1080P Direct View LCD Training
42LH90
LED Backlights Original February 09, 2010 Updated July 28, 2010
OUTLINE Preliminary Section: Contact Information, Preliminary Matters, Specifications, LCD Overview, General Troubleshooting Steps, Signal Distribution, Disassembly Instructions and Voltages Disassembly Section: Removal of Circuit Boards Troubleshooting Section: Board Operation Troubleshooting of : • Switch Mode Power Supply • Inverter Board (LED Backlight Driver) • T-CON (TFT Controller) Panel Driver board • Main Board • Ft Control Board • Side Keys • Speakers 2
February 2010
LCD DV
42LH90
Overview of Topics to be Discussed
42LH90 LCD Direct View Display Section 1 This Section will cover Contact Information and remind the Technician of Important Safety Precautions for the Customers Safety as well as the Technician and the Equipment. Basic Troubleshooting Techniques which can save time and money sometimes can be overlooked. These techniques will also be presented. This Section will get the Technician familiar with the Disassembly, Identification and Layout of the LCD Display Panel. At the end of this Section the Technician should be able to Identify the Circuit Boards and have the ability and knowledge necessary to safely remove and replace any Circuit Board or Assembly.
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42LH90
Preliminary Matters (The Fine Print)
IMPORTANT SAFETY NOTICE The information in this training manual is intended for use by persons possessing an adequate background in electrical equipment, electronic devices, and mechanical systems. In any attempt to repair a major Product, personal injury and property damage can result. The manufacturer or seller maintains no liability for the interpretation of this information, nor can it assume any liability in conjunction with its use. When servicing this product, under no circumstances should the original design be modified or altered without permission from LG Electronics. Unauthorized modifications will not only void the warranty, but may lead to property damage or user injury. If wires, screws, clips, straps, nuts, or washers used to complete a ground path are removed for service, they must be returned to their original positions and properly fastened.
CAUTION To avoid personal injury, disconnect the power before servicing this product. If electrical power is required for diagnosis or test purposes, disconnect the power immediately after performing the necessary checks. Also be aware that many household products present a weight hazard. At least two people should be involved in the installation or servicing of such devices. Failure to consider the weight of an product could result in physical injury.
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February 2010
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42LH90
ESD Notice
(Electrostatic Static Discharge)
Today’s sophisticated electronics are electrostatic discharge (ESD) sensitive. ESD can weaken or damage the electronics in a manner that renders them inoperative or reduces the time until their next failure. Connect an ESD wrist strap to a ground connection point or unpainted metal in the product. Alternatively, you can touch your finger repeatedly to a ground connection point or unpainted metal in the product. Before removing a replacement part from its package, touch the anti-static bag to a ground connection point or unpainted metal in the product. Handle the electronic control assembly by its edges only. When repackaging a failed electronic control assembly in an anti-static bag, observe these same precautions.
Regulatory Information This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a residential installation. This equipment generates, uses, and can radiate radio frequency energy, and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures: Reorient or relocate the receiving antenna; Increase the separation between the equipment and the receiver; Connect the equipment to an outlet on a different circuit than that to which the receiver is connected; or consult the dealer or an experienced radio/TV technician for help.
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LG Contact Information Customer Service (and Part Sales)
(800) 243-0000
Technical Support (and Part Sales)
(800) 847-7597
USA Website (GSFS)
http://gsfs-america.lge.com
Customer Service Website
us.lgservice.com
LG Web Training
lge.webex.com
LG CS Academy
lgcsacademy.com
Presentations with Audio/Video and Screen Marks
http://136.166.4.200
LCD-DV: 32LG40, 32LH30, 37LH55, 42LG60, 42LG70, 42LH20, 42LH40, 42LH50, 42LH90, 42SL80, 47LG90, 47LH85, 47LE8500 PLASMA: 42PG20, 42PQ20, 42PQ30, 50PG20, 50PJ350, 50PK750, 50PS80, 50PS60, 60PK750, 60PS11, 60PS60, 60PS80 Also available on the Plasma Page: PDP Panel Alignment Handbook, Schematics with Bookmarks Plasma Control Board ROM Update (Jig required)
New Training Materials on the Learning Academy site
Published February 2010 by LG Technical Support and Training LG Electronics Alabama, Inc. 201 James Record Road, Huntsville, AL, 35813.
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February 2010
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42LH90
LCD Direct View Overview Safety and Handling Regulations 1. Approximately 20 minute pre-run time is required before making any picture performance adjustments from the Menu. 2. Refer to the Voltage/Current silk screening on the Switch Mode Power Supply. 3. C-MOS circuits are sensitive to static electricity. Use caution when dealing with these IC and circuits. 4. Exercise care when making voltage and waveform checks to prevent costly short circuits from damaging the unit. 5. Be cautious of lost screws and other metal objects to prevent a possible short in the circuitry.
Checking Points to be Considered 1. Check the appearance of the Replacement Panel and Circuit Boards for both physical damage and part number accuracy. 2. Check the model label. Verify model names and board model matches. 3. Check details of defective condition and history. Example: Oscillator failure dead set, etc…
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February 2010
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Basic Troubleshooting Steps Define, Localize, Isolate and Correct Look at the symptom carefully and determine what circuits could be causing •Define 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 material and give off a distinct odor. Frequency of power supplies will change with the load, or listen for relay closing etc. Observation of the front Power LED may give some clues. •Localize After carefully checking the symptom and determining the circuits to be checked and after giving a thorough examination using your senses the first check should always be the DC Supply Voltages to those circuits under test. Always confirm the supplies are not only the proper level but be sure they are noise free. If the supplies are missing check the resistance for possible short circuits. •Isolate To further isolate the failure, check for the proper waveforms with the Oscilloscope to make a final determination of the failure. Look for correct Amplitude Phasing and Timing of the signals also check for the proper Duty Cycle of the signals. Sometimes “glitches” or “road bumps” will be an indication of an imminent failure. •Correct The final step is to correct the problem. Be careful of ESD and make sure to check the DC Supplies for proper levels. Make all necessary adjustments and lastly always perform a Safety AC Leakage Test before returning the product back to the Customer.
