Troubleshooting Chart.

TM 11-6625-1702-35

b. Troubleshooting Chart.

Item

Symptom

Probable trouble

Correction

Test procedure

No.

1 Dc meter scale test a. Meter indication of 28- a. R2 or M1 defective ---- a. Replace defective com-

ponent.

volt dc input high.

(para 4-5).

b. Meter indication of 28- b. R2, C1, M1, or S3 defec- b. Perform resistance and

tive or there is a

continuity checks ( para

volt dc input low.

short in the associated

27b) to locate the de-

fect. Replace defective

circuits.

component.

C. Perform

resistance and

c. Meter indication zero --- c. F1, R2, M1, or S3 defec-

tive or there is an

continuity checks to lo-

open circuit in the 28-

cate the defect. Replace

volt dc line.

defective component.

2 Millivolt source test a. Voltage at MV OUT- a. CR1 defective ---------- a. Replace CR1.

PUT terminals very

(para 4-6).

unstable.

b. MV OUTPUT voltage b. R4, R5, R1, or CR1 b. Perform resistance checks

to locate defective com-

defective.

zero.

ponents. Replace defec-

tive component.

C. MV OUTPUT voltage

c. C1 or M1 defective ____ c. Replace defective compo-

nent.

correct but meter in-

dication is excessively

high or low.

I N D I C A T O R a. DS1, Q3, Q2, or R12 a. Check TUNE INDICA-

3 TUNE INDICA- a. T U N E

TOR DS1. Check re-

defective.

TOR

function

does not light.

sistance of R12. Per-

test (para 4-7).

form voltage and re-

sistance measurements

(para 2-7c) on Q3 and

Q2. Replace defective

component.

b. TUNE

INDICATOR b. CR2, CR3, CR4, Q2, b. Perform resistance checks

and voltage and resist-

Q3, R9, R10, R11,

does not extinguish

ance measurements as

R12, or C2 defective.

when coupler is con-

required to isolate de-

nected and MV AD-

fective component. Re-

JUST control is fully

place defective com-

counterclockwise.

ponent.

c. TUNE

INDICATOR c. CR2, C2, Q2 or Q3 de- c. Perform voltage and re-

sistance measurements

fective.

does not illuminate

as required to isolate

brightly.

malfunction. Replace de-

fective component.

d. Repetition rate too slow d. Q1 defective ---------- d. Replace Q1.

(greater than 20 ms)

when TUNE INDI-

CATOR reaches full

brilliance.

4 Coupler test (para a. Coupler does not cycle __ a. Z1, S1, or associated a. Perform continuity checks

on wiring, connectors,

connectors or wiring

4-8 ) .

and S1. Repair or re-

defective.

place as required. If no

defects are found in S1

or the associated wir-

ing, replace Z1.

2-5