LG TRAINING TRAINING MANUAL Fall 2008 LCD Training
32LG40
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Address
Description
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Product information
Customer Service
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User manuals, FAQs
GCSC
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Service manuals, parts, bulletins
Cust Cu stom omer er Se Serv rvice ice Ac Acad adem emyy
www.l www .lgc gcsa saca cadem demyy.c .com om
Web tr trai ainin ning, g, di discu scussi ssion on fo foru rum m
Live Training
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Live training
Published July 2008 by LG Electronics USA Training Center Copyright © 2008 LG Electronics of Alabama, Inc. IMPORTANT SAFETY NOTICE
TABLE OF CONTENTS OVERVIEW OVER VIEW ........ ................. ................. ................. ................. ................ ........ 5
CIRCUIT DESCRIPTIONS DESCRIPTIONS - 42LG 42LG60 60 ........ .......... 45
Introduction ............. ........................... ............................ .........................5 ...........5 Basic Troubleshooting Steps ............................5 Caution..................... Caution....... ............................ ............................ .........................5 ...........5 Model Number Structure ............. ........................... ..................6 ....6 Serial number Structure .................... .................................. ..............6 6 Features .............. ............................ ............................ ............................ ................7 ..7 32LG40 Dimensions............................. ........................................8 ...........8 42LG60 Dimensions............................. ........................................8 ...........8 Remote Control....................................... ..............................................9 .......9 New Features ............ .......................... ............................ .......................9 .........9 Computer Connection............. ........................... .................... ...... 10 Service Menu.............. Menu............................ ............................ .................... ...... 10 Power Consumption ....................... .................................... ............. 10 Service Remote .................... .................................. ........................ .......... 11 Check Firmware Version ..................... ............................. ........ 12 Update Firmware.............. ............................ ........................... ............. 12
Introduction ...................................... ................................................. ........... 45 Backlight Layout .................. ................................ ......................... ........... 46 Power Supply Layout ........................ ................................... ........... 47 Control Board Layout ....................... .................................. ........... 49 LCD Driver (T-CON) Layout ............. ...................... ......... 51 Main board layout ................................. ........................................ ....... 53 Invisible Speaker SyStem Layout .............. .................. .... 61
DISASSEMBLY DISASSEMBL Y - 32LG40 ..................... ............................ ....... 13 Back Cover Removal .............. ............................ ...................... ........ 13 Board Layout.............. ............................ ............................ .................... ...... 13 Power Supply Removal ...................... ................................ .......... 14 Main Board Removal .............. ............................ ...................... ........ 14 LCD Driver Removal ........................... ................................... ........ 15 Ballast Removal ............................... ............................................ ............. 16 DVD Player Removal ........... 17
SCHEMATICS SCHEMA TICS .................... ......................................... ........................ ... 63 32LG40 :: Interconnect............. ........................... ................... ..... 63 32LG40 :: WaveFo WaveForms rms ........................ ................................. ......... 64 32LG40 :: Main Board :: Main Micro ............ 65 32LG40 :: Main Board Board :: Audio .................... .................... 66 32LG40 :: Main Board :: Memory .............. ................ .. 67 32LG40 :: Main Board :: BCM/USB..... BCM/USB ......... ......... ..... 68 32LG40 :: Main Board :: DCM ................ ..................... ..... 69 32LG40 :: Main Board :: LVDS/DVD............ 70 32LG40 :: Main Board :: Tuner Tuner Power ......... ......... 71 32LG40 :: Main Board :: Jackpacks ............. ............... .. 72 32LG40 :: Main Board :: HDMI ............. .................... ....... 73 42LG60 :: Interconnect............. ........................... ................... ..... 74 42LG60 :: Wavefo Waveforms rms ......................... .................................. ......... 75 42LG60 :: Main Board :: BCM.............. ..................... ....... 76 42LG60 :: Main Board :::: DDR Memory Memory ...... 77 42LG60 :::: Main Board :: Main Main Micro 78
OVERVIEW OVERVIEW
2008 LCDS
INTRODUCTION The manual covers two models from the 2008 LCD product line. Each model is an HDTV with integrated HD tuner. The 32LG40 is a 720p/1080i model, the 42LG60 supports 1080p (Full HD). All models 32” and larger include USB Media Host and SimpLink. USB Media Host consists of a USB port on the back of the TV that supports USB flash memory drives loaded with media or firmware for the TV. SimpLink allows for control of other LG SimpLink products via the HDMI connection. All LCD TV models are module level repair in and out of warranty. They are covered by a one year parts and labor warranty. Refer to the last page of the owner’s manual for more warranty information. For models under 30”, the Sevice Level is Factory Service Repair. Larger models are Field Service. Contact the Warranty department for more information.
BASIC TROUBLESHOOTING STEPS Define - Look at the symptom carefully and determine what circuits could be causing the failure. Use your senses Sight, Smell, Touch and Hearing. Look for burned parts and check for possible overheated components. Capacitors will sometimes leak dielectric
OVERVIEW 3) Be cautious of electric shock from the Backlight section, it uses high voltage AC. Check that the Power Supply and Drive Circuits are completely discharged because of residual current stored before circuit board removal. 4) C-MOS circuits are sensitive to static electricity. Use caution when dealing with these IC and circuits. 5) Exercise care when making voltage and waveform checks to prevent costly short circuits from damaging the unit. 6) Be cautious of lost screws and other metal objects to prevent a possible short in the circuitry. 7) Check the appearance of the Replacement Panel and Circuit boards for both physical damage and part number accuracy. Verify model names and board model matches.