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42LH90
42LH90 PRODUCT INFORMATION SECTION
This section of the manual will discuss the specifications of the 42LH90 LCD Direct View Display 9
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42LH90
Basic Specifications
Key TV Features • • • • • • • • • • • • • • •
LED Backlight with Local Dimming TruMotion 240Hz Intelligent Sensor Full HD 1080p 2,000,000:1 Contrast Ratio 2.4ms Response Time 500 cd/m² Brightness Wide Color gamut Super IPS Panel XD Engine 24fps Real Cinema ISFccc Ready Picture Wizard AV Mode II (Cinema, Sports, Game) NTSC / ATSC / Clear QAM
• • • • • • • • • • • • • • • • •
Audio Output Power 10W x 2 Invisible Speaker system Clear Voice II SRS TruSurround XT™ Smart Volume Controller Dolby® Digital 5.1 Decoder Backlight Control Video Mute ENERGY STAR® 3.0 Compliant 4 HDMI™ v1.3 with Deep Color SIMPLINK™ Connectivity 2 HD Component Video Inputs 2 Composite inputs 1 Digital Audio Out USB 2.0 (JPEG, MP3, MP4, Divx) PC Connectivity (D-Sub 15pin) RF Antenna Input
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42LH90
Basic Specifications (LOGO Familiarization) Full HD 1080p Resolution Displays HDTV programs in full 1920 x 1080p resolution for a more detailed picture.
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42LH90
Remote Control Familiarization
p/n MKJ61841701
TOP PORTION
BOTTOM PORTION
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42LH90
Accessing the Service Menu To access the Service Menu. 1) You must have the Service Remote. p/n 105-201M 2) Press “In-Start” 3) A Password screen appears.
Note: A Password is required to enter the Service Menu. Enter; 0000
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TV Rear Input / Output Jacks Rear In/Out Jacks
USB Port Software Upgrades Music, Photos
Side In/Out
MAIN BOARD Rear and Side Input/Output locations
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Software Download Shows the Currently Installed Version
1) Create an LG_DTV folder on the USB Flash Drive
Shows the Software Version found on the USB Flash Drive
2) Copy new software (xxx.epk) to "LG_DTV" folder. Make sure to have correct software file. 3) With TV turned on, insert USB flash drive. 4) You can see the message “TV Software Upgrade” (See figure to right) 5) Cursor left and highlight "START" Button and push “Enter” button using the remote control. 6) You can see the download progress Bar. 7) Do not unplug until unit has automatically restarted. 8) When download is completed, you will see “COMPLETE”. 9) Your TV will be restarted automatically.
* CAUTION: Do not remove AC power or the USB Flash Drive. Do not turn off Power, during the upgrade process.
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42LH90 Product Dimensions 42LH90 Dimensions There must be at least 4 inches of Clearance on all sides Wattage Average 210W Stand By <1W
42" 1066.8mm 7-7/8" 200mm
16-15/16" 430mm
28-3/16" 716.28mm
21" 533.4mm
9-5/8" 244mm
14-1/8" 357.98mm
Center
3-11/16" 93.98mm
7-7/8" 200mm
30-5/8" 777.88mm Model No. Serial No. Label
14-1/8" 357.98mm
10-5/8" 270mm Remove 4 screws to remove stand for wall mount
2-7/16" 61.6mm Weight without Stand: 43 lb Weight with Stand: 51.1 lb
17-7/8" 454mm
16
14-3/16" 360.68mm
DISASSEMBLY SECTION
Disassembly: This section of the manual will discuss Disassembly, Layout (Circuit Board Identification) of the 42LH90 LCD Direct View Television. Upon completion of this section the Technician will have a better understanding of the disassembly procedures, the layout of the printed circuit boards and be able to identify each board.
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Removing the Back Cover
Remove the 23 screws indicated. Pay attention to the size and type of screw as there are many different types. Putting in an improper screw when reassembling may Cause damage.
Decorative Plastic Cap (if used) must be removed.
Bottom two screws do not have to be removed.
The Stand does not need to be removed before removing the back.
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Circuit Board Layout TFT Panel EAJ60694101
T-CON board
INVERTER
p/n EAT60665101
p/n EAY60702001 LVDS Cables
POWER SUPPLY
p/n EAD60679428
p/n EAY58584001
Left LED Connection
p/n EAD60679364
Right LED Connection
Main Board p/n EBR62151101
Side Keys
Intelligent Sensor / IR
AC Input
Side Inputs
Rear Inputs
Tweeter R
Power Button
Moving LED
Tweeter L Full Range Speaker R p/n EAB58534501
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Full Range Speaker L
February 2010
p/n EAB58536001
LCD DV
42LH90
42LH90 Connector Identification Diagram
CN5
CN4
TFT PANEL
T-CON CN305
N/C
CN307
CN2
CN1
CN306 N/C
INVERTER P3500 P3501
P203
CN4 CN3
P3502
P201 P700
CN1
POWER SUPPLY
P1200
MAIN BOARD
N/C
P101
KEY BOARD
P600 SK100 SK101
AC In
IR P100 Main Power
LED
P103
Speakers (Front Right)
IR
Speakers (Front Left)
P101
P100
LED J1
20
Power Supply Board Removal P203
P201
Disconnect P201, P203, AC In SK100 and SK101.
