LG 42LV5500 Training Presentation page 86

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,
st
1 : 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 Inverter.
nd
2 : Turn off Local Dimming in the Customers Menu. If the brightness returns to
normal, examine the signals required for Local Dimming.
(SIN, V-SYNC and SCLK).
You can also test each of the 12 blocks functionality by grounding the return
path signal through a 220Ω. See "Forcing on a Block of LEDs on the right.
P202 White Plug "SMPS Board" To "Panel LEDs"
Pin Label TP Run Diode Check
1 LED+ C256+ 45V OL
2 n/c n/c n/c OL
3 VC-3A EL70 *1.2V~10.4V OL
4 VC-3B EL71 *1.2V~10.4V OL
5 VC-3C EL72 *1.2V~10.4V OL
6 VC-3D EL73 *1.2V~10.4V OL
MOSI Pin 5 P832
7 VC-4A EL74 *1.2V~10.4V OL
Local Dimming On
8 VC-4B EL75 *1.2V~10.4V OL
9 VC-4C EL76 *1.2V~10.4V OL
10 VC-4D EL77 *1.2V~10.4V OL
11 n/c n/c n/c OL
12 LED+ C256+ 45V OL
Local Dimming Off
*White to Black screen
P203 Black Plug "SMPS Board" To "Panel LEDs"
Pin Label TP Run Diode Check
1 LED+ C256+ 45V OL
SCLK Pin 3 P832
2 n/c n/a n/c OL
3 VC-1A EL62 *1.2V~10.4V OL
4 VC-1B EL63 *1.2V~10.4V OL
5 VC-1C EL64 *1.2V~10.4V OL
V-SYNC Pin 8 P832
6 VC-1D EL65 *1.2V~10.4V OL
7 n/c n/a n/c OL
8 VC-2A EL66 *1.2V~10.4V OL
9 VC-2B EL67 *1.2V~10.4V OL
10 VC-2C EL68 *1.2V~10.4V OL
11 VC-2D EL69 *1.2V~10.4V OL
12 n/c n/a n/c OL
13 LED+ C256+ 45V OL
*White to Black screen
SMPS TEST 1: Force Power Supply On.
SMPS TEST 1 SMPS TEST 2
P201 P201 Disconnect P502 on Main board.
Top pins on Top pins on
connector connector
(A) Jump pins 9, 10, 11 or 12 (3.5V) to pin 1.
23 24 23 24
are odd numbers. are odd numbers.
Test Voltage Outputs 12V, 24V to Main and
12V 21 22 12V 21 22
36V to the Inverter Section of the SMPS.
12V 19 20 12V 19 20
Remove AC power. Leave the jumper in place.
DRV-ON
12V 17 18 12V 17 18
15 16 15 16 SMPS TEST 2: Force the Backlights On.
B
STBY 3.5V STBY 3.5V
(B) Jump pins 9, 10, 11 or 12 (3.5V) to pin 18
13 14 13 14
9,10,11,12 9,10,11,12
(DRV-ON). Apply AC power, the Backlights
11 12 11 12
should turn on. Note, the LED B+ will now jump
9 10
9 10
to 65V then back down to 45V.
7 8 7 8
A A
5 6 5 6
Note; If there is a problem with a load from the
panel backlights, you can remove AC and
24V 3 4 24V 24V 3 4 24V
Disconnect P202 or P203. When AC is
1 2 24V 1 2 24V
PWR ON
PWR ON reapplied, the Backlight LEDs should turn on
for about 4 seconds and then shut off.
p/n: EBR72671001
Front IR
Ft. IR/Intelligent Sensor
And Soft Touch Key Board
P832 "SMPS" to P1601 "MAIN Board"
Pin Label Run Diode Pin Label
1 VSYNC 0V OL 5 Gnd
2 SDA 3.25V OL 6 L/DIM0_SCLK
3 SCL 3.25V OL 7 n/c
4 SIN 0.18V OL 8 Reverse
No Stand-By voltages
L601
BD101
-
+
Q602
3.57V p/p
Q601
D603
MOSI Pin 5 P832
3.57V p/p
RL101
F100
3.54V p/p
5A / 250V
SK100 3.15A / 250V
Indicates Hot
AC In
3.5V p/p
Ground
W/Washer
Different Size
PANEL TEST
To run the T-CON "Panel Test",
remove the LVDS cables.
