How To Clean Key Contacts

Three steps are mentioned in the ServiceManual for progressively bad cases.

1. Play the organ

First, try striking the offending key 15 to 20 times in a rapid staccato manner to dislodge the dust particles and to clear the contacts.

(Realistically, if this step doesn't fix the problem to your liking, it may be time for a BusbarLubeJob.)

2. Busbar shifters

If this procedure does not dislodge the dust particles, adjust the busbar shifters. The busbar shifter for the upper manual is a slotted shaft about 1/2" in diameter, protruding about 1/4" from the rear surface of the upper manual assembly. It is located behind the mixing transformer. The lower manual adjuster is located in the corresponding location on the lower manual. The shifter for the pedal assembly is located at the low end of the pedals.

Turn the proper busbar shifter about two turns in either direction. This operation permits the key contacts to strike a new position on the busbar and should free all contacts of accumulated dust particles.

Warning: Before shifting the busbars make sure to cancel all presets. (See below.)

Note: Some spinets (notably the M-100 series) don't have the screw mechanism for shifting the busbars. Instead, there is a hole on the underside of the left-hand (from the front of the organ) wooden endblock of each manual. Inside the hole will see a little metal tongue with a hole punched in it. You grab or hook the tongue with a needle-nosed pliers, or a poker of some sort, and pull it in or out to shift the busbars.

3. Drastic Measures

If, in extremely stubborn cases, the procedure above does not dislodge the dust particles, use a board to depress one octave of notes (or the offending key) and then adjust the busbar shifters holding the key(s) down.

A warning about this procedure was issued in a Keyboard article, Nov. 1991:

"... 'This is extremely dangerous,'... 'and should never be done by anyone except a technician who knows that the busbars are in absolutely perfect condition. If the keys are worn enough to have notches in their contacts, running the busbar back and forth against depressed keys can saw those little contact wires in half.'..."

Also, the PresetKeys are implemented similarly to regular keys, with the same type of key contacts and so forth. So if you choose to adjust the busbar shifter, as (2) and (3), be sure that no PresetKeys are latched down, else the same damage could occur as in number (3) above.

 BusbarLubeJob
 HammondMaintainanceAndTroubleshooting