P201
Remove the 6 screws indicated by the arrows. 0 10 SK
Press in Two tabs to release lock
SK101
AC In
Power Switch
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February 2010
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T-CON Board Removal STEP (1) Remove the 3 Screws in the T-CON shield and remove the shield
The two screws shown in the picture below are for the Service Position. They would have been removed when removing the shield. Be sure to reinstall them if servicing the T-CON Board. CN5
Note: Chocolate (Heat Sink Material)
STEP (2)
CN4
CN1
CN2
Disconnect CN1, CN2, CN4 and CN5. See next slide for details about removing cables.
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T-CON Board Removal Board Continued (Unlocking CN1 and CN2 LVDS Cables)
(CN1) LVDS
Press In
Pull Out
(CN2) LVDS
Press In
Pull Out
Press In
To remove the LVDS cables CN1 and CN2; Press in on the two tabs and slowly rock the cable out of the connector. (Shown by the arrows in Figure above)
Note: The tabs are fragile, use caution, they may break.
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42LH90
T-CON Board Removal Board Continued (Unlocking CN4 and CN5 LVDS Cables) To remove the flex cables to the TFT Panel, CN4 or CN5, place a soft thin object like a fingernail underneath the black locking tab and gently pull forward. (Shown by the arrows in Fig 1 and 2) Fig 1
Fig 2
CN5 or CN4 Locked Flip the lock up and back from the flex cable. Then the flex cable can be easily removed. Unlocked Fig 3 The locking tab is flipped down
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Removing the Main Board Disconnect P3500, P3501, P3502, P1200, P700 and P600
Remove any tape holding down any cables. Remove the 6 screws indicated by the arrows.
Flip the locking tab upward, pull the LVDS ribbon out.
P3500
P3502
P3501
P700
(b) Lift Out Pull Down
Press in on the top and bottom release tabs to remove.
n/c Remove decorative plastic and remove the board.
Decorative Plastic (See a and b)
P1200
P600 NOTE: Always check on top and behind the Large ICs. And look for a piece of Chocolate (Heat Transfer Material). Be sure to transfer to new Board if present.
n/c
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February 2010
LCD DV
(a) Slide Right
42LH90
Removing the Inverter Board Remove the 8 screws indicated by the arrows. Remove the Inverter Shield.
CN306
Use caution, do not allow screws to fall. Inverter Disconnect CN1, CN3, CN4 and CN306. Remove the Inverter. CN3
CN4
NOTE: Always check for Chocolate (Heat Transfer Material). Be sure to transfer to new Board if present and replace in the correct position. There should be 8 pieces on the DC to DC converter coils near the bottom right.
CN1
NOTE: If Servicing the Board, return the screws into the board to provide stability and grounding.
Chocolate
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42LH90
Removing the Inverter Board (Chocolate Notice) Back Side of the Board On the back side of the Inverter are 5 pieces of Chocolate, (Heat Transfer and Noise reduction pads). Be sure to replace these on the New Inverter if the board is replaced.
Chocolate Close Up
Be sure they do not fall off if the Inverter is removed.
Chocolate
Chocolate Location White Box Outline
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42LH90
Removing Front Boards (IR Board and Moving LED Board) Disconnect P101 and P102. Note P102 is behind the Power Switch. Remove the IR board by removing the 1 screw and lift out the board.
p/n EBR62127501
Key board p/n EBR62128101
P100
IR board / Intelligent Sensor
01 P1
P102
Tab Tab P1
00
J1
The Power Switch has been removed for easier viewing of connectors and screws.
Moving LED board (Power LEDs)
Disconnect J1 or P100. Remove the LED board by lifting up on the two locking tabs and pull backwards on the board.
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p/n EBR61674001
February 2010
LCD DV
42LH90
Removing Front Key Board p/n EBR62127501 Key Board
To Remove the Key Board, Apply Pressure at point (A) on the Key Board itself while using an object to slightly pry out from the top.
Tab Slots
(A) Push In
Tab Tab Tab Slots (B) Push In
Disconnect P100 and remove the Key Board Apply Pressure at point (B) on the Key Board itself while using an object to slightly pry out from the bottom.
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February 2010
P100
LCD DV
42LH90
TROUBLESHOOTING SECTION
Troubleshooting: This section of the manual will also discuss troubleshooting. Upon completion of this section the Technician will have a better understanding of how to diagnosis and resolve problems.
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POWER SUPPLY SECTION This switch mode power supply develops Stand By 5V at all times when AC is applied. At power on, it develops 12V and 24V for the Main board And 24V for the Inverter. This power supply draws a little less that 1 watt during stand by mode. The fuse F101 reads 159.9V (from hot ground) during this time. When the controller chip (IC501) receives the PWR-ON command via P201 Pin 19, the primary section increases its current supplying ability. The Primary fuse F101 now reads 390V. P201 Connector: (To Main Board) 12V is routed out P201 pins 5 and 6 and 24V is routed out P201 pins 1 and 2. P203 Connector: (To Inverter Board) 24V is routed out P203 pins 1 through 5.
