Panasonic TX-LR42U20 Service Manual ▷ View online
TX-LR42U20
25
7.12. Pedestal Assembly 1
1. Fix stand mtg spacer at pedestal cover.
2. Stick felt at front base plate.
3. Fix base plate at stand mtg and pedestal cover and screw.
4. Stick rubber foot at rotation plate.
5. Apply grease at rotation plate and bush (pede).
6. Fix rotation plate and bush (pede) at base plate and screw.
2. Stick felt at front base plate.
3. Fix base plate at stand mtg and pedestal cover and screw.
4. Stick rubber foot at rotation plate.
5. Apply grease at rotation plate and bush (pede).
6. Fix rotation plate and bush (pede) at base plate and screw.
TX-LR42U20
26
Put Pedestal Assembly into polybag and fold properly
7.13. Pedestal Assembly 2
1. Lay down the unit so that the rear cover faces upward.
2. Remove the 4 screws.
3. Remove the pedestal.
2. Remove the 4 screws.
3. Remove the pedestal.
7.14. Rear cover
1. Remove the 15 screws (A).
2. Remove the 2 screws (B),
3. Remove the rear cover.
2. Remove the 2 screws (B),
3. Remove the rear cover.
TX-LR42U20
27
8 Measurements and Adjustments
8.1.
Voltage chart of A-board
Set A-Board to a dummy set and check the satisfaction with the specified voltage as following table.
8.2.
Voltage chart of P-board
Set IP-Board to a dummy set and check the satisfaction with the specified voltage as following table.
Power Supply Name
Measurement Point
Specification (V)
SUB1.8V
TP5601
1.74 - 1.90
SUB1.2V
TP5600
1.18 - 1.32
SUB3.3V
TP5602
3.19 - 3.46
SUB5V
TP5200
4.9 - 5.1
SUB9V
TP5220
8.82 - 9.18
STB5V
TP5400
4.9 - 5.1
Power Supply Name
Measurement Point
Normal Condition
Stby Condition (V)
P24V
TP7503
24 ± 1.2 V
NO CARE
17V
TP7502
18 ± 2 V
NO CARE
DTV12V
TP7501
12 ± 0.6 V
NO CARE
TUNER6V
TP7601
6.1 ± 0.3 V
NO CARE
DC390V
TP7201
390 ± 10 V
NO CARE
* HOT
TX-LR42U20
28
9 Block Diagram
9.1.
Main Block Diagram
(L
E
D
:7
T
IM
E
S
)
(L
ED
:1
TIM
ES
)
(L
E
D
:4
T
IM
E
S
)
(L
ED
:3
TIM
ES
)
(L
E
D
:9
T
IM
E
S
)
(L
ED
:3
TIM
ES
)
STB5V
TMDS DATA
DCDC
V10
STB_RESET
TUNER5V
INV_SOS
OVP_DET
ERROR DET
TUNER5V
(SIDE)
POWER LED(R)
DTV12V
POWER CONTROL
LCD PANEL
TUNER6V
STB3.3V
INV_SOS
STB5.8V
DCDC
D/A
RECTIFIER
+5.8VS
SUB5V
PANEL POWER SOS
VOFF2-6V
SUB9V
(SIDE)
DCDC
V
SUB9V
SOUND SOS
STB_RESET
DVDD2.5V
AMP
DCDC
SOUND SOS
STB3.3V
VCON31V
INV_ON
(STM)
(SIDE)
DTV_L/R
DROP
D/A CONVERTOR
SUB1.2V
STB5V
CONTROL PANEL
DVB_CVBS
R
L/R
HDMI I/F
PFC CONTROL
V-BOARD
ANALOG-ASIC
Y/PB/PR, R/G/B/H/V CVBS
VOLTAGE
HDMI3
V/Y/PB/PR
STANDBY VOLTAGE RECTIFIER
C.A.T.S. SENSOR
V
DTV12V SENSE
INV_ON
SUB3.3V
PANEL POWER SOS
OPTICAL AUDIO OUT
DCDC
DVDD2.5V
OVP_DET
DCDC
DTV12V
INVERTER POWER CONTROL
CURCUIT
PWM
SUB1.8V
VIDEO PROCESSOR
STB+3.3V
SUB5V
R/G/B/H/V
PWM
VREF_1-12
REMOTE RECEIVER
OVER
AC CORD
STB+3.3V
12V
SUB 3.3V SENSE
AUDIO
PANEL
EEPROM
AUDIO PROCESSOR
SUB_ON
TS Parallel
SD CARD DATA
OPERATION BUTTON
VOLTAGE
K-BOARD
HDMI2
A02
EEPROM
K01
NAND FLASH
DVDD2.5V
ON
HDMI1
LIVE
+5.8VS
INV_PWM
TMDS DATA
POWER LED
INV_PWM
INV_SOS
SUB1.8V
SPEAKER(R)
(A Chip)
AV2
CPU BUS I/F
(D Chip)
CONTROL
DCDC
NEUTRAL
17V
SOS DET
A-BOARD
PANEL
OPTICAL OUT
SUB_ON
SOS DET
AV SW
AVDD13.7V
PC
MONITOR L,R
POWER LED
P-BOARD
POWER SUPPLY
MONITOR OUT
MONITOR V
DIGITAL SIGNAL PROCESSOR
OPTICAL
V
REMOTE RECEIVER
A/D CONVERTOR
AVDD13.7V
P5,P6.P7,P8
C.A.T.S. SENSOR
AVDD13.7V
RECTIFIER
LINE FILTER
SOUND17V
AUDIO
A14
SPEAKER(L)
HP
AV3
HEADPHONE
CPU BUS
INV_PWM
SD CARD
OUT
AV1
SUB ON/OFF
L
+5.8VS
RECEIVER
L/R
HOT START
(DAC_ENB)
SD CARD DATA
TMDS DATA
PROCESS VOLTAGE RECTIFIER
REMOTE IN
L/R
RELAY
32V
DTV12V
Peaks sLD
SOUND17V
TS Parallel
SIF
SUB5V
STB+5.8V
SLOT
SUB3.3V
LVDS DATA
POWER SW
P2
L/R
P1
BACK LIGHT
DCDC
SUB1.2V
A10
LVDS DATA
INV_ON
STB5V
KEYSCAN
A09
A12
C.A.T.S. SENSOR
IFD_OUT
OFDM
SIF_OUT
TUNER
V
USB
USB DATA
(LED:7TIMES)
(LED:1TIMES)
(LED:4TIMES)
(LED:3TIMES)
(LED:9TIMES)
(LED:3TIMES)
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