Hammond Model A, Manual, Page: 294 / 298

5-81. The switches for the start and run motors are both mounted on the same metal
plate; the following replacement instructions are equally applicable to each:
a. Remove the black bakelite switch handle by unscrewing it in a counter
clockwise direction.
b. Remove the round knurled nut which holds the switch to the metal plate.
c. Remove the four oval-head screws which hold the switch plate to the music
rack.
d. Remove the rear panel of the console.
e. Unsolder the leads (from the defective switch) at the power terminal panel
on the generator. One lead (black) is wired to the start switch. Four leads, 1
yellow,1 black, 1 blue, and 1 brown, are wired to the run switch. (See Console
schematic). Unscrew or unsolder jumper wire between switches.
f. Remove the tape which secures the wires together. Unbraid the wires
connected to the defective switch up to the manual chassis so that the switch can be
removed.
g. Pull out the switch. Note the position of the switch with respect to the
color of the wires so that the replacement switch will be installed in the correct
position.
h. Install the new switch in the proper position. Braid and tape the wires
carefully so that they will not interfere with the operation of the generator run
motor.
i. Solder the leads of the replacement switch to the power terminal panel.
j. Operate the switch to determine that it has been installed properly.
k. Replace the rear panel.
5-82. START MOTOR (See figure 5-3 on p.17 of this section).
5-83. Replacement of the start motor will be accomplished as follows:
a. To make the start motor accessible, follow the procedure for removing the
main tone generator. (Reference paragraph 5-63.)
b. Remove start motor capillary threads from oiling trough.
c. Disconnect the leads to the start motor at the power terminal panel on the
generator.
d. Using a socket wrench, remove the two start motor mounting screws.
e. Secure a replacement start motor in position by reversing the procedures
above.
5-84. RUN MOTOR AND VIBRATO SCANNER ASSEMBLY.
5-85. Replacement of run motor and vibrato scanner assembly will be accomplished as
follows:
a. Remove the rear panel.
b. At the power terminal panel on the generator, unsolder the red and black
wires which lead to the run motor that is to be replaced. (See console wiring
diagram.)
c. Unsolder 7 scanner wires from terminals on back of stop base and 2 scanner
wires from line box.
d. Remove shielded lead attached to SCAN at preamplifier.
e. The running motor is secured by four machine screws to the generator frame.
Remove the nuts and lock washers, and then disengage the flywheel coupling springs.
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