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Power Supply (Main Power Switch Type 1) Location There are three types of Main Power switch used in LG televisions. Type 1: Shuts off AC to the Power Supply. Type 2: Opens ground to the front IR board. (Stand-By 5V Remains, the Main board stays alive). This prevents any activity of the IR or the Key Board. When the Switch is opened, a line called Power Key pulls up high when ground opens. When the switch is closed, this same line called Power Key feeds back to the Microprocessor and the Micro. Turns on the Power. Type 3: Opens ground to the front IR board. (Stand-By 5V turns off, the Main board is dead). This prevents any activity of the IR or the Key Board. When the Switch is opened, a line called Power Key pulls up high when ground opens. This line feeds back to the Main board and from there it routes to the Power Supply. The high tells the Controller chip to turn off STBY-5V. When the switch is closed, this same line called Power Key now goes high and feeds back to the Power Supply and tells the controller chip to turn STBY-5V on.
If the TV won’t come on, be sure to check the Main Power Switch before assuming a failure has occurred. This switch breaks AC to the SMPS.
MAIN POWER SWITCH LOCATION TYPE 1 (Bottom Left Side viewed from rear) On
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February 2010
Off
LCD DV
42LH90
Power Supply (SMPS) Board Layout To Main
F101 3.15A/250V Run 390V STBY 159.8V From Hot Gnd
P201 Pin 1
Components Inside the dashed line are Hot Gnd
F101 (Diode Check) Red Lead on Fuse (Open) Black Lead on Hot Ground Black Lead on Fuse (0.608V) Red Lead on Hot Ground
Hot Ground Shock Hazard
F100 5A/250V AC IN
The Left pin on SK101 goes to the Main Power Switch. The Right hand pin returns from the Main Power Switch.
N
AC IN SK101 L
To Master Power Switch SK101
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42LH90 Power Supply Turn On Sequence Main (Master) Power SW
POWER SUPPLY (SMPS) Power Supply will not be on if Main Power Switch is off.
L
Off On
L
AC In
1
In Stand-By Primary side is 160V In Run (PWR On) Primary side is 390V 5
Stand By 5V Reg
Stand By 5V
8
A-DIM Not Used
Inv On
2 3.3V_ST
IC103, Q106 Resets the Microprocessor
Other Regs Q706 (½) 5V Switch Relay On
3 At point TV is in Stand-By state. Energy Star compliant. Less than 1 Watt
Picture Content Intelligent Sensor
9
6
P-DIM Local Dimming Control Signal
IC1003 9V Reg IC1002 5V_TU Reg
2 Mstar Microprocessor IC100 3 4 (½)
7
LVDS
10
T-CON BOARD 12V 7
MAIN BOARD 8
IC3502 Dimming IC
Mstar IC100 (½)
Q706 (½)
Inv On/Off
LVDS
LVDS 12V
12V 5
Manipulates All Backlight LEDs
To Panel Right Side LEDs
Local Dimming Signal
24V Audio
Other Circuits
INVERTER
Global Dimming
8
Cust Menu for Backlight
8
Power On/Off
IC702 Reg
P-DIM
To Panel Left Side LEDs
24V B+ for Inverter
24V
5 6
6
9
24V
PWR
2
Inverter On Starts the Inverter LED Drive Signal
Inverter On
24V Regulator
12V/24V Regulators
12V
8
Inverter On
11
7 7
Video Arrives
T-CON DC-to-DC Converter generates 3.3V 16V 26V -5V
LVDS Panel Control Power On/Off
34
4
Remote
Power Button
42LH90 P700 on Main Board to SMPS Turn On Circuit 12V_TCON (LVDS 12V)
n/c PWR Gnd Gnd Gnd Gnd
1 2 3 4 5 6 7
SBY5V Gnd Gnd 12V Gnd Gnd 24V n/c INV.On A.DIM ERR n/c PWM-DIM
8
n/c 5V Gnd Gnd Gnd Gnd 5.15V 5.15V
1
14 15 16 17 18 19 20 21 22 23 24
Gnd Gnd 24.1V 24.1V n/c 4.65V 1.66V 0V n/c 3.2V
n/c
8
1
7
2
0V
5V_ST
Q703 0.2V
C711 15pF
0.6V
F6 R726 R757 10KΩ 0Ω
R251 100Ω
From IC702 3.3V_ST From IC103,Q106 Reset
Q701
L706
R706
R771
20K
0Ω
D4
12V
14
C721 68uF
16
24V
17
L707
18
C722 47uF
19
INV ON/OFF
R717 3.3KΩ
G5 R707 4.7K
100 Error Out
22
n/c
24
PWM-DIM (PWM Dimming) Manipulates the Backlight Brightness via Customer’s OSD. Manipulates the Backlight Brightness via the Video Processor chip. Darker Picture, Darker Backlights to facilitate improved Contrast Ratio. 0.6V ~ 3.3V Range
Stby = 0V Run = 0V
H6
Key 1
A4
Key 2
B4
10KΩ
C728 1uF R7141
21
Power Det
+5V_General
Q702 R719
R201 100Ω
R713 0Ω
R244 100Ω
INV_CTL
P5.3 P5.6 31
Error Out
AB13 PWM0
A-DIM L700
Analog Dimming (Fixed Value)
R704 4.7K
C706 1uF
R185 100Ω
GPIO-09
Digital Dimming (Variable) R760 PWM-DIM L705
35
C725 1uF
0
R189 100Ω
H5 R245 100
Error=5V: Normal 0V: Micro shuts off television.
