LG 47LV4400 Diagram

Note: If a particular area is exhibiting a dimmer backlight level than other areas or the overall brightness seems dim, be
sure to first check the customer's Menu setting for Backlights. Raise the percentage and see if the overall brightness
returns to normal. If not, Check the P-DIM level, it should rise with the percentage shown on screen.
100% = 3.3V. Follow the P-DIM signal all the way to the SMPS.
You can also test each of the 16 blocks functionality by grounding the return path signal (using 220Ω resistor).
LED SINGLE BLOCK TEST (DIM OR DARK PICTURE AREA):
Turn the Brightness, Contrast and Backlights all the way up.
Confirm 50V on C700 +.
Confirm P-DIM is approx. 3V. Using a 220Ω resistor, jump any of
the blocks grounding pin on LCN1 or LCN2 while observing the
picture and each block should turn on maximum.
LCN1 White Plug "SMPS Board" To "Panel LEDs"
Pin Label Run Diode Check
1 VLED 50V OL
2 n/c n/c OL
3 R8 *0.86V~11.67V OL
D800B
4 R7 *0.86V~11.67V OL
398V
5 R6 *0.86V~11.67V OL
6 R5 *0.86V~11.67V OL
113V
7 R4 *0.86V~11.67V OL
8 R3 *0.86V~11.67V OL
9 R2 *0.86V~11.67V OL
10 R1 *0.86V~11.67V OL
11 n/c n/c OL
12 VLED 50V OL
*White to Black screen
HS1
LCN2 Black Plug "SMPS Board" To "Panel LEDs"
Pin Label Run Diode Check
1 VLED 50V OL
2 n/c n/c OL
F1
3 L1 *0.86V~11.67V OL 5A/250V
4 L2 *0.86V~11.67V OL
5 L3 *0.86V~11.67V OL
6 L4 *0.86V~11.67V OL
7 n/c n/c OL
8 L5 *0.86V~11.67V OL
9 L6 *0.86V~11.67V OL
10 L7 *0.86V~11.67V OL
11 L8 *0.86V~11.67V OL
12 n/c n/c OL
13 VLED 50V OL
*White to Black screen
CN202
Test 1
1) Disconnect Main Board.
2) Using 10K resistor, jump 5V_ST
(pin 1) to PWR_ON (pin 10).
3) Apply AC power.
Check 12V (pins 8-9).
10KΩ Check BL power (40V).
No Backlights at this time.
Test 2
CN202
1) Remove AC Power.
2) Leave pin 1 to pin 10 connected.
3) Using 10K resistor, jump 5V_ST
(pin 2) to BL_On (pin 11).
4) Apply AC power.
Check BL power (50V).
10KΩ
Check BLs come on.
(Backlights On).
47LV4400 INTERCONNECT DIAGRAM
LED Drive Signal 50 IRE
Off
On
7.51V p/p 2.5mSec
HGnd
PFC
6.23V
R804A
101V
C800B
HGnd
0V
Q800
HGnd 20.6V
HS3 PC601
307V 21.24V
398V
Q600
170V
L801
398V
165V
Q601
3.54V
165V Hot
D800A
HGnd
Ground
T601
Hot Ground
112V
Reference
R915
Bridge
398V 398V 25V
C961 C958
Do not
Measure
PC901
IC901
HGnd 3.89V
3.38V 4.91V
Gnd
19.45V
5V_ST
1.2V
19.6V
Outside legs
PC903
Hot
Ground
N L
Chassis Ground
CN101
AC
DC Voltages to the Panel
developed by on the Main Board,
Output from TCN1
VCC pins 35, 36 from TL1
Made by TU1 pins 35, 26 (3.3V)
H_VDD pins 38, 29 from TL4
Made by TU1 pin 8 (7.88V)
VDD pins 40, 41 from TP12
Made by TU1 pin 18 (16.47V)
VST pin 47 from TU3 pin 15
(-4.93V)
VGL_I pin 48 from TTP 14
Made by diode TD3 (-5V)
VGH_EVEN pin 49 from TU3
Note; If there is a problem with a load from
Pin 13
Made by TU3 pin 13 (-5V to 26V)
the panel backlights, you can remove AC and
Toggles every second
Disconnect either LCN1 or LCN2. When AC
is reapplied, the Backlight LEDs should turn VGH_ODD pin 50 from TU3
Pin 12
on for about 2 seconds and then they turn off.
Made by TU3 pin 12 (-5V to 26V)
Toggles every second
VGH_R pin 52 from TU3
Pin 10
Made by TU3 pin 12 (-5V to 26V)
Toggles every second
Video (LRLVRO-2+/-) pins 28-33
Video Clock (LMCLK+/-) 26, 27
To the Panel
Video Signal Levels: p/p: Approx: 740mV
PANEL p/n: COV31311201
(1)
PWM Pins 12~14 can vary according to incoming
video IRE level, OSD Backlight setting and then
Intelligent Sensor (room light condition).
Output from the Microprocessor.
Range 0.69V to 3.3V.
To the Panel Backlights PWR-ON: Starts 12V
and 40V LED Power.
