TM 11-5821-284-34
Sequence
Doe
Trouble Symptom
Probable Cause
Corrective Action
No.
Test
f. Incorrect voltage at
Defect in A1A6.
Check A1A6 and A1R32.
A1A6B-7 when
MANUAL TUNE switch
is set to DECREASE
FREQUENCY.
g. Incorrect voltage at
Defect in AlQ16.
Check AlQ16 and A1R28.
A1Q16 collector when
MANUAL TUNE switch
is set to DECREASE
FREQUENCY.
h. Incorrect voltage at
Defect in AlA6.
Check AlA6 and A1CR26.
A1A6B-7 when MANUAL
TUNE switch is set to
INCREASE FREQUENCY.
i. Incorrect voltage A11
Defect in A1A6.
Check AlA6 and A1R11.
AlA6, C- 1 when
MANUAL TUNE switch
is set to INCREASE
FREQUENCY.
Defect in A1A6.
j. Incorrect voltage at
Check A1A6.
A1A6A-3 when MANUAL
TUNE switch is set to
INCREASE FREQUENCY.
k. Incorrect voltage at AlA16
Defect in AlQ15.
Check AlQl6 and AlR30.
collector when MANUAL
TUNE switch is set to
INCREASE FRE-
QUENCY.
Section II. General Support Repair and Replacement
differences in individual units.
4-6.
General
4-7.
Disassembly of Coupler Assembly (Fo 6-6)
a. Careless or incorrect repair or replacement
a. Removal of Components on Servo Amplifier
of parts can cause more damage and trouble than the
Card Al.
original defect. Before unsoldering a part, note the
position of the leads and parts involved. Make notes and
(1) Remove cover MP11 by loosening
sketches of the original location and placement of parts
four screws MP11H4 and two screws MP11H2.
and lead wires to assure proper lead wire dress and
(2) Separate servo amplifier card Al from
parts location to du-plicate the original condition. This
backing plate MP21 by removing five screws Al-H5 and
procedure also minimizes the possibility of wiring errors.
one screw AiH1. Nut and washer MP6H1 and loop
b. When soldering transistors, use a heat sink
clamp MP6 are attached to screw AlH1.
(a pair of pliers or a large alligator clip) between the
(3) Remove the desired component.
transistor leads and the connection terminals.
NOTE
Transistors are sensitive to heat. Overheating during
If removal of servo
soldering operations may change their characteristics or
amplifier card Al is
permanently damage them. Use a low wattage iron to
necessary,
unsolder
solder or unsolder all con-nections, except ground
and code all wires
connections made directly to the chassis. For ground
attached to the card.
connections to the chassis, use a 100-watt iron. When
b. Removal of Components from Phase
soldering, ap-ply the soldering iron only long enough to
Discriminator Board A2.
assure a good joint When unsoldering, do not apply the
(1) Remove four screws, lockwashers and
soldering iron to the joint any longer than nec-essary to
nuts A2H4.
melt the solder. Hasten cooling by dip-ping a soft brush
(2) Carefully position phase discriminator
in alcohol and applying it to the joint.
board A2 away from the unit to obtain access to
4-6
components on the board.
c. In replacing components, refer to the MCN
Effectivity List (paragraph 1-5) for information on
4-6
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