Localizing Troubles-CONT. - TM-11-6625-667-450066

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

Corrective measures

Probable trouble

Symptom

M2 inverter, error blanking DFF2, or Check socket waveforms at transistors

Error blanking pulse at test point

FUNCTION switch A15S6,

A9Q3, A9Q4, and A9Q5 (fig. 8-20).

A12TP4 abnormal, but error

section G.

Check socket resistances of sus-

blanking gate (module A12) is

pected stage. If alI three transistors

normal.

appear normal, check FUNCTION

switch.

i. Decoder Module A10 Troubleshooting. Transistor socket resistances and waveforms are shown in

figures 3-16 and 8-21, respectively. Test point waveforms are shown in figure 8-36. The schematic

diagram is figure 8-13.

Corrective measures

Probable trouble

Symptom

Video-enable delay waveshape abnor- a. A d j u s t m e n t - - - - - - - - - - - - - - - - - - - - - - a. Adjust control A10R7 (fig. 3-7) for

pulse width of 1.8 sec 0.05.

mal at test point A10TP5.

b. Video-enable delay DSS4---------- b. Check socket resistances of transistors

A10Q1 and A10Q2 (fig. 3-16).

c. Check leakage of capacitor A 10C3.

c. Capacitor A10C3, resistor A10R6,

or variable resistor A10R7.

Check value of resistor A1OR6 and

c o n t r o l A10R7.

Line-drive pulse abnormal at test

Line-drive gate 1 or 2; A10Q7--------- Check socket waveforms at A10Q5,

point A10TP4; line-drive enable

A10Q6, and A10Q7 to locate faulty

output high DFF1 is set as indi-

stage. Check socket resistances of the

stage and gate diodes as applicable.

cated at test A9TP3.

Module A7------------------------- Refer to decoder module A7 trouble-

M1 timing pulse abnormal at test

shooting procedures in g above for M1

point A1OTP3 (fig. 8-36).

timing pulse symptom.

Delay-line pulse input at test point

Module A7------------------------- Refer to decoder module A7 trouble-

shooting procedures in g above for

A10TP2 abnormal.

applicable delay-line pulse output

symptom.

Delay-1ine output amplifier A10Q10/ Delay-line output amplifier- ---------- Check socket resistances of transistors

Al0Ql1 output at test point

A10Q10 and A10Q11.

A10TP1 is abnormal; input at test

point A10TP2 is normal.

Read delay DSS5 output at test

R e a d o u t delay DSS5-------------- Check socket resistances of transistors

A10Q3 and A10Q4.

point A1OTP6 abnormal; video-

enable delay at test point A10TP5

normal.

j. Decoder Module All Troubleshooting. Transistor socket resistances are provided in figure 3-7

and waveforms are provided in figure 8-14. Test point waveforms are in figure 8-36. The schematic

diagram is figure 8-14.

Symptom

Probable trouble

Corrective measures

Video shaper DSSl output at test

a. Video gate 2 input--------------- a. Refer to subparagraph h above.

point Al1TP1 abnormal.

Symptom is similarily described.

b. A11Ql or A1lQ2------------------ b. Check transistor socket resistances.

c. Pulse width adjustment---------- c. Adjust control Al1R6 for pulse

width of 0.7(+0.0, -0.05) sec.

a. Check socket resistances of transis-

Comparison pulse shaper output at

a. Video shaper DSS1, gate diode

test point Al1TP2 abnormal.

A11CR5, or gate diode A11CR6.

tom Al1Q3 and A11Q4; if normal,

check diodes Al1CR5 and A11CR6.

b. Pulse width adjustment------------ b. Adjust control Al1R15 for pulse

width of 0.5 sec 0.01.

3-21