Shorts In The Manual

A common problem is caused by the growth of MetallicFuzz within the manuals. This can be one of the CausesOfCrossTalk, CausesOfHum, and (when the short affects the ninth bus-bar of the upper manual) can cause the percussion to fail.

Checking for Shorts in the Manual

1. Turn off the organ.
2. Detach one bundle (one preset's worth) of wires from the preset panel.
3. Select the preset corresponding to the bundle you've got disconnected.
4. With a good (modern, low-voltage) ohm-meter measure the resistance between each of the preset wires and chassis ground.

Resistance should be roughly infinite when no playing keys are depressed --- and not much (a few tens of ohms) when a key is depressed.

If you have dendrite problems you'll probably see a few hundred ohms (with no playing keys depressed.)

Possible Fixes

If you believe in flashing (which could conceivably cause all kinds of damage, particularly if you don't understand exactly the path taken by the flashing current...):

You might find some relief by flashing (e.g. with a nine volt battery) between the preset wire and the manual chassis ground. (Disconnect the ohm-meter first! Flash across the same two points the ohm-meter was connected to. Reconnect the ohm-meter and see if anything has changed. Keep flashing until the ohm-meter shows an open circuit.)

In my experience, flashing tends to be a temporary solution to this problem... The problem tends to come back --- often after the organ is moved.

A bus cleaning/lube may help, too...

TopicTroubleshooting