MODEL NUMBER STRUCTURE
Region U = North America B = Europe & NA
42LG60-UA
OVERVIEW FEATURES
32LG40
Model Name
42LG60
32LG40
47LG60
LP81A
LP81A
1366 x 768p
1920 x 1080p
500
500
Contrast Ratio (Bare Module)
1,200:1
1,500:1
Dynamic Contrast Ratio
10,000:1
12,000:1
Vi
178/178
178/178
Chassis Name Screen Specs Resolution Brightness (cd/m2)
i
A
l
OVERVIEW 32LG40 DIMENSIONS 31.8" 808mm
4.3" 109mm
7.9" 200mm
12" 304.8mm
3.9" 100mm
8.38" 212.74mm
3.9" 100mm
Not Center Center
24.8" 629.92mm 21.7" 551.2mm
11" 279mm
Model No. Serial No. Side Label
9 11/16" 246.06mm
Remove 4 screws to remove stand for wall mount
3.5" 89mm
OVERVIEW REMOTE CONTROL 2008 models feature a newly designed, easier to use remote. The remote has fewer buttons than previous designs which was accomplished by moving many functions to an on-screen Quick Menu. The “Q. MENU” button on the remote opens the Quick Menu and the user can choose between options like aspect ratio, closed captions, sleep timer, etc. The remotes are programmable for other devices. These LCDs also support SimpLink devices. When using SimpLink, the device buttons on the remote do not need to be pressed to switch modes before controlling external equipment. External devices are controlled by the TV instead of the remote.
TV
POWER
DVD
MENU
INPUT
VCR
STB
Q. MENU
ENTER
RETURN
AV MODE
FAV
NEW FEATURES Below are some of the new features on some 2008 LCD TVs. Intelligent sensor - LG’s “Intelligent Sensor” uses 4,096 sensing steps to evaluate its surroundings. Using a sophisticated algorithm, the LG processes picture quality elements including brightness, contrast, color, sharpness and white balance. The result is a picture optimized
CH
VOL
MUTE
1
2
3
4
5
6
P A G E
OVERVIEW COMPUTER CONNECTION A computer can be connected to the RGB (VGA) or HDMI connection on the TV. The HDMI connection will require a DVI to HDMI adapter if the PC has a DVI connector. Set the monitor output resolution and vertical frequency on the PC before connecting it to the TV. Refer to the owner’s manual for a full list of suported resolutions. The message “OUT OF RANGE” will appear on the screen if the resoultion is not supported. Resolution
Vertical Frequency (Hz)
30/40/50/60/70 series 1280x768
60Hz
1360x768
60Hz
1366x768
60Hz
POWER CONSUMPTION Model
On TYP
MAX UNIT
Stand-By TYP
MAX UNIT
19LS4D-UA
42W
0.85
1W
20LS7D-NB
56W
0.85
1W
20LS7D-UK
56W
0.85
1W
22LC2D-UB
46W
0.85
1W
22LS4D-UA
46W
0.85
1W
23LS7D-NB
78W
0.85
1W
23LS7D-UK
78W
0.85
1W
26LC7DC-UB
110 160W
0.7
1W
26LC7DC-UK
30 160W
0.7
1W
26LC7D-UK
30 160W
0.7
1W
26LG30DC-UA
99 115W
0.36
0.8W
150 190W
0.7
1W
32LC4D-UA 32LC50C-UA
190W
3W
32LC5DC-UA
190W
3W
32LC7DC-UK
170 190W
0.7
1W
32LC7D UB
150 190W
07
1W
OVERVIEW SERVICE REMOTE NUM KEY
FUNCTION
1
POWER
To turn the TV on or off
2
POWER ON
To turn the TV on automatically if the power is supplied to the TV. Use the POWER key to deactivate; It should be deactivated when delivered.
3
MUTE
To activate the mute function.
4
P-CHECK
To check TV screen image easily.
5
S-CHECK
To check TV screen sound easily
6
ARC
To select size of the main screen (Normal, Spectacle, Wide or Zoom)
7
CAPTION
Switch to closed caption broadcasting
8
TXT
To toggle on/off the teletext mode
9
TV/AV
To select an external input for the TV screen
10
TURBO SOUND
To start turbo sound
11
TURBO PICTURE
To start turbo picture
12
IN-START
To enter adjustment mode when manufacturing the TV sets. To adjust the screen voltage (automatic): In-start mute Adjust AV (Enter into W/B adjustment mode). W/B adjustment (automatic): After adjusting the screen W/B adjustment Exit two times
13
ADJ
To enter into the adjus tment mode. To adjus t hori zontal lin e and sub-bri ghtness.
14
MPX
To select the multiple sound mode (Mono, Stereo or Foreign language).
15
EXIT
To release the adjustment mode.
16
A PC( PS M)
To ea si ly ad ju st th e s cre en ac co rd in g t o s ur ro un di ng br ig ht ne ss .
17
ASC(SSM)
To easily adjust sound ac cording to the program type.
18
MULTIMIDIA
To check component input.
19
FRONT-AV
To check the front AV.
20
CH
To move channel up/down or to select a function displayed on the screen.
OVERVIEW CHECK FIRMWARE VERSION You can check the firmware version by opening the service menu. It is located near the top of the menu.
UPDATE FIRMWARE
LP81A LPL L42FHD Main V1.62 USB V2.14 00 HDCP 0 UTT 97 Tool Option1 39848 Tool Option 2 51 Ar ea Optio n 1 OPTION1 43 OPTION2 46 OPTION3 0 OPTION4 0 System Control Audi o Pr escale Threshold Power Off Histor y Panel Control Davinci / Auto Test
1) Copy the firmware to the top level on a USB flash drive and to a folder named LG_DTV. Some models require the LG_DTV folder, and some don’t. Put it in both locations if you are not sure which is correct. Only copy the file (or files) for the model you are currently updating. 2) Turn on the TV and insert the USB drive to the USB IN port. 3) If the firmware is newer than what is already installed, the upgrade menu should open
DISASSEMBLY DISASSEMBLY
32LG40
BACK COVER REMOVAL Remove the 18 screws shown. Pay attention to the size and type of screw as there are many different types. Putting in the improper screw when reassembling may cause damage. The stand does not need to be removed.
3 2 L G 4 0
DISASSEMBLY
3 2 POWER SUPPLY REMOVAL P203, P201, and AC In. Now L Disconnect remove the 4 screws indicated. G 4 0
DISASSEMBLY LCD DRIVER REMOVAL Remove the screws and then the brace.
Remove Screw Remove Screw
3 2 L G 4 0
DISASSEMBLY BALLAST REMOVAL
3 2 L G 4 0
Remove the shield and then the ballast. Be sure all heat sinks and insulators are in place when re-assembling. S h i e l d
Heat Transf er Material
Protects the Outputs Al ig nm ent Notch Insulator Shiny Side Down
DISASSEMBLY DVD PLAYER REMOVAL Remove the tape and then remove the 8 screws holding the DVD Player in place.
