Service manual

2-8 Samsung Electronics
2-3 Chip Replacement (SMD parts)
2-2-1. Precautions for Chip Replacement
1. See to it that the soldering iron does not touch
parts directly. In particular, TSOP may be easily
damaged by heat.
2. Handle the soldering iron with care and avoid
using the same many times. Some parts can be
damaged by sudden heat. Preheat parts for min-
utes at about 100¡c before soldering them.
3. The temperature of the soldering iron should
remain at about 240¡c Use a 280¡c iron for
bigger parts.
4. Thin (0.3mm) solder used for chip parts does not
contain enough flux. Use additional flux.
* For computers and OA systems, water-soluble flux
is used. Water-soluble flux and solder are also
good for replacing parts and repairing this prod-
uct. Improper flux may corrode the soldered part
and cause serious defects to the system.
5. Be careful not to damage the circuit pattern when
you disjoin soldering. The pattern should be clean
because there are a lot of pins close together on IC.
6. Be careful not to cause a short circuit between
close pins.
7. Locate parts in place. It has a great influence on
soldering.
8. Do not use repaired parts again.
9. Check the soldered part.
10. Defective variable resistors are not adjustable. Be
sure to replace them.
11. After finishing the job, check if there are cold sol-
dered parts.
2-2-2. Tools to Replace Chips
The following tools are used to replace chip parts.
¥ iron with thin tip
¥ iron with small and flat tip
¥ solder remover
¥ ventilation device
¥ tools to lift flat parts
¥ flux that can be cleaned with water
¥ 0.3mm thin solder that can be cleaned with water
¥ wire to remove solder
¥ tweezers
2-2-3. Chip Resistance & Chip Condenser
2-2-3 (a) Type
There are the following types of chip resistance and
chip condensers.
¥ There are the following types of thin film and chip
condensers.
¥ Carbon Film chip resistance
¥ Metal Film chip resistance
¥ Chip ceramic condenser
¥ Chip variable resistance
2-2-3 (b) Removal
Use 2 soldering irons.
a. Use a thin-tip iron.
b. Keep about 280¡c
c. Apply heat to both ends of a part at the same time.
d. Remove it with the tip of the iron while heating.
e. Remove the remaining solder on PCB completely
with solder removing wire. It should be done to
install a new part.