Localizing Troubles-CONT. - TM-11-6625-667-450064

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

f. Decoder Module A7 Troubleshooting. Transistor socket voltages (if applicable) and resistances

are shown in figure 3-13. Socket waveforms are shown in figure 8-19. Schematic diagram is figure 8-10.

Corrective measures

Probable trouble

Symptom

All information pulses missing, as

Information inhibit gate-------------- Check socket resistances at transistor

A7Q16; check gate diodes A7CR1 and

observed at test point A10TP2;

A7CR2.

F2 and I/P pulses are present.

Check socket waveforms, voltages, and

One or more information pulses, but Transistor associated with pulse.

resistances at the applicable

Listing is correlated with pulse

not all, are missing at test point

transistor. Check CODE switch

identification given in the Symptom

A10TP2. Pulses are identified

(A15S2 and A15S3) operation, if

column.

as follows :

transistors are normal.

a . A 7 Q 1 - - - - - - - - - - - - - - - - - - - - - - - - - - Substitute anew module A6 (delay line).

a. Cl - - - - - - - - - - - - - - - - - - - - - - - - - -

b. A7Q2

b. C2 - - - - - - - - - - - - - - - - - - - - - - - - - - -

c. C4- - - - - - - - - - - - - - - - - - - - - - - - - - -

c. A7Q3

d. A7Q4

d. D1 - - - - - - - - - - - - - - - - - - - - - - - - - - -

e. A7Q5

e. D2- - - - - - - - - - - - - - - - - - - - - - - - - - -

f. A7Q6

f . D4 - - - - - - - - - - - - - - - - - - - - - - - - - - -

g. Al - - - - - - - - - - - - - - - - - - - - - - - - - - -

g. A7Q7

h. A2- - - - - - - - - - - - - - - - - - - - - - - - - - -

h. A7Q8

i. A7Q9

i. A4 - - - - - - - - - - - - - - - - - - - - - - - - - -

j. B1 - - - - - - - - - - - - - - - - - - - - - - - - - - -

j. A7Q10

k. A7Q11

k. B2 - - - - - - - - - - - - - - - - - - - - - - - - - - -

1. A7Q12

l. B 4 - - - - - - - - - - - - - - - - - - - - - - - - - - -

F2 pulse missing------------------- Transistor A7Q13-------------------- Check socket voltage and resistances.

I/P pulse missing------------------- Transistor A7Q15-------------------- Check socket voltages and resistances.

Transistor A7Q14-------------------- Check socket voltages and resistances.

Ml pulse abnormal as observed at

test point A10TP3.

All pulses missing as observed at

Delay line -------------------------- Replace delay-line module A6.

A10TP3, but line-drive pulse is

normal at A10TP4.

g. Receiver Section, Video Module A8 Troubleshooting. Transistor socket voltage and resistances are

shown in figure 3-14; schematic diagram is figure 8-11.

Probable trouble

Corrective measures

Symptom

a. Sensitivity adjustment - - - - - - - - - - - - - a. Adjust receiver sensitivity control

Less than +7 volts at test point

A8R5 until ACCEPT indicator

A8TP2 with normal RF signal at

just lights with a 9 dbm RF

PROBE jack,

input at the PROBE jack.

Check socket voltages and

b. Transistor A8Q1, A8Q2, A8Q3, or b.

A8Q4.

resistances.

Check diode A15Z2CR1.

c. Detector diode -----------------------------------C.

Video gate 2 - - - - - - - - - - - - - - - - - - - - - - - - a.

Check socket resistance at transis-

Video shaper output at test point

tor A8Q9.

Al1TP1 abnormal; waveforms

If transistor appears normal, refer

are normal at test point A8TP2

to chart, first item, in sub-

and video-enable output (test

paragraph j below.

point A9TP5).

h. Decoder Module A9 Troubleshooting.

Note 1. Transistor socket resistance and waveforms are shown in figures 3-15 and 8-20, respectively.

Note 2. Test point waveforms are shown in figure 8-36.

Note 3. The schematic diagram is figure 8-12.

Note 4. It is assumed that waveforms at test points A10TP4 and A10TP6 were normal during the sectionalization

tests. Also that mode 2 interrogation signals (transmitter section) were normal.

3-19