+5V_ST
L704
15
RL_ON
PANEL_CTL
C726 220uF
13
Reset
R257 100Ω
5.2V
12
Power On/Off
IC100 Micro
E5
RL_ON
11
23
Q704
0.6V
PWR ON
8
20
Q705
R740 47KΩ
7
10
11.9V
4
6
10
11.9V
5
L709 L701
5
9
13
+5V_General
4
5.15V Gnd Gnd
3
3
9
12
+5V
2
5.15V
11
6
L708
R739 47KΩ
L715
MAIN BOARD P700
SMPS P201
12V
Q706
L728
AD12 PWM2
Power Supply Board Low Voltage Test 1 AC Should not be applied at any time while adding resistors or while unplugging connectors as damage to the circuit Board may occur. a) When AC is applied, the SMPS “MUST” be producing STBY 5V on pins 7, 8, 9 or 10 of P201. If 5V Standby is not being generated, the SMPS is defective and must be replaced. There is no need to continue with the next test. But, make sure the Main Power Switch is On. (b) Unplug P700 on the Main Board to make insertion of the Resistors much easier. TEST 1:
No Backlights during this test
(1) Add a 100Ω resistor between (5V STBY) pin 7, 8, 9 or 10 and Pin 2 (PWR). Apply AC. This will turn on the power supply. a) Check that the 24V and 12V power supplies are turned on, • P201 (24V pins 17 and 18) • P201 (12V pins 13 and 14) • P203 (24V pins 1 through 5) to the Inverter. (2) Remove AC power.
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February 2010
Use P700 Side to insert resistors
LCD DV
42LH90
Power Supply Board Backlights Test 2 P700 Connector disconnected from the Main Board. Apply AC after adding jumper. Continue if the 1st test was OK. Leave original resistor in place. (3) Add another 100Ω resistor between (5V) pin 7, 8, 9 or 10 and Pin 20 (INV On). (4) Apply AC Power. Simulating a Power and Backlight On command. Backlights Normal: a) If normal, the backlights should turn on. SMPS OK, Inverter OK. Backlights Abnormal: a) Recheck all connections. b) Confirm the INV On/Off line pulling up to at least 3V. REMOVE AC POWER: c) Check the connections to the Inverter. If the 24V was arriving at the Inverter in Test 1 (pins 1~5 of P203) and the Inverter On command (INV-ON pin 12 of P203) is arriving, then see Inverter Section for further testing. Use P700 Side to insert resistors
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Power Supply Connector P201 Voltage and Diode Check P201 Odd "SMPS" to P601 "Main"
P201 Even "SMPS" to P601 "Main"
Pin
Label
STBY
Run
Diode Check
Pin
STBY
Run
Diode Check
23
nc
nc
nc
Open
24
2
PDIM
0V
3.2V
Open
A.DIM
0.47V
1.66V
Open
22
Err Out
0V
0V
Open
19
nc
nc
nc
Open
20
INV.ON
0V
4.65V
Open
17
24V
0V
24.1V
0.74V
18
24V
0V
24.1V
0.74V
15
Gnd
Gnd
Gnd
Gnd
16
Gnd
Gnd
Gnd
Gnd
13
12V
0V
11.9V
0.98V
14
12V
0V
11.9V
0.98V
11
Gnd
Gnd
Gnd
Gnd
12
Gnd
Gnd
Gnd
Gnd
9
5.2V
5.15V
5.15V
Open
10
5.2V
5.15V
5.15V
Open
7
5.2V
5.15V
5.15V
Open
8
5.2V
5.15V
5.15V
Open
5
Gnd
Gnd
Gnd
Gnd
6
Gnd
Gnd
Gnd
Gnd
3
Gnd
Gnd
Gnd
Gnd
4
Gnd
Gnd
Gnd
Gnd
1
nc
nc
nc
Open
2
PWR
0V
5.0V
1.6V
21
1
1
Label
2
ADIM Pin 21 Fixed and not used
PDIM Pin 24 can vary according to type of signal being processed and the OSD Backlight setting. 0.33V 0% to 3.3V 100%. Output from the Video Processor IC100.
Diode Mode values taken with all Connectors Removed
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February 2010
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42LH90
Power Supply Connector P203 Voltage and Diode Check P203
P203 "SMPS" to CN4 “Inverter" Pin
Label
STBY
Run
Diode Check
14
ERR
0V
0V
Open
P-DIM
0V
3.2V*
Open
INV_ON
0V
4.65V
Open
A.DIM
0.47V
1.66V
Open
6~10
Gnd
Gnd
Gnd
Gnd
1~5
24V
0V
24.0V
0.74V
13 13 11
1
2
1
ADIM Pin 11 Fixed and not used
2
P-DIM Pin 24 can vary according to type of signal being processed and the OSD Backlight setting.
*0.6V 0% to 3.3V 100%. Output from the Video Processor IC100.
Diode Mode values taken with all Connectors Removed
39
February 2010
LCD DV
42LH90
Power Supply Connector SK100 and SK101 Voltage and Diode Check Diode Mode values taken with all Connectors Removed
SK100 "SMPS" to AC IN Pin
Label
E3
L
E7
N
STBY
Run
SK101 "SMPS" to MASTER POWER SWITCH Diode Check
Pin
Label
OL
E4
n/a
OL
E5
n/a
120Vac
AC Voltage Readings (From Hot Ground) Pins 1 and 2 for STBY and RUN.