Remove Tape
3 2 L G 4 0
DISASSEMBLY EXPLODED VIEW
40 0
20 0
3 2 L G 4 0
80 0 80 2
30 0
80 5 80 4
51 0
12 0
80 3
12 1 80 1
80 6 12 2 12 3
52 1 82 1
50 0 91 0
54 0
82 0 53 0
82 2 53 1
90 0
CIRCUIT DESCRIPTIONS CIRCUIT DESCRIPTIONS
32LG40
POWER SUPPLY (SMPS) P203 To Ballast 1
1
P201 To Main
No Connection
F100 5A/250V
F101 3.15A/250V 250V
3 2 L G 4 0
CIRCUIT DESCRIPTIONS POWER SUPPLY CONNECTORS P201 “SMPS” to P800 “Main”
3 2 L G 4 0
Pin Label
Stby
Run Diode Check
Pin
Label
Stby
Run Diode Check
23
N/C
0V
3.2V
OL
24
N/C
0V
0V
OL
21
BR1
0V
1.68V
OL
22
PWM-DIM
0V
3.38V
OL
19
PWR
0V
2.86V
OL
20 INV On/Off
0V
3.29V
OL
17
ERR
0V
3.3V
1.26V
18
ACD
5.05V 4.57V
OL
15
Gnd
Gnd
Gnd
Gnd
16
Gnd
Gnd
Gnd
Gnd
13
Gnd
Gnd
Gnd
Gnd
14
Gnd
Gnd
Gnd
Gnd
11
5.2V
5.15V 5.15V
0.34V
12
5.2V
5.15V 5.15V
0.34V
9
5.2V
5.15V 5.15V
0.34V
10
5.2V
5.15V 5.15V
0.34V
7
Gnd
Gnd
Gnd
Gnd
8
Gnd
Gnd
Gnd
0V
5
12V
0V
11.8V
1.69V
6
12V
0V
11.8V
1.69V
3
Gnd
Gnd
Gnd
Gnd
4
Gnd
Gnd
Gnd
Gnd
1
16 5V
0V
16V
0 31V
2
16 5V
0V
16V
0 31V
CIRCUIT DESCRIPTIONS POWER SUPPLY TEST 24 22 20 18 16 14 12 10 8 6 4 2 The Power Supply must be producing P2 STAND-BY +5V before performing this 23 21 19 17 15 13 11 9 7 5 3 1 PWR +5V test. With the Power Supply disconnected from other boards and AC applied, confirm 10K that the Power Supply is producing 5V from either Pins 9, 10, 11 or 12. If not, check the fuse. If the fuse is ok and there is no 5V, replace the Power Supply. If 5V is ok, continue. 1st short either pin 9, 10, 11 or 12 (5V) to pin 19 (PWR) using a 10K resistor. The P201 connector should be disconnected from the Main board and AC not applied when adding the jumper. Re-apply power when testing. Confirm that the other low voltage power supplies are activated. Pins 1 and 2: 16V Pins 5 and 6: 12V Pin 18: AC Detect goes high Fuse F101: Check for 350V (Ballast Voltage) If any voltage missing, replace the Power Supply. If the 1st test was successful, leave the
3 2 L G 4 0
CIRCUIT DESCRIPTIONS MAIN (DIGITAL) BOARD
3 2 L G 4 0
CIRCUIT DESCRIPTIONS IC806
D3.3V/A3.3V_BCM Regulator turn s on LD800
Q801
5V SUB SWITCH
PIN
FUNCTION
NAME
STBY
RUN
PIN
FUNCTION
NAME
STBY
RUN
1
On/Off Control
Power_CTL_3.3V
0V
3.4V
1,3
IN
ST_5V
0V
5V
2
IN
+5V_SUB
0.36V
5V
2,4
On/Off Control
Q802
0V
0.28V
3
Gnd
Gnd
Gnd
Gnd
5,6,7,8
OUT
+5V_SUB
0V
5V
4
OUT
D3.3V_BCM
0.1V
3.4V
Q802
IC807
D3.3V/A3.3V_BCM Regulator
5V SUB SWITCH CONTROLLER fo r Q801
PIN
FUNCTION
NAME
STBY
RUN
PIN
FUNCTION
NAME
STBY
RUN
B
On/Off Control
RL_ON
0V
3.29V
1
IN
+9V
0V
8.9V
C
Pull Down
ST_5V
0V
5V
2
On/Off Control
Power_CTL_3.3V
0V
3.4V
E
Gnd
Gnd
Gnd
Gnd
3
OUT
+5V
0V
5V
Q400
4
n/c
n/c
n/c
n/c
PIN
FUNCTION
NAME
STBY
RUN
5
Gnd
Gnd
Gnd
Gnd
B
Reset
Reset
0.6V
0.6V
C
Vcc
3.3VVST_MICON
0V
0V
E
Gnd
Gnd
Gnd
Gnd
IC809
D2.6V/A2.6V_BCM Regulator
PIN
FUNCTION
NAME
STBY
RUN
6,7,8,10
IN
+5V_SUB
0.36V
4.98V
17
On/Off Control
Power_CTL_2.6V
0V
3.41V
1,2,3,4,5
OUT
D2.6V_BCM
0V
2.66V
14,15
n/c
n/c
n/c
n/c
11,18,19,20
Gnd
Gnd
Gnd
Gnd
RESET GENERATOR FOR MICRO IC407
3 2 L G 4 0
CIRCUIT DESCRIPTIONS IC401
3 2 L G 4 0
BCM RESET
IC808
ST-BY 3.3V DC-DC CONVERTER
PIN
FUNCTION
NAME
STBY
RUN
PIN
FUNCTION
NAME
STBY
RUN
14
IN
D3.3V_BCM
0V
3.41V
2
IN
ST_5V
5V
5V
1
On/Off Control
Reset from IC400
0V
3.4V
3
OUT
3.3VST_MICON
3.43V
3.43V
6
OUT
BCM_RESET
0V
3.4V
4
Gnd
Gnd
Gnd
Gnd
IC801
+1.8V_NTP REGULATOR
Q900
LVDS 12V SWITCH CONTROLLER Q901
PIN
FUNCTION
NAME
STBY
RUN
PIN
FUNCTION
NAME
STBY
RUN
1
Gnd
Gnd
Gnd
Gnd
B
Control
LVDS_PANEL_CTRL
0V
0.75V
2
OUT
'+1.8V_NTP
0V
1.8V
C
Pull Down 12V
LVDS Switch Control
0V
0V
3
IN
3.3V_TMDS_SW
0.26V
3.29V
E
Gnd
Gnd
0V
0V
IC805
D1.2V/A1.2V BCM REGULATOR
Q901
LVDS 12V SWITCH
PIN
FUNCTION
NAME
STBY
RUN
PIN
FUNCTION
NAME
STBY
RUN
6,7,8,10
IN
+5V_SUB
0.38V
5V
1,3
IN
12V
0V
12.36V
17
On/Off Control
Power_CTL_1.2V
0V
3.41V
2,4
On/Off Control
Q900
0V
6.16V
1,2,3,4,5
OUT
D1.2V_BCM
0V
1.29V
5,6,7,8
OUT
LVDS 12V
0V
12.36V
13, 14,15,16
n/c
n/c
0V
0V
11,12,18, 19,20
Gnd
Gnd
Gnd
Gnd
Screen Print for Pin No is incorrect, use IC
MAIN BOARD X400 AND X200 CHECK
CIRCUIT DESCRIPTIONS TUNER VIDEO AND SIF OUTPUT CHECK For Easy Access, pop the shield off the tuner. If you leave the shield on you can still access the same pins. Be careful not to accidentally ground out you test lead on the shield.
