The bad news is, if you have more than one bad divider for a given note, you can't test the lower ones until you get the ones above it working.

Each divider circuit is a small collection of components on the generator board.

You'll see a repetitive formation of components starting near the oscillator circuit. In my experience, most divider problems are caused by a bad transistor, but bad capacitors or just bad solder joints can be the culprit.

It could even be a bad resistor, but that would be rare. As noted above, a bad key contact in the top octave displays the same symptoms as a bad oscillator circuit.

To test the oscillators, turn on the highest even-numbered footage voice, usually 4' or 2'. If any of the notes fails to play, then you probably have a bad oscillator.

To confirm this, play that same bad note in lower octaves.

Divider problems cascade - once you have a bad one, none of the notes below will play correctly.

The good news is, once you fix that divider, there's a good chance the lower notes will suddenly come to life.

If the failing note is the lowest on the keybard, with the 16' voice on, then it could be either - there's no way to tell without checking the contact out and/or testing with a signal tracer (see below) What about the bass octave(s)?

We've been ignoring the bass octave(s) til now, because they can muddy the waters of diagnosis.

It would be extremely unlikely for a tuning coil to have a broken connection inside - it's most always the connection from the coil to the circuit board that's gone bad. There may be as many as 5 or 6 dividers for each note.