Sharp DV-SL700W, Руководство по обслуживанию

Страница: 5 / 72

DV-SL700W
5
STANDARD NOTES FOR SERVICING
Circuit Board Indications
a. The output pin of the 3 pin Regulator ICs is indicated
as shown.
Top View
Out In
Bottom View
Input
b. For other ICs, pin 1 and every fifth pin are indicated
as shown.
5
10
Pin 1
< Bottom View >
c. The 1st pin of every male connector is indicated as
shown.
Pin 1
< Bottom View >
Instructions for Connectors
1. When you connect or disconnect the FFC (Flexible
Foil Connector) cable, be sure to first disconnect the
AC cord.
2. FFC (Flexible Foil Connector) cable should be in-
serted parallel into the connector, not at an angle.
FFC Cable
Connector
CBA
* Be careful to avoid a short circuit.
Using lead-free wire solder
When fixing the PWB soldered with the lead-free solder,
apply lead-free wire solder. Repairing with conventional
lead wire solder may cause damage or accident due to
cracks.
As the melting point of lead-free solder (Sn-Ag-Cu) is
higher than the lead wire solder by 40
°
C, we recommend
you to use a dedicated soldering bit, if you are not
familiar with how to obtain lead-free wire solder or
soldening bit, contact our service station or service
ranch in your area.
Soldering
As the melting point of lead-free solder (Sn-Ag-Cu) is
about 220
°
C which is higher than the conventional lead
solder by 40
°
C, and as it has poor solder wettabillty, you
may be apt to keep the soldering bit in contact with the
PWB for extended period of time. However, Since the
land may be peeled off or the maximum heat-resistance
temperature of parts may be excoeded, remove the bit
from the PWB as soon as you conurm the steady
soldering condition.
Lead-free solder contains more tin, and the end of the
soldering bit may be easily corroded. Make sure to tum
on and off the power of the bit as required. if a different
type of solder stays on the tip of the soldering bit, it is
alloyed with lead-free solder. Clean the bit after every
use of it.
When the tip of the soldering bit is blackened during
use, file it with steel wool or fine sandpaper.
Becareful when replacing parts with polarity indication
on the PWB silk.
Lead-free wire solder for servicing
Part No. Description Code
ZHNDAi123250E J 0.3mm 250g(1roll) BL
ZHNDAi126500E J 0.6mm 500g(1roll) BK
ZHNDAi12801KE J 1.0mm 1kg(1roll) BM
1. Removal
With Hot-Air Flat Pack-IC Desoldering Machine:
(1) Prepare the hot-air flat pack-IC desoldering ma-
chine, then apply hot air to the Flat Pack-IC (about 5
to 6 seconds). (Fig. S-1-1)
Fig. S-1-1
(2) Remove the flat pack-IC with tweezers while apply-
ing the hot air.
(3) Bottom of the flat pack-IC is fixed with glue to the
CBA; when removing entire flat pack-IC, first apply
soldering iron to center of the flat pack-IC and heat
up. Then remove (glue will be melted). (Fig. S-1-6)
(4) Release the flat pack-IC from the CBA using twee-
zers. (Fig. S-1-6)
Caution:
1. Do not supply hot air to the chip parts around the flat
pack-IC for over 6 seconds because damage to the
chip parts may occur. Put masking tape around the
flat pack-IC to protect other parts from damage.
(Fig. S-1-2)
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 the solder lands under the IC when removing it.
Hot-air
Flat Pack-IC
Desoldering
Machine
CBA
Flat Pack-IC
Tweezers
Masking
Tape
Fig. S-1-2
(1) 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)
Flat Pack-IC
Desoldering Braid
Soldering Iron
Fig. S-1-3
(2) 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)
Fine Tip
Soldering Iron
Sharp
Pin
Fig. S-1-4
(3) Bottom of the flat pack-IC is fixed with glue to the
CBA; when removing entire flat pack-IC, first apply
soldering iron to center of the flat pack-IC and heat
up. Then remove (glue will be melted). (Fig. S-1-6)
(4) Release the flat pack-IC from the CBA using twee-
zers. (Fig. S-1-6)
With Iron Wire:
(1) 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)
(2) Affix the wire to a workbench or solid mounting point,
as shown in Fig. S-1-5.
(3) While heating the pins using a fine tip soldering iron
or hot air blower, pull up the wire as the solder melts
so as to lift the IC leads from the CBA contact pads
as shown in Fig. S-1-5.