Panasonic KX-TG8421EB, Service Manual

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KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E
1 Safety Precautions
1.1. For Service Technicians
• Repair service shall be provided in accordance with repair technology information such as service manual so as to pre-
vent fires, injury or electric shock, which can be caused by improper repair work
.
1. When repair services are provided, neither the products nor their parts or members shall be remodeled.
2. If a lead wire assembly is supplied as a repair part, the lead wire assembly shall be replaced.
3. FASTON terminals shall be plugged straight in and unplugged straight out.
• ICs and LSIs are vulnerable to static electricity.
When repairing, the following precautions will help prevent recurring malfunctions.
1. Cover plastic parts boxes with aluminum foil.
2. Ground the soldering irons.
3. Use a conductive mat on worktable.
4. Do not grasp IC or LSI pins with bare fingers.
2 Warning
2.1. Battery Caution
1. Danger of explosion if battery is incorrectly replaced.
2. Replace only with the same or equivalent type recommended by the manufacturer.
3. Dispose of used batteries according to the manufacture’s Instructions.
2.2. About Lead Free Solder (Pbf: Pb free)
Note:
In the information below, Pb, the symbol for lead in the periodic table of elements, will refer to standard solder or solder that con-
tains lead.
We will use PbF solder when discussing the lead free solder used in our manufacturing process which is made from Tin (Sn),
Silver (Ag), and Copper (Cu).
This model, and others like it, manufactured using lead free solder will have PbF stamped on the PCB. For service and repair
work we suggest using the same type of solder.
Caution
• PbF solder has a melting point that is 50
°
F ~ 70
°
F (30
°
C ~ 40
°
C) higher than Pb solder. Please use a soldering iron with
temperature control and adjust it to 700
°
F ± 20
°
F (370
°
C ± 10
°
C).
• Exercise care while using higher temperature soldering irons.:
Do not heat the PCB for too long time in order to prevent solder splash or damage to the PCB.
• PbF solder will tend to splash if it is heated much higher than its melting point, approximately 1100
°
F (600
°
C).
• When applying PbF solder to double layered boards, please check the component side for excess which may flow onto the
opposite side (See the figure below).