Replacement of rotary or toggle switch

TM 55-4920-430-13

(7) Install the meter lens cover (para 3-8).

(8) Install the panel in the case (para 4-39).

(9) Perform AC/DC VOLTMETER adjustment (para 4-37).

(10) Test the AC/DC VOLTMETER (para 4-45).

b. Replacement of rotary or toggle switch. (See fig. 5-4.)

(1) Remove the panel from the case (para 4-29).

(2) Tag the wires, then unsolder or disconnect by removing the screws.

( 3 ) For a rotary switch, remove the knob by removing two screws from the knob.

(4) Remove the nut and washer that secure the switch to the panel.

(5) Note its orientation and remove the switch from the panel.

( 6 ) Position the replacement switch in the panel.

(7) Secure the switch to the panel with the nut and washer.

(8) Solder the wires, or connect them by installing screws, Use solder (item 5, table 4-1). Remove

the tags.

(9) For rotary switches, position the knob and tighten two screws.

(10) Install the panel in the case (para 4-39).

(11) Perform final test (para 4-40).

c. Repair or replacement of receptacles and terminal boards. Refer to TM 55-1500-323-25. See the

wiring diagram in FO-55.

d. Replacement of RESPONSE TEST TIME DELAY - SEC switch. (See fig. 5-4.)

( 1 ) Remove the panel from the case.

(2) Tag and unsolder the wires from the terminals.

(3) Remove the four screws and washers that secure the switch to the panel.

(4) Remove the switch.

(5) Position the replacement switch in the panel.

(6) Secure the switch with four screws and washers.

(7) Solder the wires to the terminals. Use solder (item 5, table 4-1). Remove tags.

(8) Install the panel in the case (para 4-39).

(9) Perform response test (para 4-64).

e. Replacement of pitch ATT-HSI HDG potentiometer R19. (See fig. 5-4. )

( 1 ) Remove the panel from the case (para 4-29).

(2) Tag and unsolder the wires from the potentiometer.

(3) Remove retaining nut.

( 4 ) Remove the potentiometer from the panel.

( 5 ) P o s i t i o n the replacement potentiometer in the panels.

( 6 ) Secure the potentiometer to panel with the retaining nut.

( 7 ) Solder the wires to the potentiometer. Use solder (item 5, table 4-1). Remove the tags.

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