b. General test procedures.
You must determine the type of test and
identify the test points for these tests. Troubleshooting techniques for a
return power circuit defect are circuit substitution, followed by voltage
measurements and continuity checks (Figure 50).
c. Test procedure 23.
The first test point (TP1) is at J24 on the MT-
1029 (Figure 50).
Remove the RT from the MT-1029.
Using extreme CAUTION, insert an insulated jumper wire between
pins B and C J24.
If the AM-1780 power lamp lights, the RT unit is bad.
Send to
IDS for repair.
d. Test procedure 24. If the AM-1780 power lamp does not light, the
next check (TP2) is at the end of the CX-4723 P501 pins A and C.
Remove the CX-4723 from the AM-1780
J501.
Measure
voltage
between pins A and C on CX-4723 P501.
If the meter indicates 22-30 volts DC, the AM-1780 is bad.
Send
to IDS for repair.
e. Test procedure 25. If the meter indicates no voltage at TP2, remove
the jumper from J24 then test continuity between pin C of J24 and pin C of
J22 on the MT-1029 (TP3).
The MT-1029 must be disassembled to reach pin C of jack J22.
If the resistance measurement between pin C of J24 and pin C of
J22 indicates infinite ohms, the MT-1029 is bad. Repair it, if
possible, if not send to IDS for repair.
If the meter indicates zero ohms, the MT-1029 is good.
f. Test procedure 26.
Measure continuity from pin C to pin C, through
the CX-4723 (TP4).
Remove the CX-4723 from J7 of the J-3513, and test continuity
from pin C to pin C through the CX-4723.
If the meter indicates infinite ohms, the CX-4723 is bad repair
or replace.
If the meter indicated zero ohms, the CX-4723 cable is good and
the J-3513 is bad.
Turn J-3513 in to the COMSEC support
maintenance for repair.
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