Jump 12V to the 12V fuse.
LVDS
Jump VCC 3.3V to pin 44 on CN1.
White, Red, Blue, Green and Black
patterns show on screen.
(11.76V)
(11.76V)
12V
Gnd
(18.3V) HVDD CN2
L3
(3.35V)
L1
L2
Gnd
D6
D7
Gnd
US1
VDD 16.74V
Pin 18
Q11
Q12
(25.9V) 1 D1
2 2
3
D3 3
2 2
1) 28.9V 1
D2
3) Gnd
2) 28.2V
(30V) 2) 1.6V
3) 30.4V
1) 0.6V
VGL_I -5V
CN5
FL1
C102
C101
Pin 52 VGHR 28V Pin 48 VGL_I -5V
Pin 51 VGHF -5V Pin 47 VST -5V
Pin 50 VGHODD 28V Pin 35 VCC 3.3V
Pin 49 VGHEVEN 28V Pin 40,41 P-VDD 16.74V
TO TFT MODULE
42LV5500 INTERCONNECT DIAGRAM
(1) PWM Pin 22 can vary according to
PWR-ON: Starts 12V, 24V
and 35V LED Power. incoming video IRE level, OSD
Run Diode
DRV-ON: Starts Backlights Backlight setting and then Intelligent
Gnd Gnd
LED Power goes to 65 then Sensor (room light condition).
down to 45V. Output from the Video Processor.
0.1V OL
Range 0.2V to 3.3V.
n/c OL
Gnd 1.91V
To the Panel
P203
P202
45V
- -
+ +
C257 C256
VC_3B
D253 VC_2C
VC_3A
Q251
VC_2D
P701
n/c
SMPS BOARD
p/n: EAY62169801
D251
P832
IC102
D252
D255
D256
T101
D261
P201
Chassis
Ground
IC503
T501
Hot Ground
Q102
F501
IC502
F101 1.6A / 250V
Q101
IC501
Stby: 399V Stby: 397V
Run: 398.5V Run: 396.5V
U5
4)
LVDS
5) Gnd 3.31V
6) Gnd 3) 3.3V
7) Gnd 2)
8) Gnd 2.95V
12V
1) 3.3V
Gnd
Gnd Gnd
(11.76V)
CN1
U5
Panel
F1 3A/125V
Test
FL2
(3.32V)
TP 44
VCC 3.3V
Pin 15 Pin 13
VGHEVEN 28V
VST -5V
UC1
U3 U6
Pin 10 VGHR 28V
Pin 11 VGHF -5V
Pin 7-8
VGHODD 28V
Pin 12
P-VDD 16V
CN4
C105 C106
VDD 16.74V
Pin 9 VGHR 28V Pin 13 VGL_I -5V
Pin 10 VGHF -5V Pin 14 VST -5V
Pin 11 VGHODD 28V Pin 25 VCC 3.3V
Pin 12 VGHEVEN 28V Pin 20,21 P-VDD 16.74V
LCD PANEL
TO TFT MODULE
p/n: EAJ61749101
P201 "SMPS Board" To P502 "MAIN Board"
Pin Label STBY Run Diode Check
24 n/c n/c 2.03V
ERROR
n/c
23 n/c n/c OL
22 PWM 0V 0.2V~3.3V OL
(1)
21 12V 0V 12V 0.48V
20 n/c n/c n/c OL
19 12V 0V 12V 0.48V
DRV-ON 0V 3.26V OL
18
17 12V 0V 12V 0.48V
16 V_Sync 0V 0V OL
13-15 Gnd Gnd Gnd Gnd
9-12 3.5V 3.55V 3.53V 2.63V
5-8 Gnd Gnd Gnd Gnd
2-4 24V 0V 24.5V 1.09V
PWR-ON 0V 3.41V 1.15V
1
E E RL_ON Drivers
C C
B B
Q502 Q501
3 2 IC502 Power Det (24V)
Q504
1
3 IC503 Power Det (12V)
2
B 1
P502
C
E
Q1701
INV_CTL
L1704
C
Driver Audio Mute
L1703
E B
IC1702
To Spk
Audio Amp
L1708
P1702
12.2V
L1707
Each Pin
P1502
IC401 DDR
P1501
IC402 DDR
B E
Q505
IC508
C
B +1.5V_DDR
Q506
C E
G S
Q507
+2.5V_BCM35230
D
IC504
EEPROM
P601 N/C
X601
Microprocessor IC601
IC602
P901
Q904
C D
Q1002
Q906
E B C
X602 G S
E
C
B E
C Q1001
B Q901
B E SW1
B
Q902
C
E
RS232
SW1 Microprocessor Reset
IC803
P1302
Warning:
T-CON Board
under shield. IC801 IC802
Be sure to reinsert
C
screws before D810
A1 A2
operating set with
shield removed.
