Panasonic TX-R20LA80 Service Manual ▷ View online
3 About Lead Free Solder (PbF)
Note: Lead is listed as (Pb) in the periodic table of elements.
In the information below, Pb will refer to Lead Solder and PbF will refer to Lead Free Solder.
The Lead Free Solder used in our manufacturing process and discussed below is (Sn+Ag+Cu).
Those are Tin (Sn), Silver (Ag) and Copper (Cu), although other types are available.
In the information below, Pb will refer to Lead Solder and PbF will refer to Lead Free Solder.
The Lead Free Solder used in our manufacturing process and discussed below is (Sn+Ag+Cu).
Those are Tin (Sn), Silver (Ag) and Copper (Cu), although other types are available.
This model uses Pb Free solder in its manufacture due to environmental conservation issues. For service and repair work, we
suggest the use of Pb free solder as well, although Pb solder may be used.
PCBs manufactured using lead free solder will have the PbF within a leaf Symbol
suggest the use of Pb free solder as well, although Pb solder may be used.
PCBs manufactured using lead free solder will have the PbF within a leaf Symbol
stamped on the back of the PCB.
Caution
• Pb free solder has a higher melting point than standard solder. Typically the melting point is 50 ~ 70 °F (30 ~ 40 °C) higher.
Please use a high temperature soldering iron and set it to 700 ± 20 °F (370 ± 10 °C).
• Pb free solder will tend to splash when heated too high (about 1100 °F or 600 °C).
If you must use Pb solder, please completely remove all of the Pb free solder on the pins or solder area before applying Pb
solder. If this is not practical, be sure to heat the Pb free solder until it melts, before applying Pb solder.
solder. If this is not practical, be sure to heat the Pb free solder until it melts, before applying Pb solder.
• After applying PbF solder to double layered boards, please check the component side for excess solder which may flow onto
the opposite side. (see Fig. 3)
Fig. 3
Suggested Pb free solder
There are several kinds of Pb free solder available for purchase. This product uses Sn+Ag+Cu (tin, silver, copper) solder.
However, Sn+Cu (tin, copper), Sn+Zn+Bi (tin, zinc, bismuth) solder can also be used. (see Fig.4)
However, Sn+Cu (tin, copper), Sn+Zn+Bi (tin, zinc, bismuth) solder can also be used. (see Fig.4)
Fig. 4
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TX-R20LA80
4 Service Hints
4.1. How To Remove The Pedestal Assembly
• Lay the main unit face down. (see Fig. 5)
Fig. 5
• Remove the 4 fixing screws and the pedestal assembly. (see Fig. 6)
Fig. 6
4.2. How To Remove The Backcover
• Remove the 10 fixing screws. (see Fig. 7)
Fig. 7
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TX-R20LA80
5 Chassis Board Layout
Board Name
Function
A-Board
Main Board
A-Board
Tuner
A-Board
AV2 Terminal
Key Control
Key Control
P-Board
Mains Input, Power Switch
P-Board
Power Supply
V-Board
Remote Receiver, LED IR
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TX-R20LA80
6 Setting Inspection
6.1. Voltage Confirmation
Confirm the following voltages:
A board
Normal mode
Test point
Position
Voltage
Description
TP025
C888
5V ± 0.25V
5V
TP024
C891
8.2V ± 0.5V
8V
TP031
R874
30V ± 2V
30V
Standby mode
TP029
C868 +pin
3.3 ± 0.2 V
STBY3.3V
TP030
C864 +pin
1.8 ± 0.15
STBY1.8V
TP025
C888
<2V
5V
P board
Normal mode
TP842
Q843
23.8V ± 1V
24V switched
TP840
Connector P2, pin12
9.8V ± 1
12V
TP3802
IC3802, pin1
15V ± 1V
15V
TP3800
IC3801, pin4
4.3V ± 0.3V
REG2
TP3801
IC3801, pin21
4.5V ± 0.3V
REG3
Standby mode
TP842
Q843
<10V
24V switched
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TX-R20LA80
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