Localizing Troubles-CONT. - TM-11-6625-667-450065

TM 11-6625-667-45/NAVSHIPS 0969-249-8010/NAVAIR 16-30APM123-2/TO 33A1-3-367-22

Corrective measures

Probable trouble

Symptom

a. Video enable DFF6------------- a. Check transistors A9Q1 and A9Q2

Video-enable DFF6 output at test

socket resistances.

b. Diode A9CR7, A9CR8, or A9CR9.

point A9TP4 abnormal during all

b. Check diodes.

modes.

Video-enable output at test point

A9TP4 abnormal only during one

of the tests listed in a, b, and c

below (the line-drive enable output

(A9TP3) and M1 timing pulse at

test point A10TP3 were normal

during sectionalization tests).

a. I/P (except mode 1)-------------- a. Counter section DFF3 or train a. Check socket resistances at transis-

plus I/P reset gate.

tors A9Q8 and A9Q9. If normal,

check gate diodes A9C R5 and

A9CR6.

b. I/P mode l---------------------- b. Counter sections DFF3 and DFF4, b. Check socket waveforms at transis-

tors A9Q8 through Q9Q11 to

or 2-train reset gate.

isolate faulty stage. If normal,

check gate diodes A9CR3 and

A9CR4.

c. Emergency (I/P mode 1 normal) --- c. Train plus 3 FPS reset gate -------- c. Check gate diodes A9CR1 and

A9CR2.

Line-drive enable DFF1 output at

test point A9TP3 is abnormal as

indicated by a, 6, and C below.

a. Delay-enable pulse input transistor

a. Perform the following:

a. Locked in low state (does not

A9Q6 or A9Q7.

(1) Check waveform at test point

set).

A5TP3 (encoder module A5,

fig. 8-36). If normal, proceed

with (2) below; if abnormal,

refer to encoder modules A4

and AS troubleshooting chart

(f. above).

(2) Check socket resistances of

transistors A9Q6 and A9Q7

(fig. 3-15).

b. Perform the following:

b. Looked in a high state (does not

b. Line-drive pulse reset input; tran-

(1) Check waveform at test point

sistor A9Q6 or A9Q7.

reset).

A1OTP4 (fig. 8-36). If nor-

mal, proceed with (2) below.

If abnormal, refer to decoder

module A10 troubleshooting

chart (j below).

(2) Check socket resistances of

transistors A9Q6 and A9Q7.

c. Check the following:

c. Perform the following:

c. During I/P and emergency tests,

(1) Ml timing pulses ------------

(1) Check M1 pulse waveform at

after line-drive enable DFF1 is

reset by first line-drive pulse,

test point A10TP3 (fig. 8-

it does not set (go high) again.

36). If abnormal, refer to

troubleshooting procedures in

chart j below. If normal, pro-

ceed with (2) below.

(2) Diode A9CR16 or A9R35 ----

(2) Check diode A9CR16 and

(3) FUNCTION switch A15S6

resistor A9R35. If normal,

section C.

check wiring and continuity

of MODE switch A15S5,

section C (fig. 8-16).

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