Section III. REPAIR AND REPLACEMENT

TM 11-6625-601-34

Table 2-3. Voltage and Resistance Measurements for Audio Amplifier A1 (Part of SM-349/ARC-54)

Section Ill. REPAIR AND REPLACEMENT

mits, use a heat sink (such as long-nosed pliers)

2-6. General Instructions

between the soldered joint and the transistor.

The direct support maintenance procedures

Use approximately the same length and dress

given in this manual supplement the procedures

of transistor leads as used originally.

described in the operator and organizational

maintenance manual (TM 11-6625-601-12). The

2-8. Removal and Replacement of Audio

systematic troubleshooting procedure, which

Amplifier A1 (Located in TS-1967/

begins with the operational and sectionalization

ARC-54)

checks that can be performed at an organiza-

a. Remove audio amplifier A1 (fig. 210) as fol-

tional level, is carried to a higher level in this

lows:

manual.

(1) Remove the six screws, lockwashers,

and nuts (4) that secure the attenuator plate

2-7. General Parts Replacement Techniques

(5) to the test set chassis.

a. Most of the test set and simulator parts are

(2) Remove the attenuator plate (5) from

readily accessible and can be replaced easily

the test set chassis; be careful not to put too

without special procedures. To gain access to

much strain on the wire harness (6).

the interior of the test set, remove 10 screws

(3) Remove the four screws and flat

from around the edges of the front panel and

washers (1) that secure the audio amplifier

lift it from the lower case; use the two handles.

board (2) to the test set chassis.

To gain access to the interior of the simulator,

(4) Pull the audio amplifier board (2) away

remove the eight screws that secure the metal

from the chassis until the wires connected to

cover to the simulator chassis. Carefully lift the

the terminals on the bottom are accessible.

metal cover from the simulator.

(5) Tag and unsolder all wires that connect

b. Use a pencil-type iron with a 25-watt max-

the audio amplifier board (2) to the cable har-

imum capacity when replacing components con-

ness (3).

tained in transistorized circuits. If the iron

(6) Remove the audio amplifier board (2).

must be used with ac, use an isolating trans-

b. Replace audio amplifier A1 as follows:

former between the iron and the line. Do n o t

(1) Connect and solder each wire to its

use a soldering gun; damaging voltages can be

r e s p e c t i v e terminal on the audio amplifier

induced in components. When soldering transis-

board (2).

tor leads, solder quickly; whenever wiring per-

(2) Position the audio amplifier board (2) in

2-12