TM 9-6115-669-13&P
RECEPTACLE J20 AND VARISTORS R7, R8
a.
Record labeling and position of cables on receptacle (46, figure 5-21).
b.
Remove cable of resistor R7 (25, figure 5-20) and cable of resistor R8 (26) from pin J20-A of
receptacle (45, figure 5-21).
c.
Push pins with cables out of receptacle.
d.
Remove screws (42), washers (43), nuts (49), serrated lock washers (48), washers (47) and
remove receptacle (44,45) and gasket (46).
e.
Remove nut (16, figure 5-20), serrated lock washer (17), washer (18), and cable (29) of resistor
R7 (25), and cable (29) of resistor R8 (26) from grounding stud.
INSPECTION
Inspect receptacles, cables and varistors for damage and discoloration due to excessive heat.
A damaged varistor is generally short cicuited and must be replaced.
TEST
NOTE
l Varistors protect electric circuits from being damaged by high
voltage peaks (i. e. lightnings). Presence of high energetic pulses
causes varistors to decrease their normally high resistance and
change to a conductive status until the voltage peaks become
harmless.
l For resistors R7 (25, figure 5-20), R8 (26), R11 (24), R12 (22), R13 (23)
and R14 (27) the test procedure is the same.
a.
Use multimeter and check resistance. If measured resistance is less than 1 MOhm the varistor
is defective and must be replaced.
REPAIR
NOTE
This procedure is the same for receptacle J1 to J4.
a
Cut new cables to length and strip both ends of cables as instructed in Appendix G. Install
new pins, cable marker, lugs and new heat shrinks. Number the heat shrinks accordingly.
b.
Solder cable into connector.
5 - 5 6
