Continental AMI Juke Box Fault Finding

[Ron Rich]

Rob,
I would definitely say to replace those ("bumble bee") caps !
Ron Rich

[rob1948]

Hi Norman/Ron,
Just for information, I have been onto U Tube and found, 'How to read Bumblebee Capacitor Values' and from that the two top capacitors are 0.1uF 600V each, which is close to your guess of the two forming the 0.25uF in your post. Thanks Rob

[jukenorman]

Hi Rob,
You should be able to get a single 0.22uF as a replacement. If the capacitors were in an audio application, I would say definitely change them but suppression on relay contacts? Changing them will not cure your problem though, so don't build up your hopes!

Norman.

[rob1948]

Thanks Norman. I have removed the Search Unit from the JB which is going to allow for easier access and inspection of relays and tracing of wires etc. Will keep you and Ron posted on any progress or 'break through'!! Rob

[rob1948]

Morning Ron/Norman,
With the search unit out I have been able to examine the Pulse Relay and Sprag Relay contacts closely and of course there is a set of contacts in each relay that look 'suspect' and rather worn down, less than 50% of original size and as per your FAQ 'Contact Care' should be replaced. Chances are the contacts are unable to carrying the necessary current? I have contacted Steve at Victory Glass to see whether he has new or second-hand relays available, although doubt it ?. Need to source new contacts and then I think I must replace all the relay contacts while about it. Just an update. Thanks Rob

[Ron Rich]

Hi Rob,
Can you describe the blades on that relay body-- are they the copper colored blades, with the slight curve in them ? Ron Rich

[rob1948]

Hi Ron,
Sorry wasted a post again! Yes the blades are a copper/bronze colour and the fixed blades on both the PCR and Sprag Relay are curved for the contacts to make contact with the straight moving blades. There is also 'blueish' residue on some of the blades around the contact ? Replacing the PCR with a new 'plug in relay', is this not an option ? Thanks Rob

[Ron Rich]

Hi Rob,
That's what I expected-- The bluish color is a result of heat-that blade/contact is NOT making well, and IMHO it's the reason for your problems. I am not a fan of that type relay-- In most cases, a proper ("ice cube") plug in relay, can replace it. I would use a relay socket for sure, which can be supported by "Velcro" attached to the relay itself and a suitable space on the chassis.
As for "wasted posts"-- It's easy to either 'edit' or delete them- To edit, just click the "edit" button on the upper right of the post To deleat it, click on the "gear icon", that's further to the right of the edit button. I'll delete the "wasted one"--LOL Ron Rich

[rob1948]

Thanks Ron for your feedback. I am going to go ahead and source a plug in relay. And also for the system lesson, no more wasted posts !! Rob

[rob1948]

Hi Ron/Norman,
EUREKA !! Found the problem !! 6 circuit male plug assembly at the back of the Search Unit, found a broken connector pin in the plug assembly on the blue and white lead which is the feed to the scan magnets and selection solenoid. Replaced the broken pin and all is good !!! What a long journey !! Thanks again for you guys input and assistance !! All that remains now is to find and fix a faulty transfer motor stopping switch.(record is placed on the turn table, tone arm moves across onto the record but immediately retracts and the record is placed back in the magazine) Norman, because the selection pin is being reset, you previously mentioned that this could be as a result of a faulty stopping switch? Further progress - the valve stereo amplifier has been fixed which I must now just collect and install, then we are done !! Thanks Rob PS - No doubt that the plug assembly pin was the problem, I also replaced the PCR with the one out of my spare Search Unit which had 'better looking' contact points.

[jukenorman]

Hi Rob,
You are getting there, for sure! I tried to find what I said previously about the stopping switch just to check the context but couldn't find it!

What happens is when CS6 operates, a circuit is made (through the operated stopping switch) to the reset solenoid resetting the selection pin. The reset pin then allows the stopping switch to change over which in turn drops out the transfer relay to stop the transfer motor. So yes the stopping switch could be the problem.

Does this happen with both A and B side selections? Alternatively you may need to look at the stopping switch adjustment procedure on page RCS-25. You might also be to see what the problem is by stopping the transfer (switch off) at the point the pin is reset.

Norman.

[rob1948]

Morning Norman, This is your previous post - 'With regard to the transfer motor not stopping when a record is placed on the turntable - is the selection pin being reset? If the pin is not being reset, this is down to cam switch 6 - is it operating? If the selection pin is being reset, that would point to a faulty stopping switch (assuming the reject switches themselves are not the problem!)'Yes the selection pin is being reset and it does happen with both A and B side selections. Where are the reject switches Thanks Rob

[jukenorman]

Hi Rob,
The reject switches - one is the record reject switch at the base of the tone arm and the other is a the manual pushbutton adjacent to the volume control. If either of these is shorted or in the "made" position, then the record will reject immediately. The manual pushbutton connects via the amplifier so you can rule it out if you have still to collect the amp.!

I would concentrate on the reject switch first (cut off switch as AMi refers to it). I'm glad you reminded me about it, it's often so easy to overlook the obvious!

Norman.

[Ron Rich]

Hi All,
Thinking "outside the box", has the volume control area been re-attached to the amp, correctly-- no "hair wire shorts" ? Ron Rich

[rob1948]

Hi Ron, The valve amplifier has not yet been re installed, but I will take care when I install it .Thanks