54
25. Power Supply
Chapter 25 - Power Supply
The Standby power supply circuit and power ON sequence is simple and easy to figure out by looking at the
simplified Figure 11-1. The only outstanding servicing precaution you must make note of is the over voltage
zener diode on the A board at CN1901/pin 3 in Figure 25-1. If it shorts, it will load down the standby 5Vdc and the
TV will not respond to a power ON command (dead TV set).
Standby Power Supply
The standby power supply is located on the G board with the main power supply. Standby voltage is output when
the TV is plugged into AC. Standby 7Vdc is output CN1605/pin 4 into the bottom A board where it is regulated
down to 5Vdc and passed onto the Main Micro on the M board (via CN1921/pin 16).
IC9004
MAIN
MICRO
IC1905
REG.
MAIN
POWER
SUPPLY
STANDBY
POWER
SUPPLY
3
1
4
2
5
1
3
1
Q1603
ERROR REG.
1
2
2
6
1
2
3
4
1
2
3
4
3
7
5
47
45
16
48
IR
STBY
5V
STBY
LED
21
POWER
SIRCS
STBY LED
STBY 5V
PWR
ON
POWER
PWR RELAY RY1601
0.2
Ω
0.5
Ω
STBY 5V
F1601 6.3A
R1627
22 1W
PS1601
PS1602
CN 1614
SMP-B28
BI-METAL FUSE
LOCATED
UNDER REAR
FAN
POWER
CONTROL
17V
33V
CN1605/
CN1914
CN1604/ CN1926
5V
+15V
-15V
AUDIO
11V
4.5V
CN1606/ CN1909
CN1613/
CN1914
CN1603/
CN1915
CN1602
R1613
R1654
R1655
270V TO LAMP
DRIVER BD.
CN1616
CN1921/
CN9001
5V=ON
0V=OFF
STBY
7V
R1618
R1617
M BB
BC
TUNERS
A BD.
BOARD LAYOUT
U
G
FIGURE 25-1 - POWER ON BLOCK - KF-60DX100
4.5V
11V
7V
+
-
D1931
5TVP13 1438
4/11/02
A BD.
G BD.
H3 BD.
1
3
M BD.
CN4502/
CN1901
4