Sharp Aquos LC-26GD7E, Service Manual

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Precautions for using lead-free solder
1. Employing lead-free solder
„LCD CONT PWB“,“TMDS RX PWB“,“KEY PWB“,“R/C LED PWB“,“MOTOR PWB“,“INV PWB“,“POWER
PWB“of this model employs lead-free solder. The LF symbol indicates lead-free solder, and is attached on
the PWBs and service manuals. The alphabetical character following LF shows the type of lead-free solder.
Example:
Indicates lead-free solder of tin, silver and copper.
2. Using lead-free wire solder
When fi xing the PWB soldered with the lead-free solder, apply lead-free wire solder. Repairing with conven-
tional 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 40ºC, we recom-
mend you to use a dedicated soldering bit, if you are not familiar with how to obtain lead-free wire solder or
sodening bit, contact our service station or service ranch in your area.
3. 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
turn 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, fi le it with steel wool or fi ne sandpaper.
Lead-free wire solder for servicing
Be careful when replacing parts with polarity indication on the PWB silk.
L F a
Pb
Part No.
Ë
Description Code
ZHNDAi123250E J
φ
0.3mm 250g(1roll)
BL
ZHNDAi126500E J
φ
0.6mm 500g(1roll)
BK
ZHNDAi12801KE J
φ
1.0mm 1kg(1roll)
BM