Hammond A-105 missing note issue.....

[Grasshopper]

Hello again all you experts,

Got a freshie for you!

I just obtained a Hammond A-105 that sat unused for 30ish years.
She was dry as a bone with nothing moving but she is super clean. I gave her a 50/50 lighter fluid/Hammond oil mix and she fired right up. (oiled after)
After swapping out a Reverb amp that would not power up, a few noisy bearings, and a gummed up run motor, she now has a full 23 sec rundown time.

This is when I found my current problem.
Upon testing each key, with one drawbar out at a time, I found I am missing my first D on the upper manual with the 7th drawbar (from the left) pulled out.
I do not hear the D on any of the black presets or the 2 drawbars presets.

Where should I look first for this missing note?

As always, thank you in advance for all your help and extended knowledge!

The Grasshopper

[David Anderson]

Pull out the 8' drawbar only on the A# preset on both manuals. All other drawbars should be pushed in. The lowest white key is now #13. Go up the manual counting keys until you find your missing tone. Try this on both manuals.

Once you have the number of the tone, find it on the TG terminal strip. Put a clip lead on the terminal and touch the clip lead to one of the preset panel busbars. If the tone is there, you have a problem in the wiring harness or something like a bad solder joint at that terminal. It's not uncommon to have wires break at the upper manual terminal strip.

This usually fixes it unless you have a problem with a manual contact, but that is much more rare.

[Grasshopper]

Thanks David!
I tried what you suggested and I did not find a missing tone with the 8' drawbar only with A# preset on either manual.
Manual contact is the problem?

Also, the 8' is the 3rd drawbar from the left correct? Fundamental?

[David Anderson]

I should have added that the 8' drawbar does not access all the tones. Pull out the last drawbar (1'), and start at the same tone as the highest tone on the 8' drawbar, the third C key. This will be tone 73. Go up an octave and a half. Tone 91 is F#.

[Grasshopper]

I got the same results. No missing tones.
I am starting to get nervous...........

[David Anderson]

Is this a manual with foam in it? If all the tones are present at both manuals, but a tone is still missing under a certain key, that starts to point to a problem inside the manual.

You might play the length of both manuals one drawbar at a time to see if you have missing tones anywhere else.

If you're lucky, you might simply have a dirty contact.

[Grasshopper]

It is a foam model as it is a 65' that was sold in 67'.
I have played all the drawbars one at a time, one note at a time and it is the only tone that is missing.

[David Anderson]

You can try playing that note repeatedly or shifting the busbars to see if it returns. If not . . . I suppose it could be a sign that you have decaying foam in your manuals that is starting to eat through the resistance wires. Obviously I can't see into the manuals, but that is one possibility.

[Grasshopper]

could it be anything on the filter tray on top of the tone gen?
I remove the felt cover to clean up and put it back on.
Could I possibly of screwed up a wire?

[David Anderson]

I get that you're trying to negotiate with reality here, but if a tone is showing up in one place in the manual, but not another, the problem is inside the manual. End of story. Each tone enters the manual wiring on one terminal at the back of the manual. From there, it branches out to all the individual contacts where it's supposed to appear.

[Grasshopper]

ok.....just asking.

Thank you for your help.

[David Anderson]

I'd love to give better news, but if you are missing one tone due to deteriorating foam, that's when you need to act to stop it from getting worse. Again, I can't know that that's what's happening, but it's a possibility.

[nonreverb]

An unfortunate problem with post '63 console Hammonds. I recently did two of mine with foam. Both had missing notes. :-(

[Grasshopper]

An unfortunate problem with post '63 console Hammonds. I recently did two of mine with foam. Both had missing notes. :-(

Did your notes come back after the foam removal?
I now also have 2 that need de-foamed.