Hammond L-100 - "Ghost" Overtones related to Drawbars

[Jayz]

Both the 5th and 6th harmonic drawbars on the upper manual on my L-100 are producing ghost notes. They disappear when the drawbars are pushed completely in. Can anyone suggest how I might determine the cause and how to fix?
Thanks.

[KC9UDX]

You can determine which notes these are by pressing each key. The two keys that don't sound different when pressed (with those two drawbars out all the way) likely have dirty contacts. You could then try rapidly pressing then repeatedly and see if it goes away.

[Jayz]

Thanks. Each key that I press sounds different than the "ghost" tones are producing alone. I tried the "rapidly" pressing but without success.

[KC9UDX]

That's interesting. So with just one of the two offending drawbars pulled out all the way, each and every key sounds different? Are there any that have the same tone but just different volume, or do they all have a different tone (than the "ghost" tone)?

Still I expect a simple short circuit, but perhaps there's more to it.