes the circuit to the commoning relays. The third activates the Scan Control Solenoid, which starts the scanning process.

Something else happens internally that cannot be seen from the outside. There is an electrolytic capacitor with two sections in the credit unit. The first section is always loaded. If the accumulator is no longer in the zero position (after inserting a coin), the second section is also loaded. The current goes through a series connection of all selection buttons. So no key must be pressed at this time.

The circuit to the commoning relays is prepared by the group buttons (lettered program switch buttons). The selection buttons prepare the circuit for the selector coils. Pressing a selection button also creates the circuit from the loaded second section of the electrolytic capacitor to the reset coil. The electrolytic capacitor therefore discharges via the reset coil, which means that it is pulled on for a short time and triggers the further processes.

I hope this will help you.

Best regards - charly49
Re: Rockola Tempo II 1485 - Restoration
01.08.20 14:17
Dear Charly49,
I'm back again after my summer holidays ... and it's time to go ahead with my Rockola.
I followed your instructions and I saw that, after inserting coin, I hear the soft click in the credit unit but the SELECT light doesn't come on and nothing else happens. What could it be: the electrolytic capacitor of credit unit? Which checks can I do for understanding the causes?

Thaaaanks!
Davide
Re: Rockola Tempo II 1485 - Restoration
02.08.20 09:34
Hello Davide

There are two contacts that engage between the credit accumulator gears. The contacts are normally closed and only open as soon as the Credtit Accumulator reaches the zero position. One of the contacts is for the credit lamp, the second one allows the selection. It establishes a connection from the first section of the electrolytic capacitor via a small resistor (47 ohms) and a series connection of all 40 selection buttons to the second section. The second section of the electrolytic capacitor is charged to the same voltage (approx. 30 VDC) as the first section. None of the buttons may be pressed at this time.

When a selection button is pressed, the electrolytic capacitor is discharged via the reset coil, which actuates it and triggers the further processes.

Best regards - charly49
Re: Rockola Tempo II 1485 - Restoration
02.08.20 17:17
Hi Charly49,
other trials made today.

1) The Credit Accumulator, when I switch on the power, has to be in the zero position? I suppose yes, and when I insert a coin one or more teeth of the gears are scaled and the two contacts close, right?

2) After one or more teeth are scaled, select light should come on but it doesn't happen. Why?

I don't understand why after the click nothing happens and if I can solve this problem replacing the can capacitor.

During all the trials for testing the accumulator and the lamp, the front door must be connected, right?
Many thanks!
Re: Rockola Tempo II 1485 - Restoration
04.08.20 11:46
Hello Davide

The number of credits is mechanically stored. If there were credits before switching off, then they are also available after switching on.

After inserting a coin, the credit accumulator is no longer in the zero position and the two contacts close (not just look, but measure). One is for the lamp, the second prepares the selection process. Then the credit lamp should light up. If it doesn't, maybe the lamp is burned out or has poor contact in the socket. For the credit lamp and for the arrow lites, the power supply delivers 6 VAC. It is possible that this is missing. A wire could also be broken somewhere. I hope you are familiar with using a multimeter.

Apart from the lighting up of the credit lamp, there is no visible reaction after inserting a coin. But something happens inside. The second section of the electrolytic capacitor is loaded. The current goes from the first section (which is always charged to about 30 VDC) via the contact and a 47 ohm resistor and a series connection through all 40 selection buttons to the second section. If the second section is not loaded, the keyboard is usually the cause.

When a selection button is pressed, charging is interrupted and the second section of the electrolytic capacitor discharges via the reset coil (the large coil next to the accumulator). This attracts and resets the accumulator one step. At the same time, the contacts close and complete the circuits to the selection coils.

The processes are described in detail in the service manual. Using the manual, you can track the circuits with the multimeter. If you don't have a manual, it is available here in the shop. [www.jukebox-world.de]

If you don't have enough electronics knowledge, you should find someone near you who can help you.

Best regards - charly49
Re: Rockola Tempo II 1485 - Restoration
08.08.20 09:25
Dear Charly49,
I have the full manual of Rockola 1485 but your recommendations are absolutely helpful for me because you drive me in investigation of faults.

I checked the following:
- select lamps, one of 3 was burned, now it's ok. The other 2 are new but don't light but I will check further, I would say it's a minor gap;
- I measured the resistance of 47 ohm resistor: it's 54 ohm, too much?
- the keyboard seems to be ok, I checked the circuit at "pins" of wires grey-black and purple-white that enter into the accumulator assembly and there is continuity;
- the electrolytic capacitor is charged to 15 VDC (not 30).

