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Then solder its pins or leads. If the lead or pin connects to a
large area of printed foil, apply the soldering tip for 5 or 6
seconds.
WARNING: USE ETHYL ALCOHOL (OR ISOPROPYL ALCOHOL) ONLY IN WELL
VENTILATED AREAS.
(9) Completely clean the soldered area of the printed circuit card
assembly with alcohol or water and a toothbrush.
(10) Remove all residual substances from the printed circuit card
assemblies using a dry brush or cloth.
(11) Apply a layer of insulating compound on the body and leads or pins
of the replacement component and on the soldered areas of the
printed circuit card assembly. If you use an aerosol spray, attach
masking tape to the areas other than the replacement component and
the soldered areas. Obey the rules given below:
(a) Apply a layer of insulating compound only after you make sure
that the replacement component corrected the problem.
(b) Apply a layer of insulating compound to the areas where the
layer was removed during the repair.
(c) Obey the instructions of the insulating compound manufacturer to
correctly apply and dry the insulating compound.
(12) If the removed component was safetied with hot-melt glue or the hotmelt
glue was removed for the replacement work, apply hot-melt glue
as it was with a hot-melt glue gun.
Page 606
Feb 20/2002
Panasonic Avionics Corporation
COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
23-32-47
B. Repair of Printed Circuit Card Assemblies
(1) Bypass the damaged printed conductors with jumper wire. Use Tefloninsulated
copper wire that agrees with the wire description given in
2. above.
(2) Resolder the broken soldered connections to repair such connections.
(3) Apply a layer of insulating compound after you repaired the area
where a layer of insulating compound was applied. If you use an
aerosol spray, put masking tape on the areas where it is not
necessary to apply a layer of insulating compound.
(4) Obey the instructions given below when you apply a layer of
insulating compound:
(a) Apply a layer of insulating compound only after you make sure
that the repair corrected the problem.
(b) Apply a layer of insulating compound to the areas where the
layer was removed during the repair.
(c) Obey the instructions of the insulating compound manufacturer to
correctly apply and dry the insulating compound.
C. Small Chip Components
The small chip components are chip resistors, chip capacitors, chip
transistors and equivalent devices. Replace a small chip component
(chip) as follows:
(1) Fully desolder each electrode of the chip.
(2) Hold the non-electrode sides of the chip with tweezers, apply heat
to each electrode one after the other with a soldering iron, and
turn the tweezers to remove the chip. Refer to Figure 601.
NOTE: The chip was bonded to the printed circuit card during the
manufacturing. The above step loosens the adhesive with heat
to make the removal of the chip easier.
(3) Discard the removed chip. You cannot use the removed chip again.
(4) Fully clean the chip removed area and soldering positions.
(5) Before you put a new replacement chip in position, put a sufficient
quantity of solder on each soldering position.
Page 607
Feb 20/2002
Matsushita Avionics Systems Corporation
COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
23-32-47
TWEEZERS
APPLY HEAT
APPLY HEAT
SOLDERING IRON
REMOVAL OF SMALL CHIP COMPONENT
Figure 601
(6) Hold the non-electrode side of the replacement chip with tweezers
and put the replacement chip on the soldering positions.
CAUTION: DO NOT APPLY HEAT TO THE CHIP LONGER THAN 3 SECONDS. DO NOT RUB
THE ELECTRODE OF THE CHIP WITH THE TIP OF THE SOLDERING IRON.
HEAT OR FORCE CAN EASILY LOOSEN THE ELECTRODES OF THE CHIP.
(7) Move the tip of the soldering iron in the direction to the electrode
to solder each electrode. Refer to Figure 602.
CHIP
SOLDERING IRON
SOLDER
HOW TO SOLDER A SMALL CHIP COMPONENT
Figure 602
Page 608
Feb 20/2002
Matsushita Avionics Systems Corporation
COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
23-32-47
D. Small Flat-Package IC Devices
Obey the instructions given below to remove a small flat-package IC
device:
(1) Remove the solder from all pins of the IC device.
(2) Lift the pins one after the other with a very thin hook (a sewing
needle with its pointed end bent 90° will do) while you apply heat
with a soldering iron.
(3) Remove the IC device when all of the pins are lifted.
E. Large Flat-Package IC and Equivalent Devices
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COMPONENT MAINTENANCE MANUAL Video Modulator Unit (VMU)(86)
