Samsung DVD-807K, Service Manual

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2-2 Samsung Electronics
2-2 Chip Replacement
1) Do not touch the part body directly with the sol-
dering iron. ICs, especially TSOP, are easily dam-
aged by heat.
2) Use care regarding soldering iron tip and avoid
repidly heating parts. Some parts can be damaged
by sudden heating. Preheat the part at about
100°… for several minutes before installing it.
3) Use soldering tip temperature of about 240°… or
larger parts, use a slightly higher temperature
(about 280°…).
4) The thin(0.3mm)solder for miniature parts does
not contain adequate flux. Supplementary flux is
thus needed in most cases.
5) Use care not to damage the circuit pattern, espe-
cially when removing.
6) Because of the many pins, cleanliness of the pat-
tern is extremely important after removing the IC.
7) Use care to avoid solder bridges. Remove any that
occurs.
8) Position the part carefully. They will also affect the
soldering operation. Be very precise in positioning
the IC. Soldering opposite pins first holds the IC in
place and makes soldering the other pins easier.
9) Do not reuse removed parts.
10) Check for solder joints, especially miniature parts
with small lead.
11) A defective trimming resistor cannot be adjusted
externally. Replace with an ordjnary variable resis-
tor.
12) It is important to inspect the work with a magnifier.
Check after installing (cold solder joints, etc.).
2-2-1 Precaution for the chip Replacement
The tools for the chip replacement are as follows:
1) Thin tip type soldering iron
2) Small flat-blade tip-type soldering iron
3) Special desoldering tip iron
4) Airblower unit
5) Flat Package Pick-up
6) Flux can be cleaned by water
7) 0.3mm thin solder can be cleaned by water
8) Desoldering wire
9) Tweezers
2-2-2 Tools for the Chip Replacement
2-2-3 Chip Resistors and Chip Capacitors
-- Kind of the Part
The kind of chip resistors and chip capacitors as follows:d
1) Think Film Chip Resistors
2) Carbon Film Chip Resistors
3) Metal Film Chip Resistors
4) Chip Ceramic Capacitors
5) Chip Trimming Resistors
-- Removing the Part
1) Using two soldering irons:
Use thin tip soldering irons.
Use soldering tip temperature of about 280°….
Simultaneously heat both ends of the part.
While heating, grasp the part with the tips of the
soldering irons and remove it.
Use desoldering wire to completely remove the old
solder from the part location of the board.
A clean pattern for installing the new part is very
important.
Fig 2-2
-- Installing the Part
1) Use desoldering wire to remove the previous solder.
2) Clean the location.
3) Apply flux.
4) Position the IC and solder two pins at opposite sides.
5) Use a sharp tipped soldering iron and carefully
solder each Pin.(After gaining experience, a thicker
tip can be used for better work efficiency.)
6) Remove any solder bridges with desoldering wire.
7) Inspect the work with a magnifier.
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