Seeburg V-200 number & letter selection makes sound increase

[jimfusco]

Hi everyone- been a while since I've posted.  I wrote about this a long time ago and have been trying to understand it for years.  But now I think I'm onto something and wanted to understand why this might be happening (and how to fix it).

So, my V200 works great but from time to time the sound basically cuts out almost all the way (sometimes it's 50% softer, sometimes 90-99% softer) and then by the next song it comes back full volume again.  I've turned off the noise reduction circuit and that doesn't affect anything.  

But what does seem to bring the volume back is if we put another coin in and then select a song.  Something about pressing one of the letter or number (mostly number, I'd say) buttons makes the volume instantly kick back to full again.  But why would the button selectors have any bearing over the volume (or maybe the output to the amp)?  And if that's the case, any ideas on how I can rectify that?  I'm thankful I've found that putting a coin in (you have to do that- just pressing the letter and number buttons without a coin in doesn't do anything to the sound) brings the sound back, but obviously that shouldn't be happening.  Any insight would be appreciated!

~Jim

[jukenorman]

It's very hard to diagnose this type of fault. Probably some interference being generated by the operation of the pushbuttons is interacting with some dodgy component in the amplifier. I myself had something very similar this past week which turned out to be a dodgy tube (or thermionic valve as we would say), just lightly jiggling it recreated the problem. You could start with that but I have to say that I would be amazed if two of could be that lucky in the same week but you never know!

Norman.

[jimfusco]

Thanks so much, Norman- I appreciate the reply. So you think that it's more of a physical thing (jostling a tube/thermionic valve) rather than something like, "The wire that sends the signal from the pushbuttons to the selector is cutting a signal to the amp". It's so hard to describe over text. It almost seems like when I press the selector buttons the sound is "released" because of how quickly it comes back to full volume.

[jukenorman]

There is no electrical connection between the keyboard and the amplifier so what you are getting is some sort of interference. It's not uncommon to find jukeboxes popping when parts of the mechanism operates resulting in contacts having to be suppressed by a capacitor for example. But your's is a stage worse in that the interference is affecting the amplifier operation. I think starting with the tubes is an easy first option, try lightly jiggling the tube in its socket or tapping with a pencil to see if the problem area can be identified. It does help if you have some spare tubes for substitutions. Best of luck is all I can add!

Norman.

[dberman51]

Has the amplifier been re-capped? I have a radio that developed a similar problem many years ago. The audio would fade away, but creating a transient (turning a large appliance or fluorescent light on or off) anywhere in the house would bring it back instantly, for a while. A failing capacitor was the cause.

-David