Pin 16 Composite Video Pin 14 Audio SIF
Pin 3 Tuner B+ (5V)
3 2 L G 4 0
CIRCUIT DESCRIPTIONS
3 2 L G 4 0
MAIN LVDS CHECK To confirm that the Main board is outputting Picture Content signals, check P902 (LVDS) for output. Check pins 11-20. This signals vary, but looking for signals like the ones shown below on any of these pins will confirm the output of video content. This signal is using a standard SMTE Color Bar output from a generator as the input source. Remember there are actually 10 pins with LVDS signals. This only represents two waveforms as an example.
P902 Location
MAIN PWB
Pin 11
CIRCUIT DESCRIPTIONS MAIN VOLTAGES P800 “Main” to P201 “SMPS”
P401 “MAIN” to “Front Keys”
Pin
Label
Stby
Run
Diode Check
Pin
Label
Stby
Run
Diode Check
1, 2
16V
0V
16V
OL
1
KEY3
3.4V
3.4V
1.4V
3, 4
Gnd
Gnd
Gnd
Gnd
2
KEY4
3.4V
3.4V
1.4V
5, 6
12V
0V
11.8V
3.03V
3
Gnd
0V
0V
Gnd
7, 8
Gnd
Gnd
Gnd
Gnd
4
Gnd
0V
0V
Gnd
9, 10
ST-5V
5V
5.15V
1.23V
5
KEY-1
3.4V
3.4V
1.4V
11, 12
ST-5V
5V
5.15V
1.23V
6
KEY-2
3.4V
3.4V
1.4V
13, 14
Gnd
Gnd
Gnd
Gnd
7
n/c
0V
0V
OL
15, 16
Gnd
Gnd
Gnd
Gnd
8
ST-5V
5V
5V
0.53V
17
VBR-B 5V-MNT
0V
3.3V
OL
9
PWM-LED
0V
0V
0.8V
18
AC-DET
5V
4.57V
OL
10
IR
4.1V
4.1V
2.3V
19
RL-ON
0V
2.86V
1.25V
11
n/c
0V
0V
OL
20
INV-On/Off
0V
3.29V
2.15V
12
Gnd
0V
0V
Gnd
21
BR1
0V
1.68V
OL
13
LED-G
0V
2.1V
0.8V
22
VBR-B
0V
3.38V
2.15V
14
LED-R
2.1V
0V
0.8V
23
n/c
0V
3.2V
OL
15
Gnd
0V
0V
Gnd
3 2 L G 4 0
CIRCUIT DESCRIPTIONS
3 2 L G 4 0
MAIN VOLTAGES For locations, refer to the Main board’s bottom view. The panel control is on pin 33 of IC407. Q900 turns on Q901, the LVDS Switch generats LVDS 12V. All voltages are shown on the Interconnect diagram in the schematics section. LVDS Signal Waveforms are shown on the back of Interconnect diagram.
LVDS 12V
CIRCUIT DESCRIPTIONS
P900 “Main” to P402 “DVD Player” Pin
Label
Stby
Run
Diode Check
1
Disk-Enable
3.4V No Disc 3.4V 0V Disc In
2
DVDP-RXD
0.7V
3.08V
3V
3
DVDP-TXD
0.7V
3.4V
3V
4
Gnd
Gnd
0V
Gnd
1.68V
P901 “Main” to CN400 “DVD Player” Pin
Label
Stby
Run
Diode Check
1
12V
0V
12.3V
3V
2
Gnd
0V
0V
Gnd
3
DVDP 3.3V
3.4V
3.37V
.099V
4
Gnd
0V
0V
Gnd
5
Gnd
0V
0V
Gnd
6
5V
0V
5.01
0.45V
3 2 L G 4 0
CIRCUIT DESCRIPTIONS BALLAST ASSEMBLY
3 2 L G 4 0
Ballast Start Det LED LED1 MCN1 F1 8A/125V
Transformers
To Backlight Left Side To Backlight
CIRCUIT DESCRIPTIONS BALLAST TRANSFORMER WAVEFORMS Warning: secondary is over 1.2Kv.