No Backlights.
BL-ON: Starts
Backlights
LCN2 LCN1 LED Power goes to
50.
HS5
Backlight Driver Section
50V BL_PWR
100V
C701C
220uF
Outside legs
Gnd
50V
BL_PWR
C700
D700
J28
BL_On/Off
25V
Outside legs
Gnd
D120
C120A
5V_ST
J9
5V_ST CN202
D950
HS4
Gnd
ZD301
12V
To Ft. IR
DC Voltages to the Panel
developed by on the Main Board,
Output from TCN2
VCC pins 25, 26 from TL1
Made by TU1 pins 35, 26 (3.3V)
H_VDD pins 22, 23 from TL4
Made by TU1 pin 8 (7.88V)
VDD pins 20, 21 from TP12
Made by TU1 pin 18 (16.47V)
VST pin 14 from TU3 pin 15
(-4.93V)
VGL_I pin 13 from TTP 14
Made by diode TD3 (-5V)
VGH_EVEN pin 12 from TU3
Pin 13
Made by TU3 pin 13 (-5V to 26V)
Toggles every second
VGH_ODD pin 11 from TU3
Pin 12
J14 "MAIN Board" to "IR Board" to J1
Made by TU3 pin 12 (-5V to 26V)
Toggles every second
VGH_R pin 52 from TU3
Pin 9
Made by TU3 pin 12 (-5V to 26V)
Toggles every second
Video (RMLVO-2+/-) pins 28-33
Video Clock (RMCLK+/-) 34, 35
CN202 "SMPS Board" To CN4 "MAIN Board"
Pin Label STBY Run No Load Diode Check
(1)
14 P-DIM3 0V 0.69V~3.3V 3.36V OL
13 (1) P-DIM2 0V 0.72V~3.3V 3.36V OL
12 (1) P-DIM1 0V 0.69V~3.3V 3.36V OL
11 BL-ON/OFF 0V 3.27V 0V (4.77V) OL
10 PWR_ON 0V 3.27V 4.77V OL
8-9 12V 0V 12.81V 12.87V 1.64V
4-7 Gnd Gnd Gnd Gnd Gnd
1-3 +5VSB 5.24V 5.22V 5.24V OL
Test1 Test2
TL1
TL3
Panel_PWR
Panel_
Gama
TU1
TU2
TL4 E
TQ21
C C
B
B
C
C
E
TL6
1
LVDS_VDD
TQ20
TU3
Level
Q46
Shifter TU14
TCN1 E
C
B
TQ22
TU13
VO
70 Grayed out
U52
components
are on the DDVR
1 TFT_
back side. A V
d O
Driver
j
U48
TCN2
U14
DDR
70
Video/Micro
MEDIATEK
Processor
J14
ARM
MT5376JFMU
Q27
E
C
U15
Y1
B
C
E Q17
B U18
C E
B
B
E
Q15
Q16 B
C
54MHz
G
Q29 D
S
2
Q41
U4
Q71
B
E
C
S U43
3 2 1
U22 G D
MAIN BOARD
S
D Q72
G Q69
C
Q18 C
C
D11
E B
p/n: COV31310701
E B
A2 A1
Q42
Pin Label STBY Run Diode Check
1 IR 3.96V 3.95V OL
2 IR_LED_POWER 5.24V 5.19V 0.99V
3 Gnd Gnd Gnd Gnd
4 LS_SCL 3.42V 3.37V OL
5 LS_SDA 3.42V 3.37V OL
6 Light_Sensor_Det 3.56V 3.47V OL
7 LED_R 3.62V 3.82V OL
8 LED_B 3.03V 3.86V OL
J4 "MAIN Board" To
CN202 "SMPS Board"
Pin Diode
14
OL
13
OL
For DC voltages for Main board
12
OL
components see pages 2, 3 and 4 of the
Interconnect diagram.
11
OL
10 OL
For LVDS video signal waveforms see
page 5 of the Interconnect diagram.
8-9
1.64V
4-7
Gnd
1-3
OL
6.3V each
pin
To SMPS
To Spk
To SPK
CH
J4
14 pin
J5
CH
F2 F1
12V 5V_ST
L41 L36 L44 L45
B
Q14
C
E
C
U21
Q30
U51 B E
Vol
Q47
C
U9 Q8 Audio Amp
C
B
B E
C
B E E
Vol
L43
DV33
U50
Enter
VCCK
A1
D28 C C
A2 D25
C
D27
A2 A1
U6
C
A2 A1
Home
Q66
B E
Q70
L42
Input
V
3 1 2
I
PWR
F3
3
U8
U46
+5VSB
USB
VBS_Processor
U10
12V in
+5V_Tuner
HDMI 1
C
Q40
U13
U34
E
U32 C
TUNE
E B
R
U30
HDMI 2
TDVW-
H814F(A)
U53 C
Q36
B E
A1 A2
D54
B
C
C C
E
U31 D57
A2 A1
B
Q37
C
E
HDMI 2
Ft. IR/Intelligent Sensor
J1
Front IR
p/n: COV31147501