Bottom Right of SMPS
F100 8A/250V AC IN
F100
E4
Run
120Vac
Diode Check OL OL
AC Voltage Readings for either pin 1 or pin 2 in STBY and RUN with one lead on Neutral of SK100. (Reading from Hot Ground) Note: With Main Power Switch Open, E5 has no AC. E4 does have AC. With the Master Power Switch Closed (On) AC flows. When Open (Off) AC open and does not flow. F100 (Diode Check) Main Power Switch Closed
E7
E5
STBY
Neutral E3
Red Lead on Fuse (Open) Black Lead on Hot Ground Black Lead on Fuse (0.525V) Red Lead on Hot Ground
SK101
Live
SK100 40
February 2010
LCD DV
42LH90
INVERTER (LED BACKLIGHTS) SECTION The Inverter receives 24V from the SMPS on CN1 pins 1~5.. The Inverter On (INV ON) command from CN1 pin 12 starts the Inverter drive signals. P-DIM is delivered from the Main board through the SMPS to the Inverter on CN1 pin 13. The Inverter is responsible for delivering B+ (27.5V) to each of the 64 LED Blocks. This is accomplished by 4 DC to DC Converters (M1~M4) on the board, (easily identified by the 4 yellow capacitors on the lower left of the board. • •
M1 and M3 are routed out CN4 M2 and M4 are routed out CN3.
It also must deliver grounding pulses (Drive Signals) to each of the 64 LED Blocks. This is accomplished by the 32 switching components Q19~Q50 each controlling 2 blocks. The Left hand connector CN3 connects the 4 LED Boards (32 blocks) on the right side of the screen and the Right hand connector CN4 connects to the 4 LED Boards (32 blocks) on the left.
41
February 2010
LCD DV
42LH90
42LH90 LED Backlight Controls (Block Diagram) CN3 Controls 4 Boards Each board controls 2 rows of 4 Blocks. Total 8 Blocks
(Pin 6) 3.46Vp/p (Pin 4) 3.48Vp/p
INVERTER
(Pin 1) 3.54Vp/p
CN306
CN4/CN5 carry To Panel -5V, 3.3V, 16V, 26V and CN5 CN4 Video for Panel T-CON LVDS 12V T-CON develops Luminance Manipulated by -5V, 3.3V, 16V, the Brightness Setting 26V for Panel
Local Dimming Control Signals
Pulling CN306 will place all LEDs in full bright.
CN1
M2-M4
Quad 12 Bit LVDS Video
LVDS 12V
CN3 To LED Backlights
CN2
Drive Signals for CN3 and CN4 going to V1 through V64 (LED Blocks) Freq: 120Hz Bright CN4 Controls 4 Boards Each board controls 2 rows of 4 Blocks. Total 8 Blocks
Drive Signal Medium
Dim
CN4 M1-M3
24V INV-ON
ON/OFF (Inverter On/Off) CN1
24V
P203
SMPS 12V 24V STBY 5V
PWR
P201
Error ON/OFF (Inverter On/Off)
42
P-DIM
Customer’s Menu Brightness Selection Only affects Luminance information
Error
Backlight setting determines the Backlight brightness Ceiling
P700
PWM-DIM (Global Dimming) Customer’s Menu Backlight Selection Only affects P-DIM
12V Switch Q706
12V
Drive Signal
27.6V
LVDS 12V 8 LEDs Per/block IC3502 Dimming Tur-Motion
Panel CTL
STBY 5V, 12V, 24V PWR (Power On) Inv On/Off PWM-DIM
Relay On
DC Voltage Manipulated by: Video Content Intelligent Sensor Customer’s Menu Backlight Setting
Quad 12 Bit LVDS Video
P3501
Error VBR-B PWM-DIM (Global Dimming)
There are two DC to DC converters (27.6V) for each plug CN3/CN4 Called M1-M4
120Hz Backlight Blanking Signal
IC801 XD Engine Luminance 12 Bit LVDS Video I100 Mstar Chip
MAIN BOARD
Intelligent Sensor (Room Light Monitor) Only affects P-DIM
Inverter Connector Identification CN305 n/c
CN306
CN307 n/c
CN3
CN4
Chocolate
CN1 M1
27.5V Power Supplies
M2
M3 M4
43
February 2010
LCD DV
42LH90
General LED Backlight Board Information (As viewed from the Front)
There are 4 LED Boards per/side, 8 Total. There are 2 Rows of LED blocks per/board. There are 4 LED blocks per/row.
44
February 2010
LCD DV
42LH90
General LED Backlight Block Information 9.4V p/p 120 Hz
Connected to CN3 or CN4
There are 8 LEDs per/block. There are a total of 512 LEDs.
45
February 2010
LCD DV
42LH90
LED Backlight Basics (LED Layout) The picture below shows a close up of one of the 512 individual LEDs contained within the backlight boards. There are two sides each with 256 LEDs (32 blocks) in each side. An individual block is manipulated by the Main board Dimming IC IC3502 in accordance with the video intensity at the specific location of the block of LEDs for that video content (Local Dimming). In other words, if the video is dark in the area of the screen that is being illuminated by a block of LEDs, they will be dimmed. Also, all blocks are manipulated simultaneously via (Global Dimming) by IC100 Video Processor. The Overall intensity of the backlights is manipulated by the “Global Dimming” signal from the Mstar (IC100) chip called Digital-Dimming (PWM-DIM). A minimum of 21V required to light all 8 LEDs in a block Pins 1,2,13,14,16,17,28,29,31,32,43,44,46,47,58,59 On CN3 and CN4 Panel Disassembly required. (Not during warranty period.) A simple Forward Bias diode check will cause the diode to illuminate if it is good. Check any pin on the right to any pin on the left.