MCN1 “Ballast” to P203 “SMPS”
34V p/p 64.89kHz
22.2V p/p 220kHz T1/T2 Pin 1
T1/T2 Pin 6
Pin
Label
1
VBL
0V 24.52V
OL
2
VBL
0V 24.52V
OL
3
VBL
0V 24.52V
OL
4
VBL
0V 24.52V
OL
5
VBL
0V 24.52V
OL
6
Gnd
Gnd
Gnd
Gnd
7
Gnd
Gnd
Gnd
Gnd
8
Gnd
Gnd
Gnd
Gnd
9
Gnd
Gnd
Gnd
Gnd
Gnd_1 Gnd
Gnd
Gnd
10
Primary Side
Run
Diode
11 BVR_A
0V
1.67V
OL
12
On/Off
0V
3.45V
OL
13 VBR_B
0V
3.40V
OL
Gnd
Gnd
14
Transformers
Stby
Gnd_2 Gnd
3 2 L G 4 0
CIRCUIT DESCRIPTIONS LCD DRIVER (T-CON)
3 2 L G 4 0
If you test the TV with the shield off of the LCD Driver, reinstall the screws for grounding purposes. Use the Connector P902 on the Main board for Voltages and Signal readings. To TFT Panel
To TFT Panel
CN2
CN3
US2
12V F1 6.3V/1.5A
CIRCUIT DESCRIPTIONS LCD DRIVER VOLTAGES Use P902 on the Main board for making voltage, resistance, and waveform checks. CN1 “LCD Drvier” to P902 “Main” Pin
Label
Stby Run Diode Check
Pin
Label
Stby Run Diode Check
1
LVDS 12V 0V
12.3V
OL
2
LVDS 12V 0V 12.3V
OL
3
LVDS 12V 0V
12.3V
OL
4
LVDS 12V 0V 12.3V
OL
5
Gnd
0V
0V
Gnd
6
Gnd
0V
0V
Gnd
7
Gnd
0V
0V
Gnd
8
Gnd
0V
0V
Gnd
9
Gnd
0V
0V
Gnd
10
Gnd
0V
0V
Gnd
11
LVDS
0V
1.2V
0.98V
12
LVDS
0V
1.1V
0.98V
13
LVDS
0V
1.2V
1.11V
14
LVDS
0V 1.05V
1.06V
15
LVDS
0V
1.1V
1.06V
16
LVDS
0V 1.09V
1.05V
17
LVDS
0V
1.08V
1.11V
18
LVDS
0V 1.13V
1.06V
19
LVDS
0V
1.14V
1.11V
20
LVDS
0V 1.06V
1.06V
21
n/c
0V
n/c
OL
22
n/c
0V
n/c
OL
23
/
0V
/
G d
24
/
0V
/
OL
3 2 L G 4 0
CIRCUIT DESCRIPTIONS DVD PLAYER
3 2 L G 4 0
DVD PLAYER VOLTAGES Resistance should be taken in diode mode with the connectors removed.
CIRCUIT DESCRIPTIONS FRONT BOARD FRONT VIEW
ZD1 5V Zener ZD2 4.1V Zener
J1
J2 To Side Keys PWB
REAR VIEW
ZD3 3.4V Zener
To Main PWB
3 2 L G 4 0
CIRCUIT DESCRIPTIONS FRONT BOARD VOLTAGES Resistance should be taken in diode mode with the connectors removed.
3 2 L G 4 0
J1 “Front board” to P401 “Main”
J2 “Front board” to P101 “Side Key”
Pin
Label
Stby
Run
Diode Check
Pin
Label
Stby
Run
Diode Check
1
KEY3
3.4V
3.4V
OL
1
Key 1
3.4V
3.4V
OL
2
KEY4
3.4V
3.4V
OL
2
Gnd
0V
0V
Gnd
3
Gnd
0V
0V
Gnd
3
4
Gnd
0V
0V
Gnd
4
5
KEY-1
3.4V
3.4V
OL
5
6
KEY-2
3.4V
3.4V
OL
6
7
n/c
0V
0V
OL
7
8
ST-5V
5V
5V
2.7V
8
9
PWM-LED
0V
0V
2.4V
10
IR
4.1V
4.1V
OL
11
n/c
0V
0V
OL
12
Gnd
0V
0V
Gnd
13
LED-G
0V
2.1V
3.2V
LED R
V
0V
V
Key 2 3.41V 3.41V Gnd
0V
0V
Key 3 3.41V 3.41V Gnd
0V
0V
Key 4 3.41V 3.41V Gnd
0V
0V
OL Gnd OL Gnd OL Gnd
CIRCUIT DESCRIPTIONS INVISIBLE SPEAKER SYSTEM Woofers
Tweeters
Tweeters
Bottom View of Woofer Ports
3 2 L G 4 0
DISASSEMBLY DISASSEMBLY
42LG60
INTRODUCTION This section of the manual will discuss Disassembly of the 42LG60 LCD Direct View Television. Upon completion of this section the Technician will have a better understanding of the disassembly procedures.
BACK COVER REMOVAL Remove the 13 screws shown. Pay attention to the size and type of screw as there are different types. Putting in the improper screw when reassembling may cause damage. Handle the TV carefully while the 4 stand screws are removed. The stand fits snuggly, but could fall out and cause injury. For safety, put the 4 stand screws back after removing the back cover.
DISASSEMBLY POWER SUPPLY (SMPS) REMOVAL Disconnect P2, AC In, P402, and P402. Remove the 6 screws indicated below.
MAIN BOARD REMOVAL Disconnect P401, P501, P800, P801, and P900. Note: In the bottom right is connector
DISASSEMBLY CONTROL BOARD REMOVAL Disconnect P101, P102 P103, and P104. Remove the LVDS cables by pressing in from the sides to release and then lift them out. Be careful when removing the LVDS Cables, they’re fragile. Press the release tabs to avoid damage to board or to the cable itself. Remove the 4 screws indicated below.
