Hammond tone wheel organs - missing tone diagnosis

[Dillon Holeman]

Hey guys,

I'm new to this forum and Hammond service, but I have five of them so I figure I'd better learn to work on them! I've got a BV with a missing tone and I did the test with a jumper from the #6 busbar to the TG terminal strip per the Hammond console service manual. I was just curious: Why the #6 busbar? Why not any of the other bars?

Also the manual says "6th busbar from the bottom" but the busbars are labeled 0 through 8. Technically the 6th from the bottom would be the one labeled "5". I used the one labeled "6" and it seemed to work fine. Which is the correct busbar to use, and what is the significance of using that one over any of the others?

[Tim_at_Jonas]

Check for a bad solder joint on the back of the TWG (cause it's easy). If no joy, you'll need to tip the manuals up (search for info on how to do this), remove the green TWG cover, and look for bad joints on the filters. (I think there's a thread on this elsewhere in this section of the forum.)

[geoelectro]

you can use any busbar on the preset panel. if you use "0" you won't hear anything. If you use "8" it will be really loud.

Geo

[Dillon Holeman]

Thanks Geo. That makes sense. Never tried changing the presets so I never really thought about it, but I think I get how it works now. Each busbar is electrically equivalent to one of the possible positions of a drawbar, right? Cool.