TM 9-4120-404-14
(2) Potentiometer.
(a) Using multimeter set on scale for measuring 5000 ohms, place probes on terminals 1 and 2.
(b) Turn potentiometer shaft fully clockwise.
(c) Check that multimeter indicate 5000 50 ohms.
(d) Slowly turn shaft counterclockwise while watching dial on multimeter.
Indicated ohms resistance
should smoothly and gradually decrease.
(e) Continue to turn shaft until the fully counter clockwise position is reached. Multimeter should now
indicate between 5 and 50 ohms.
(f) Replace potentiometer if it fails any of the above tests.
(3) Light Emitting Diodes.
(a) Apply a 5-6 volts DC across leads of each light emitting diode.
(b) If any light emitting diode does not shine, replace it.
d. Repair.
Repair of control panel assembly is limited to replacement of defective parts found during testing.
e. Assembly.
(1) Attach P6 connector (17) to control box (18) and install two screws (16), two flat washers (15), and two nuts
(14).
(2) Install four light emitting diodes (13) into control panel (10).
(3) Install potentiometer (6) and mode selector switch (4) into control panel (10).
(4) Refer to tags installed during removal and reconnect all wires to mode selector switch (4), potentiometer
(6), and four light emitting diodes (13), and then remove tags.
(5) Install screw (2), star washer (12), and nut (11) int o control panel (10).
(6) Install control panel (10), four lock washers (9), four flat washers (8), and four screws (7).
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