DISASSEMBLY SPEAKER BOX REMOVAL To remove the Speaker Box, remove the 4 screws show in circles. Then remove the wire harness. Carefully disconnect both Tweeters. Unplug P500 from the Main board. Speaker Bo x Removed
To Tweeters
DISASSEMBLY EXPLODED VIEW 300 400
200 801
804
570
803
521
901
520 830
840
805
802 510
121 560 500
120 540 810
820
580 530
900
CIRCUIT DESCRIPTIONS CIRCUIT DESCRIPTIONS
42LG60
INTRODUCTION
LCD Driver (T-CON) With shield removed
Backlight Connection Control Board
LVDS Cables
Backlight Connection
CIRCUIT DESCRIPTIONS BACKLIGHT LAYOUT Back View 18 Bulbs
Power Supply with Ballast
To Backlights
Over 1.2KV
CIRCUIT DESCRIPTIONS POWER SUPPLY LAYOUT P2 - To Main
P402 To Backlight P401 To Backlight F700 5A/250V 335V INPUT
F101 AC IN 8A/250V AC 100V ~ 240V (50/60Hz) 3A St-by 5.2V (5A)
OUTPUT
12V
(2A)
CIRCUIT DESCRIPTIONS POWER SUPPLY TEST 24 22 20 18 16 14 12 10 8 6 4 2 To test everything but the backlights. P2 Disconnect the P2 connector from the 23 21 19 17 15 13 11 9 7 5 3 1 PWR +5V Main board. With the Power Supply disconnected from other boards and AC 10K applied, confirm that the Power Supply is producing 5V from either pins 9, 10, 11 or 12. If not, check the fuse. If the fuse is ok and there’s no 5V, replace the Power Supply. If 5V is ok then continue. Remove AC power when adding the jumpers shown in the image. Apply power when making the test. Short either pins 9, 10, 11 or 12 (5V) to pin 19 (PWR) using a 10K resistor. This turns on the power supply. Confirm that the other low voltage power supplies are activated. Pins 1 and 2 should be 16V. Pins 5 and 6 should be 12V. Pin 18 (AC Detect) should go high. INV BACKLIGHT TEST 24 22 20 18 16 14 12 10 8 6 4 2 If the 1st test was successful, continue. P2 23 21 19 17 15 13 11 9 7 5 3 1 Remove the power, leave the original PWR +5V 10K in place, and add a jumper between pin pin 19 (PWR) to pin 20 (INV). Apply
CIRCUIT DESCRIPTIONS CONTROL BOARD LAYOUT P103
P104
To LCD Driver (T-CON) P101 LVDS
P102 To Main
CIRCUIT DESCRIPTIONS LVDS CABLE LVDS stands for Low Voltage Differential Signals. The LVDS cable carries video signals from the Main board to the Control board Their signals can be Press In confirmed with the Oscilloscope by monitoring the LVDS signals with no input signal selected while pressing the Menu button on and off with the remote control or keypad. Loss of these signals would confirm the failure is on the Main board. To remove the connector, press the two outside tabs inward and pull.
Locking Tabs
Press In
CONTROL BOARD CRYSTAL TEST
1.7 Vp/p
CIRCUIT DESCRIPTIONS LCD DRIVER (T-CON) LAYOUT
CIRCUIT DESCRIPTIONS LCD DRIVER (T-CON) TESTS Check the regulator US1 for correct voltage.
0V
US1 1.8V
3.2V
F1
CN1
Check Fuse F1 for 12V.
LD1
Use LD1 to determine if The boot up sequence of The T-CON is OK. If all is OK, this LED will turn bright blue shortly after power is applied then go out shortly after backlights illuminate .
LCD Driver LED Status Power Off Power 1st On Power On
CIRCUIT DESCRIPTIONS MAIN BOARD LAYOUT If odd video problems are found, use some freeze spray on IC100 and its circuits. If the video returns to normal, the board needs to be replaced. To Control Board P800
P900
P801 Power Supply IC100
CIRCUIT DESCRIPTIONS MAIN BOARD UNDERSIDE IC400
SBY 1
0.4V
RUN 3.37V
2
0V
0V
3
0.4V
3.39V
IC101
IC805
1
0.V
2
0V
IC100
3
0V
0V
Video Processor
4
0.4V
3.39V
5
0.1V
1.2V
BCM Reset
3.3V BCM 5V
CIRCUIT DESCRIPTIONS MAIN BOARD LD803 CHECK Use LD803 as a visual aid. This lets you know if the +5V is being converted to 3.3V for the BCM chip IC100. If LD803 is illuminated, +3.3V is ok. Only half of the dual LED is used.
LD803
MAIN PWB
MAIN BOARD TUNER CHECK
CIRCUIT DESCRIPTIONS Test the waveforms while using a SMTE color bar signal as the input. TDVF-H051F EBL37676801
Not Used
1
Not Used
2 3
Not Used
4
Not Used
5 6 7 8
Not Used
9 10 11 12
NC_1 RF-AGC +B (5V) VTU
Pin 14 SIF Signal
NC_2 GND SDA
850mVp/p 20nSec rate
SCL AS DIGITAL_IF1 DIGITAL_IF2 IC_AGC
Not Used 13 AUDIO_OUT SIF 14 IF_AS Not Used 15 VIDEO_OUT 16