This represents One Block. There are 4 boards per/side. Each board contains 8 Blocks. Totaling 32 Blocks per/side. 64 Blocks over all. In the Diode Mode Check, the LED will light. (2.6V Reading)
46
February 2010
LCD DV
42LH90
LED Backlight Basics (Local Dimming) The graphics below show the relationship between the LEDs reaction to real time video on the screen, this is called “Local Dimming”. The areas in the picture on the left shown by A, B, C and D show the dark areas of the screen. The picture on the right shows the backlight LEDs. Note they are dimmed out in the same area as the dark video on the left.
(A)
(B)
(C)
(A)
Actual Video capture
(B)
(C)
Actual LED reaction capture
To see a representation of the “Local Dimming” the TV has to be set to the “Store Mode”. Note: These graphics are from the 47LG90 which has more LEDs than the 42LH90, but the explanation remains the same.
47
February 2010
LCD DV
42LH90
Inverter Component Identification
48
February 2010
LCD DV
42LH90
Inverter 27V (M 1-M4 Power Supplies) Information
M1
There are actually 4 power supplies developing the operational B+ (27.5V) for the LED blocks. They are designated as “M1 through M4”. Each of the 4 have the same components.
M2 27.5V TP
M3
M4 Each of the 4 capacitors C12, C27, C212 and C227 have a TP just above the (+) leg of the cap.
49
February 2010
LCD DV
42LH90
Inverter Component Top Half Identification Local Dimming Control Signals To P306 from Main
D302 blinks at 1Hz when all is OK Example: Q35 Q35 - Q50 Are LED Block Drivers for CN3
Q19 - Q34 Are LED Block Drivers fro CN4
Example
Q19 through Q50 Note: Each output driver (switch) has a TP to the left and right representing a “V” which indicates a Block of LEDs. In the example Q35 above; V34 represents Pin 23 of CN4 V33 represents Pin 24 of CN4 Grounding these points when the 27.6V supplies are working will cause the entire Block of Backlight LEDs to turn on. (100mA to light one block)
Voltage Supplies to each connector. CN3 27.5V Line on CN3 Pins 1-2 (Out_M2) Pins 13-14 (Out_M2) Pins 16-17 (Out_M2) Pins 26-29 (Out_M2) Pins 31-32 (Out_M4) Pins 43-44 (Out_M4) Pins 46-47 (Out_M4) Pins 58-59 (Out_M4)
50
February 2010
CN4 27.5V Line on CN4 Pins 1-2 (Out_M3) Pins 13-14 (Out_M3) Pins 16-17 (Out_M3) Pins 26-29 (Out_M3) Pins 31-32 (Out_M1) Pins 43-44 (Out_M1) Pins 46-47 (Out_M1) Pins 58-59 (Out_M1)
LCD DV
42LH90
Inverter LED D302 Information
LED D302
LED D302 blinks at 1Hz to indicate that the Inverter is running correctly. When it blinks at any other rate, it indicates there is an abnormal state of the Inverter. When it doesn’t blink, check the 24V arriving at the board on CN1 pins 1~5. Check the two fuses F1 and F2 for 24V. Check IC302 and IC303 regulator voltages (see page 56).
51
February 2010
LCD DV
42LH90
Inverter Fuse F1 and F2 Check
Center of the Board Left of CN1 Connector
F1 2A/125V
F2 12A/65V
F1 or F2 Normal 24V in Run
F1 or F2 (Diode Mode Check) Open (Red Lead on Fuse) 0.46V (Black Lead on Fuse)
52
February 2010
LCD DV
42LH90
Inverter Crystal Y301 Information Crystal Y301
53
February 2010
LCD DV
42LH90
Inverter 27V (M 1-M4 Power Supplies) Checks There are actually 4 power supplies developing 27.5V for the LED blocks. They are designated as “M1 through M4” This one is M3. Each of the 4 have the same components.
Example of M3 (27.5V) Power Supply
Q4, Q5, Q11, Q11, Q12, Q204, Q205, Q211, Q212 Gnd
3.67V
23.9V D2, D3, D7, D8, D202, D203, D207, D208 26.4V 28.0V
Gnd Gnd
3.74V Gnd
4.0V
3.73V 6.75V
Q2, Q10, Q202, Q210
4.0V
Q3, Q09 Q203, Q209
54
February 2010
LCD DV
42LH90
Inverter IC2, IC4 and IC15 Checks IC4
Center of the Board
GND 3.29V 6.99V
IC15
IC2 1.0V
7V
4.6V GND 24V
0.46V 1.71V 6.95V
GND
55
February 2010
LCD DV
42LH90
Inverter IC303 and IC302 Checks (Controller IC301 B+) Top of the Board 3.3V 7.0V
GND
IC303
IC302 GND
7.0V 1.8V
56
February 2010
LCD DV
42LH90
Inverter Board Connector CN3, CN4 to the Panel (Voltage and Diode Check) CN3 Inverter to Panel Pin 1~2