All the steps seem to be ok till when I press a selection button (1-40): the reset coil armature moves (that means the keyboard is ok, too) but is not able to close the contacts (all the sections middle, right and left) and to move the reset pawl enough to go back of one tooth of the master racket. If I do it manually, contacts close and the reset pawl does its job. It seems that the coil reset has not enough force, could it be due to the 15 VDC charge of electrolytic capacitor instead of 30 VDC?

Thanks! Thanks! Thanks!

Have a nice week-end!
Re: Rockola Tempo II 1485 - Restoration
10.08.20 06:04
Hello Davide

Which section of the electrolytic capacitor is only charged to 15 volts? If it is the first section (connected to the selenium rectifier), the electrolytic capacitor is probably defective. It is also possible, but not very likely, that the rectifier is defective.

If the first section of the electrolytic capacitor is charged to around 30 volts, but the second section is only charged to 15 volts, then it is most likely due to the keyboard. If no key is pressed, the series connection of all 40 keys may have a resistance of less than 1 ohm. It is also possible that the capacitor is defective. You can easily test whether it is the keyboard or the capacitor. To do this, briefly connect the second section of the electrolytic capacitor to the first and then measure the voltage on the second section. If the tension is just as high as on the first section, then it is definitely the keyboard. If the voltage drops again after a few seconds, the electrolytic capacitor has a too low insulation resistance and must be replaced.

Best regards - charly49
Re: Rockola Tempo II 1485 - Restoration
10.08.20 16:23
Hi Charly49,
I checked everything following your instructions:
- the first section of capacitor is charged with 15 VDC;
- if I connect the second section, this is charged with 15VDC, too;
- the resistance of the keyboard is zero.

So, I suppose the capacitor can't charge its first section at 30VDC but only at 15 VDC and the keyboard does its job charging the second section at 15 VDC, too. And this tension is not enough to attract fully the reset coil and let it do its job. Correct?

Now, how can I identify it the fault is in the capacitor or in the rectifier?

Thanks again!
Re: Rockola Tempo II 1485 - Restoration
11.08.20 10:04
Hello Davide

I think your statements are correct.

If you have a capacitance meter, you can use it to measure the capacitance value directly. If not, all you can do is try. Maybe you have an electrolytic capacitor in your handicraft box. The value is not important. It can have 10 ... 1000 MFD. It is important that it has an operating voltage of more than 30 volts. Then you unsolder the wire that goes to the first section of the original electrolytic capacitor and solder the wire to the positive connection of the new electrolytic capacitor. The negative connection is soldered to the negative connection of the original electrolytic capacitor. If you can now measure the required 30 VDC on the new electrolytic capacitor, then the electrolytic capacitor is defective. If the second section of the capacitor is still working, a selection should be possible. If you can't find a capacitor to try, you can buy one for a few cents in an electronics store. (e.g. 220 MFD 50 volts would fit).

If the voltage with the replacement capacitor is still too low, then the rectifier is the cause. These selenium rectifiers are no longer commercially available, but can be replaced by a silicon diode. E.g. a 1N4002 ... 1N4007 would be suitable, but also any other with at least 50 volts / at least 1 ampere. Diodes are polarized components. They have a colored ring on one side. This is the cathode connection that must be connected to the capacitor. The old rectifier must be unsoldered at least one pole, the second connection can be used as a soldering post.
Re: Rockola Tempo II 1485 - Restoration
10.09.20 21:10
Hi Charly49,
after long investigation I identified the problem in the transformer. 2 years ago a workshop rebuilt it but made a wrong exit: 12,5 VAC instead of 25 VAC, so that the rectifier can't give 30 VDC to capacitor but only half (15 VDC).
After modifying the transformer as the original one, the reset coil works properly. Thanks again for your inputs, you are driving me in the right way!
Now, the magazine motor again runs clockwise instead of counterclockwise. I checked all the external wires with the wiring diagram and it's okay. Maybe, the motor has been refurbished in the past and wires have been inverted. My idea is to invert the 2 wires of the rotor (the 2 wires of the coil remain as they are) and I suppose the rotation will be opposite, do you agree?
I put new brushes but if the motor will be too weak at starting for moving the magazine, I will send the motor to workshop for full refurbishing.
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