Troubleshooting Chart - TM-11-5820-549-50-10010

TM 11-5820-549-50-1

it must have good voltage regulation and low ac ripple.

2-5. Troubleshooting Chart

Good regulation is important because the output voltage

a. Use of Chart. The more common troubles are

of the battery eliminator (which has poor regulation) may

listed in the troubleshooting chart below.

If the

exceed the maximum voltage rating of the integrated

operational symptom is known, locate the symptom in

circuits in the equipment being tested. A battery

the Indication column.

eliminator that has poor ac filtering will create a false

b. Conditions for Tests. All voltage checks in the

indication of poor filtering in the equipment being tested.

chart are to be made with the PP-3514/U connected to

b. Test harness for connecting the power supply to

the receiver (para 2-4). All resistance measurements

the AN/PRR-9(XE-9) can be made by using the

and continuity checks are to be made without power to

connector from a discarded Battery, Dry BA-4534/U, or

the receiver and the ohmmeter on a higher than X1

a similar connector such as Switchcraft Micro-Jack type

range.

TR2A. Either of these connectors will fit the battery

c. Troubleshooting Chart

connector of the AN/PRR-9(XE-9). The tip of the

battery connector is B + and the sleeve is B-.

Indication

Probable trouble

Procedure

1 No audio

a. Defective J5

a. Examine J5 for open switch

element. Replace J5 if

required (pars 3-2).

b. Defective Z3

b. Measure voltages and resistances

at Z3 (para 2-6).

2 Audio received with headset,

a. Defective LS1

a. Replace LS1.

but not with horn transducer.

b. Defective J5

b. Examine J5 for proper action of

switching element. Replace

J5 if required (para 24).

3 No squelch

a. Misalinement

a. Realine (para 3-3 through 3-8).

b. Defective Z4

b. Measure voltages and resistances

at Z4 (para 2-6).

c. Defective S1

c. Make continuity test of S1. Replace

control assembly, if S1 is faulty

(fig. 2-4).

4 Weak reception

a, Misalinement

a. Realine (para 3-3 through 3-8).

b. Defective antenna connector J2

b. Mechanically adjust or replace J2.

c. Defective Z1

c. Measure voltages and resistances

at Z1 (para 2-6).

d. Defective Z2

d. Measure voltages and resistances

at Z2 (para 2-6).

5 No reception

a. Misalinement

a. Realine (para 3-3 through 3-8).

b. Defective Y1

b. Replace Y1 (fig. 2-2).

c. Defective Z1

c. Measure voltages and resistances

at Z1 (para 2-6).

d. Defective Z2

d. Measure voltages and resistances

at Z2 (para 2-6).

board. Positive connection is made to the indicated

2-6. Voltage and Resistance Measurements

pad. All voltages shown on the chart are positive unless

a. General. All measurements are made with the

marked with a negative sign (-). Set the PP-3514/U for

electronic unit assembly removed from the case (TM

3.2 volts. All voltage readings within 10 percent of

11-5820-549-12-1).

Voltage

and

resistance

those shown should be considered normal.

measurements are given for all significant circuit points.

Identification of integrated circuit elements is given in

c. Resistance Measurements.

All resistance

the schematic diagram, figure 4-10 and in the table in

measurements are made with the negative side of the

paragraph 1-16. For identification of printed circuit

multimeter connected to ground of the printed circuit

board pads refer to figure 2-1.

board. Resistance measurements in circuits where

integrated circuit elements are located may be expected

b. DC Voltage Measurements.

All voltage

to vary considerably from the typical values shown.

measurements are made with the negative side of the

TS-352B/U connected to ground of the printed circuit

2-2