Figure 2-28. Component bracket on test unit chassis, showing location of parts.

TM 11-6625-564-45

Figure 2-28. Component bracket on test unit chassis,

showing location of parts.

resistance measurement diagram for audio am-

2-8. localizing Troubles

plifier 3A1 is figure 2-29. Chassis resistance

a. General Instructions. In the trouble-

and continuity measurement procedures for the

shooting chart in b below, procedures are out-

test unit are given in paragraph 2-7c. If op-

lined for localization of trouble by operation

erational symptoms are not known or if they

of the test unit with the radio set simulator in

indicate possibility of short or open circuits,

a self-testing mode. Connect the equipment

make the resistance and continuity tests indi-

as shown in the interconnecting block diagram

cated in paragraph 2-7c before proceeding.

in figure 3-1, TM 11-6625-564-12. The parts

Note: If the symptoms indicate trouble in audio am-

locations of the test unit are given in figures

plifier 3A1, proceed to paragraph 2-8c before making

2-23 through 2-28. The test unit voltage and

voltage and resistance measurements.

Correction

Step No.

Symptom

Replace lamps.

Lamps may be burned out.

Indicator lamp does not

light.

a. Replace CB1.

a. POWER switch CB1 is defective.

a. T/R lamp does not light

when Function SE-

LECT switch S4 is

Replace S4.

FUNCTION SELECT switch

set to T/R.

S4 is defective.

When

lamps

are

not

b. POWER switch CB1 is defective.

b. Replace CB1.

burned h. T/R&G lamp does not

Replace S4.

FUNCTION SELECT switch

out.

light when FUNC-

S4 is defective.

TION SELECT

switch S4 is set to

T/R+G.