Standard Notes For Servicing - Sharp DV-SL700W Service Manual

STANDARD NOTES FOR SERVICING

Circuit Board Indications
1. Removal
a. The output pin of the 3 pin Regulator ICs is indicated
With Hot-Air Flat Pack-IC Desoldering Machine:
as shown.
(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)
Top View
Out In
b. For other ICs, pin 1 and every fifth pin are indicated
as shown.
< Bottom View >
Pin 1
(2) Remove the flat pack-IC with tweezers while apply-
c. The 1st pin of every male connector is indicated as
ing the hot air.
shown.
(3) Bottom of the flat pack-IC is fixed with glue to the
CBA; when removing entire flat pack-IC, first apply
< Bottom View >
soldering iron to center of the flat pack-IC and heat
up. Then remove (glue will be melted). (Fig. S-1-6)
Pin 1
(4) Release the flat pack-IC from the CBA using twee-
zers. (Fig. S-1-6)
Caution:
Instructions for Connectors
1. Do not supply hot air to the chip parts around the flat
pack-IC for over 6 seconds because damage to the
1. When you connect or disconnect the FFC (Flexible
chip parts may occur. Put masking tape around the
Foil Connector) cable, be sure to first disconnect the
flat pack-IC to protect other parts from damage.
AC cord.
(Fig. S-1-2)
2. FFC (Flexible Foil Connector) cable should be in-
2. The flat pack-IC on the CBA is affixed with glue, so
serted parallel into the connector, not at an angle.
be careful not to break or damage the foil of each pin
or the solder lands under the IC when removing it.
CBA
Masking
Tape
* Be careful to avoid a short circuit.
Tweezers
Bottom View
Input
5
Fig. S-1-1
10
Hot-air
Flat Pack-IC
FFC Cable
Desoldering
Machine
Connector
CBA
Flat Pack-IC
Fig. S-1-2
(1) Using desoldering braid, remove the solder from all
Using lead-free wire solder
pins of the flat pack-IC. When you use solder flux
When fixing the PWB soldered with the lead-free solder,
which is applied to all pins of the flat pack-IC, you can
apply lead-free wire solder. Repairing with conventional
remove it easily. (Fig. S-1-3)
lead wire solder may cause damage or accident due to
cracks.
Flat Pack-IC
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
(2) Lift each lead of the flat pack-IC upward one by one,
may be apt to keep the soldering bit in contact with the
using a sharp pin or wire to which solder will not
PWB for extended period of time. However, Since the
adhere (iron wire). When heating the pins, use a fine
land may be peeled off or the maximum heat-resistance
tip soldering iron or a hot air desoldering machine.
temperature of parts may be excoeded, remove the bit
(Fig. S-1-4)
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
Fine Tip
on the PWB silk.
Soldering Iron
Lead-free wire solder for servicing
(3) Bottom of the flat pack-IC is fixed with glue to the
CBA; when removing entire flat pack-IC, first apply
Part No.
soldering iron to center of the flat pack-IC and heat
ZHNDAi123250E
up. Then remove (glue will be melted). (Fig. S-1-6)
(4) Release the flat pack-IC from the CBA using twee-
ZHNDAi126500E
zers. (Fig. S-1-6)
ZHNDAi12801KE
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.
5
DV-SL700W
Desoldering Braid
Soldering Iron
Fig. S-1-3
Sharp
Pin
Fig. S-1-4
Description
J 0.3mm 250g(1roll)
J 0.6mm 500g(1roll)
J 1.0mm 1kg(1roll)
Code
BL
BK
BM