Pin 16 Video Signal
1Vp/p 20uSec rate
17 Shield
CIRCUIT DESCRIPTIONS MAIN BOARD CONNECTORS
P501 “Main” to “Speakers” Pin Stby Run Check
SWITCHED LVDS 12V
Pin 1 3
Stby 0V 0V
P900 “Main” to P104 “Control” Run Diode Pin Stby 11.7V OL 2 0V 11.7V OL 4 0V
1
0V
8V
2.58V
2
0V
8V
2.58V
3
0V
8V
2.58V
Run Diode 11.7V OL 11.7V OL
CIRCUIT DESCRIPTIONS P801 “Main” to P2 “SMPS” Odd Label Stby Run Diode Check Even Label Stby Run Diode Check 1 16V 0V 16V 0.94V 2 16V 0V 16V 0.94V 3 Gnd Gnd Gnd 0V 4 Gnd Gnd Gnd 0V 5 12V 0V 11.8V 1.32V 6 12V 0V 11.8V 1.32V 7 Gnd Gnd Gnd 0V 8 Gnd Gnd Gnd 0V 9 5V 5V 5.15V 1.49V 10 5V 5.15V 5.15V 1.49V 11 5V 5V 5.15V 1.49V 12 5V 5.15V 5.15V 1.49V 13 Gnd Gnd Gnd 0V 14 Gnd Gnd Gnd 0V 15 Gnd Gnd Gnd 0V 16 Gnd Gnd Gnd 0V 17 ERR 3.19V 3.3V OL 18 ACD 4V 4.57V 1.85V 19 PWR 0V 2.86V OL 20 INV 0V 3.29V OL 21* ADIM 0.1V 1.68V OL 22 PDIM 0V 3.38V OL 23 SEL 0V 3.2V OL 24 SYNC 0V 0V OL (Not Used) * ADIM Pin 21 can vary according to OSD Backlight setting. 0.9V 0% to 3.3V 100%
P401 “MAIN” to “Front Keys”
CIRCUIT DESCRIPTIONS FRONT LED & POWER TOUCH
J1
Front PWB Assembly
To Main
CIRCUIT DESCRIPTIONS SIDE CONTROL PANEL
P100
To Front Control PWB
CONTROL PANEL VOLTAGES
CIRCUIT DESCRIPTIONS INVISIBLE SPEAKER SYSTEM LAYOUT Right Tweeter
Right Speaker B ox
Left Tweeter
Left Speaker B ox
Schematics
32LG40 :: INTERCONNECT 32LG40 INTERCONNECT DIAGRAM
P201 Odd " SMPS" to P800 "Main PWB"
TO TFT MODULE P203 "SMPS" to P209 "Ballast PWB" Pin
Label
STBY
Run
Diode Check
1
24V
0V
24.52V
0.33V
2
24V
0V
24.52V
0.33V
3
24V
0V
24.52V
0.33V
0V
24.52V
0.33V
5
24V
0V
24.52V
0.33V
6
4
Gnd
24V
Gnd
Gnd
Gnd
7
Gnd
Gnd
Gnd
Gnd
8
Gnd
Gnd
Gnd
Gnd
Gnd
Gnd
Gnd
Gnd
10
Gnd
Gnd
BR1
Gnd 0V
Gnd
11
9
1.67V
OL
12
INV On-Off
OL
PWM-DIM
0V 0V
3.45V
13
3.40V
OL
14
ERROR
0V
0V
OL
CN2
CN3
T-CON Board US2 3) 0.0V 2) 1.8V 1) 3.3V
12V F1 6.3V/1.5A
CN1
P201 Even "SMPS" to P800 "Main PWB" Pin Label STBY Run
Pin
Label
STBY
Run
Diode Check
1 3
16.5V Gnd
0V Gnd
1 6V Gnd
0.31V Gnd
2 4
16.5V Gnd
0V Gnd
16V Gnd
Diode Check 0.31V Gnd
5 7 9
12V Gnd 5.2V
0V Gnd 5.15V
11.8V Gnd 5.15V
1.69V Gnd 0.34V
6 8 10
12V Gnd 5.2V
0V Gnd 5.15V
11.8V Gnd 5.15V
1.69V 0V 0.34V
11 13
5.2V Gnd
5.15V Gnd
5.15V Gnd
0.34V Gnd
12 14
5.2V Gnd
5.15V Gnd
5.15V Gnd
0.34V Gnd
15 17
Gnd ERR
Gnd 0V
Gnd 3 .3V
Gnd 1.26V
16 18
Gnd ACD
Gnd 5.05V
Gnd 4.57V
Gnd OL
19
PWR
0V
2.86V
OL
20
INV-On/Off
0V
3.29V
OL
21 23
BR1 N/C
0.1V 0V
1.68V 3.2V
OL OL
22 24
PWM-DIM N/C
0V 0V
3.38V 0V
OL OL
Far left and right pins are not counted, they are ground. P902 Pin 11 To Force Power Supply On. Disconnect P800 on Main PWB. Jump 5V to pin 19. Ballast and All voltages should turn on.
P203 P202
MCN1
Example Of LVDS Signal
P201 24V LD1 Ballast Drive LED
3 2 L G 4 0
F1 8A / 150V Q901 IC809 Q900
Not Used CN403
Ballast
P800
Power Supply
CN402
Reset IC401
8 0 8 C I
Main (Digital) Board IC807
BSM IC803
IC400
CN401
P901 3.15A / 250V 380 Fuse
DVD Drive
P900
X400 24 Mhz Q400
CN400
L
X200
IC805
IC801
5A / 250V A/C Fuse F100
IC00 BCM
IC405
F101
To Backlight
Software P200 Upgrades
P902
54 Meg
TUNER
P904 LD800
IC802 IC801
IC806 A/C In
Left Side N
SC100 P401
To Backlight
Out ICs are * Grayed located on Back
Right Side P500 To Speakers
Front PWB Ass embl y (Interface)
s l o r t n o C ) y e K ( e d i S
J2
IC201 PIN 2 3 7
J1 IR Receiver Power Button
8 IC304 PIN 3,8 5 ,6, 7 4 IC400 PIN
P101
1 2 3
USB Power FUNCTION NAME STBY RUN IN +5V 0V 5V On /O f Co nt rol BC MD DR Po we r 0V 3. 4V OUT USB_PWR_Out _1 0V 5V OUT FUNCTION OUT IN O n /O f f C o nt r ol
+3.3V
0V
3.1V
2.6V BCM NAME STBY R UN DDRO_VTT 0V 1.29V D2 .6V_ BC M 0V 2. 6V
IC405 PIN 1 2 3 IC802 PIN 1 2 3
RESET GENERATOR FOR Q400 NAME STBY RUN FUNCTION IN 3.3V_MICON 3.41V 3.41V G nd Gn d Gn d G nd OUT Reset ( Lo- Hi) 0.6V 0.6V
0 V 1 . 29 V IC803 PIN FUNCTION RESET GENERATOR TO IC401 (On Back) FUNCTION NAME STBY R UN 1 IN IN Gnd OUT
D D RO _ VT T
D3.3V_BCM Gnd Reset (Lo-Hi)
0V 3.4V Gnd Gnd 0V 3.39V
2 3
4
+3.3V Regulator (3.3V TMDS_SW) FUNCTION Gnd OUT IN
Gnd OUT
NA ME +3.3V Gnd + 5V_S UB
STBY R UN 0V 5V Gnd Gnd 0V 3. 2V
