Emerson SC319C Service Manual page 11

Notes:
a. Do not attempt to lift the component off the board
until the component is completely disconnected
from the board by the twisting action.
b. Take care not to break the copper foil on the
printed board
3. Installing the leadless component
a. Presolder the contact points of the circuit board.
b. Press the part downward with tweezers and solder
both electrodes as shown below.
Note:
Do not glue the replacement leadless component to
the circuit board.
Chip
Soldering Iron
Soldering Iron
Tweezers
Soldering Iron
Presolder
How to Remove / Install Flat Pack IC
Caution:
1. Do not apply the hot air to the chip parts around the
Flat Pack-IC for over 6 seconds as damage may
occur to the chip parts. Put Masking Tape around
the Flat Pack-IC to protect other parts from dam-
age. (Fig. S-1-2)
Tweezers
Solder
2. The Flat Pack-IC on the CBA is affixed with glue,
so be careful not to break or damage the foil of
each pin or solder lands under the IC when remov-
ing it.
1. Removal
With Hot - Air Flat Pack - IC Desoldering Machine:
a. Prepare the Hot - Air Flat Pack - IC Desoldering
Machine, then apply hot air to Flat Pack - IC (about
5~6 seconds). (Fig. S-1-1)
b. Remove the Flat Pack- IC with tweezers while
applying the hot air.
With Soldering Iron:
a. Using desoldering braid, remove the solder from all
pins of the Flat Pack - IC. When you use solder flux
which is applied to all pins of the Flat Pack - IC, you
can remove it easily. (Fig. S-1-3)
b. Lift each lead of the Flat Pack - IC upward one by
one, using a sharp pin or wire to which solder will
not adhere (iron wire). When heating the pins, use
a fine tip soldering iron or a hot air Desoldering
Machine. (Fig. S-1-4)
With Iron Wire:
a. Using desoldering braid, remove the solder from all
pins of the Flat Pack - IC. When you use solder flux
which is applied to all pins of the Flat Pack - IC, you
can remove it easily. (Fig. S-1-3)
b. Affix the wire to a workbench or solid mounting
point, as shown in Fig. S-1-5.
c. Pull up on the wire as the solder melts so as to lift
the IC leads from the CBA contact pads, while
heating the pins using a fine tip soldering iron or
hot air blower.
Note:
When using a soldering iron, care must be taken
to ensure that the Flat Pack - IC is not being held
by glue, or when it is removed from the CBA, it
may be damaged if force is used.
2. Installation
a. Using desoldering braid, remove the solder from
the foil of each pin of the Flat Pack - IC on the CBA,
so you can install a replacement Flat Pack - IC
more easily.
b. The "I" mark on the Flat Pack - IC indicates pin 1
(See Fig. S-1-6). Make sure this mark matches the
1 on the CBA when positioning for installation.
Then pre - solder the four corners of the Flat Pack-
IC (See Fig. S-1-7).
c. Solder all pins of the Flat Pack - IC. Make sure that
none of the pins have solder bridges.
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