P901 Connector "MAIN Board" To "IR Board"
Pin Label STBY Run Diode Pin Label STBY Run Diode Pin
13
1 7
SCL 2.9V 3.49V 3.28V Gnd Gnd Gnd Gnd
2 8 14
SDA 2.92V 3.49V 3.28V LED_B 0V 0V OL
3 9
Gnd Gnd Gnd Gnd IR 1.48V 1.45V OL 15
4 KEY 1 3.26V 3.28V 1.88V 10 Gnd Gnd Gnd Gnd
5
KEY 2 3.26V 3.28V 1.88V 11 +3.3V_Normal 0.35V 3.34V 0.53V
6
3.5V_ST 3.55V 3.49V 1.15V 12
LED_R 0V 0V 2.67V
P1302 "MAIN Board" To "Motion Remote"
Pin Label STBY Run Diode Check
1 3.5V_Normal 0.35V 3.34V 0.53V
2 Gnd Gnd Gnd Gnd
3 M_Remote_RX 0.35V 3.33V OL
4 M_Remote_TX 0.35V 3.33V OL
5 Reset 0.35V 3.33V 2.41V
6 DC_MRemote 0.35V 3.33V 2.38V
7 DD_MRemote 0.35V 3.33V Gnd
8 Gnd Gnd Gnd Gnd
9 GPI0-O 0V 0V OL
10 GPI0-1 0V 0V OL
11 GPI0-2 0V 0V OL
12 GPI0-3 0V 0V OL
P502
"MAIN Board"
P1601
To P201
"SMPS Board"
P101
N/C Pin
0.9V FET
P102 1
Switch
5V_Normal
N/C 3.3V_
L505
2-4
Q503
IC507
Normal
+0.9V_CORE L516 5-8
IC505
IC501
9-12
IC506
Q508
13-15
L515
0.9V FET
Switch 16
5V_USB
L509
17
18
USB2 EDID
NAND
19
IC1203
FLASH
IC102
20
21
NVRAM
BCM 22
IC103
Q102
IC101
23
G B
RGB_DDC_SCL
IC1204
D S
D G 24
RGB_DDC_SDA
S
B
Q101
CEC P1601
USB1 EDID "SMPS Board" To
Q710
Earphone P832 "MAIN Board"
G B
IC804 IC701
D S
Amp
A1 C Pin
A2
B E
Q801
D713
C
1
MAIN BOARD
2
HDMI
C
3
Selector
A1 A2
p/n: EBR71850702
D711
4
p/n: EBR73146501
5
p/n: EBR71850705
D708 6
Wireless Dongle
A1
C
Switch
A2 7
Grayed out components are on the back
8
18. IF p
18
17. IF n
16. IF AGC
D710
15. Reset
14. 3.3V
C
13. 1.26V B E
Q2105
12. GND 3 1
C A1 A2
TU2101 2
11. CVBS
IC2103
10. NC
B E
Q2104
TUNER 9. SIF
C 2
8. NC +1.26V_TU
7. SDA
6. SCL
A1
5. NC C
4. NC
A2
3. 5V
D707
1
2. NC
1. NC
For DC voltages for
Main board
components see
Label STBY Run Diode Page 2 of the
Interconnect diagram.
Gnd Gnd Gnd Gnd
S/T_SCL 3.55V 3.49V 1.86V
S/T_SDA 3.55V 3.49V 1.86V
p/n: EBR72499601
Motion Remote
Diode
2.89V
OL
Gnd
1.15V
Gnd
OL
2.07V
1.53V
2.07V
OL
2.07V
2.35V
OL
OL
Diode
Gnd
OL
OL
Gnd
OL
1.61V
1.59V
OL