+9V Regulator NAME STBY RUN +12V 0V 12V Gnd +9V
Gnd 0V
IC806 PIN 1 2 3
Gnd 9V
IC807 PIN 1 2
D3.3V/A3.3V_BCM Regulator turns on LD800 Q801 FUNCTION NAME STBY RUN PIN FUNCTION On/Off Control Power _CTL_3. 3V 0V 3.4V 1,3 IN IN + 5V_ SU B 0 .36 V 5V 2, 4 O n/ Of fCo nt rol Gnd Gnd Gnd Gnd 5,6,7, 8 OUT OUT
D3. 3V_BCM
0.1V
3.4V
Q802 5V SUB SWITCH CONTROLLER for Q801 PIN FUNCTION NAME STBY RUN D3.3V_BCM Regulator (Also A3.3V_BCM) FUNCTION NAME STBY R UN B O n / O f C o nt r ol R L _O N 0 V 3 . 29 V IN +9V 0V 8.9V C Pull Down ST_5V 0V 5V O n/ Of fC on tr ol Po we r_ CT L_ 3. 3V 0 V 3 .4 V E G nd Gn d Gn d Gn d
3
OUT
+5V
0V
5V
4 5
n/c Gnd
n/c Gnd
n/c Gnd
n/c Gnd
IC809 PIN 6,7,8,10 17 1 ,2 ,3 ,4 ,5 14,15 11,18, 19, 20
5V SUB SWITCH NAME STBY R UN ST_5V 0V 5V Q 802 0V 0 .2 8V +5V_SUB 0V 5V
D2.6V_BCM Regulator (Also A2.6V_BCM) FUNCTION NAME STBY R UN IN +5V_SUB 0.36V 4.98V On/Off Contro l Power_CTL_2.6V 0V 3.41V O UT D 2. 6V _B CM 0 V 2 .6 6V n/c n/c n/c n/c Gnd Gnd Gnd Gnd
Q400 PIN B C E
RESET GENERATOR FOR MICRO IC407 FUNCTION NAME STBY RUN Reset Reset 0.6V 0.6V V cc Gnd
3 .3 VV ST _M IC ON Gnd
0V Gnd
0V Gnd
PIN 14 1 6
FUNCTION IN OUT
PIN
Gnd
2
O UT
3
IN
PIN 6,7,8,10 17
RUN
PIN
FUNCTION
0V
3.41V
2
IN
0V 0V
3 .4 V
3
O UT
3.4V
4
Gnd
+1.8V_NTP REGULATOR
1
IC805
STBY
BCM_RESET
FUNCTION
NAME Gnd
Q900
STBY Gnd
RUN
PIN
Gnd
B
+ 1. 8V _N TP
0V
1 .8 V
C
3.3V_TMDS_SW
0.26V
3.29V
E
D1.2V/A1.2V BCM REGULATOR FUNCTION IN
NAME ST_5V 3 .3 VS T_ MI CO N Gnd
5V
Gnd
Control
NAME LVDS_PANEL_CTRL
P ul l D ow n 1 2V Gnd
LV DS S wi tc hC on tr ol Gnd
STBY
Gnd
0V
RUN 0 . 75 V
0V
0V
0V
0V
LVDS 12V SWITCH
NAME
STBY
STBY
RUN
0.38V
5V
1,3
IN
12V
0V
12.36V
0V
3. 41 V
2 ,4
O n/ Of f C on tr ol
Q 90 0
0V
6 . 16 V
0V
1 .2 9V 5 ,6 ,7 ,8
O UT
L VD S1 2V
0V
1 2. 36 V
D 1. 2V _B CM
13, 14,15,16 n/c n/c 11,12,18, Gnd Gnd 19,20 Screen Print for Pin No is incorrect, use IC
0V
0V
Gnd
Gnd
PIN
RUN
5V
3.43V 3 .4 3V
LVDS 12V SWITCH CONTROLLER Q901 FUNCTION
Q901 RUN
STBY
+5V_SUB
O n/ O f C on tr ol P ow er _C TL _1 .2 V O UT
ST-BY 3.3V DC-DC CONVERTER
IC808
NAME D3.3V_BCM
O n/ Of f C on tr ol R es et f ro mI C4 00
IC801
1 ,2 ,3 ,4 ,5
REGULATORS/ICs ON FRONT
BCM RESET
IC401
FUNCTION
NAME
REGULATORS/ICs ON BACK
32LG40 :: WAVEFORMS
3 2 L G 4 0
32LG40 LVDS CABLE WAVEFORMS: Waveforms taken using SMTP Color Bar input. All readings give the Scale and Time Base related to scope settings. Top waveform in each image gives a slower rate. 10mV at 5uS per division. Bottom waveform shows a blow up sample. 10mV at 2uS per division.
32LG40 :: MAIN BOARD :: MAIN MICRO
3 2 L G 4 0
The symbol refers to safety components. Only replace with LG parts.
32LG40 :: MAIN BOARD :: AUDIO
3 2 L G 4 0
The symbol refers to safety components. Only replace with LG parts.
32LG40 :: MAIN BOARD :: MEMORY
3 2 L G 4 0
The symbol refers to safety components. Only replace with LG parts.
32LG40 :: MAIN BOARD :: BCM/USB
The symbol refers to safety components. Only replace with LG parts.
3 2 L G 4 0
Side USB
32LG40 :: MAIN BOARD :: DCM
3 2 L G 4 0
The symbol refers to safety components. Only replace with LG parts.
32LG40 :: MAIN BOARD :: LVDS/DVD
3 2 L G 4 0
The symbol refers to safety components. Only replace with LG parts.
32LG40 :: MAIN BOARD :: TUNER POWER
The symbol refers to safety components. Only replace with LG parts.
3 2 L G 4 0
32LG40 :: MAIN BOARD :: JACKPACKS
3 2 L G 4 0
32LG40 :: MAIN BOARD :: HDMI
HDMI 1
HDMI 2
3 2 L G 4 0
42LG60 :: WAVEFORMS
LVDS CABLE P900 FROM MAIN PWB TO CONTROL PWB P101 USING SMTP COLOR BAR INPUT LAST TWO WAVEFORMS ARE FROM THE TUNER Measurements +/- 5%
4 2 L G 6 0
42LG60 :: MAIN BOARD :: BCM
4 2 L G 6 0
42LG60 :: MAIN BOARD :: DDR MEMORY
4 2 L G 6 0
42LG60 :: MAIN BOARD :: MAIN MICROPROCESSOR
4 2 L G 6 0
42LG60 :: MAIN BOARD :: AUDIO PROCESSOR
4 2 L G 6 0
42LG60 :: MAIN BOARD :: HDMI
4 2 L G 6 0
42LG60 :: MAIN BOARD :: :: INTERFACE INTERFACE
4 2 L G 6 0
42LG60 :: MAIN BOARD :: :: INTERFACE INTERFACE
4 2 L G 6 0
42LG60 :: MAIN BOARD :: REGULATORS REGULATORS
4 2 L G 6 0
42LG60 :: MAIN BOARD :: LVDS/TUNER
4 2 L G 6 0