Inverter Run voltages taken with built in test pattern full white screen
3
Resistance
27.0V
OPEN
Pin 60
0V
OPEN
58~59
Run
Resistance
n/c
Label
0V
OPEN
Out_M1
27V
OPEN
V8~V5
0.7-1.2V
OPEN
57
0V
OPEN
8~11
V13~V16
0.7-1.2V
OPEN
53~56
V4~V1
0.7-1.2V
OPEN
0V
OPEN
49~52
V9~V12
0.7-1.2V
OPEN
OPEN
48
0V
OPEN
46~47
Out_M1
27.0V
OPEN
45: n/c
n/c
OPEN
43~44
Out_M1
12 13~14 16~17 18
n/c Out_M2 n/c Out_M2 n/c
27.0V
0V
n/c
n/c
OPEN OPEN
0V
OPEN
27.0V
OPEN
V24~V21
0.7-1.2V
OPEN
42
0V
OPEN
23~26
V29~V32
0.7-1.2V
OPEN
38~41
V20~V17
0.7-1.2V
OPEN
27: n/c
n/c
0V
OPEN
34~37
V25~V28
0.7-1.2V
OPEN
OPEN
33
0V
OPEN
31~32
27.0V
OPEN
30
OPEN
28~29
30 31~32 33
Out_M2 n/c Out_M4 n/c
27.0V
0V
n/c
0V 27.0V
19~22
28~29
n/c Out_M1 n/c Out_M3
OPEN OPEN
0V
OPEN
27.0V
OPEN
0V
OPEN
V40~V37
0.7-1.2V
OPEN
27
38~41
V45~V48
0.7-1.2V
OPEN
23~26
V34~V33
0.7-1.2V
OPEN
OPEN
19~22
V41~V44
0.7-1.2V
OPEN
0V
OPEN
27.0V
OPEN
0V
OPEN
27.0V
OPEN
0V
OPEN
42 45 46~47 48
n/c
0V
Out_M4
27V
OPEN
18
n/c
0V
OPEN
16~17
Out_M4 n/c
27V 0V
OPEN
V56~V53
0.7-1.2V
OPEN
53~56
V61~V64
0.7-1.2V
OPEN
58~59 60
n/c Out_M4 n/c
0V
13~14
OPEN
49~52 57
15 12
OPEN
27.0V
OPEN
0V
OPEN
n/c Out_M3 n/c Out_M3 n/c
8~11
V52~V49
0.7-1.2V
OPEN
4~7
V57~60
3 1~2
57
n/c
0V 27.0V
34~37
43~44
Note 46-47 Incorrect Silk Screening on Board.
n/c
Run
4~7
15
Diode Mode values taken with all Connectors Removed
Label Out_M2
CN4 Inverter to Panel
0.7-1.2V
OPEN
n/c
0V
OPEN
Out_M3
27V
OPEN
February 2010
LCD DV
42LH90
Inverter Board Connector CN1 to the P203 “SMPS” (Voltage and Diode Check) Inverter Run voltages taken with built in test pattern full white screen CN1 Connector “Inverter” to P203 “SMPS” Error
P-DIM Ext_VBR_B (P-DIM) Pin 13 can vary according to type of signal being processed and the OSD Backlight setting. 0.33V 0% to 3.3V 100%. Output from the Video Processor IC100.
Pin
Label
STBY
Run
Diode Mode
14
AGP
0V
0V
OPEN
13
Ext_VBR_B
0V
0.33V-3.2V
OPEN
12
ON/OFF
0V
4.65V
1.6V
11
NC
0.47V
1.66V
OPEN
10
GND
GND
GND
GND
9
GND
GND
GND
GND
8
GND
GND
GND
GND
7
GND
GND
GND
GND
6
GND
GND
GND
GND
5
VIN
0V
24.0V
2.9V
4
VIN
0V
24.0V
2.9V
3
VIN
0V
24.0V
2.9V
2
VIN
0V
24.0V
2.9V
1
VIN
0V
24.0V
2.9V
Diode Mode values taken with all Connectors Removed
58
February 2010
LCD DV
42LH90
Inverter Board Connector CN306 to the P3501 “Main” (Voltage and Diode Check) Inverter Run voltages taken with built in test pattern full white screen CN306 Connector “Inverter” to P3501 “Main” Pin
Label
STBY
Run
Resistance
8
GND
0V
0V
GND
7
GND
0V
0V
OPEN
6
Dclk
0V
0V
OPEN
5
GND
0V
0V
OPEN
4
*Din
0V
0.7 TO 3.0V*
OPEN
3
NC
0V
0V
OPEN
2
NC
0V
0V
OPEN
1
Scel
0V
0.02V
OPEN
* Local Dimming Off 0.85V
Diode Mode values taken with all Connectors Removed
59
February 2010
LCD DV
42LH90
T-CON (TFT DRIVE) BOARD SECTION
LCD Panel Controller Board The T-Con Processor UC1 receives from the Main Board via CN1 dual 12 Bit LVDS (Video) Signals and CN2 dual 12 Bit LVDS (Video) Signals. Both LVDS cables are carrying 24 bit signals. UC1 then processes these signals into TFT Drive Signals. It delivers its output signals through connectors CN4 and CN5 to drive the LCD Panel. 12V is supplied to the T-Con Board on connector CN1 from the Main Board (easily measured at fuse F1). There is one regulator that creates 1.8V developed at pin 2 (Center Leg) of U11. U5 is a DC to DC converter IC which develops the Panels driver voltages. 16V, 3.3V, -5V and 26V. These voltages can be read at the ribbon connector or at test points on the board which will be identified later. 60
February 2010
LCD DV
42LH90
T-CON (TFT Drive) Board (Shield Removed) To TFT Panel
To TFT Panel
T-CON p/n: EAT60665101
CN5
CN4
FL2 D9
U12 D7 FL1
D10
UC1 U11
U5 Q1 D8
F1 U10
CN1 Remember to replace screws for ground purposes if testing the Board.
CN2
To Main Board
61
February 2010
LCD DV
42LH90
42LH90 T-CON (TFT Drive) Board Drawing (Components and Voltages Identified) -4.9V 26V
Pin 3,4,5 16V Pin 7,8 3.3V
Pin 56,57,58 16V Pin 53,54 3.3V
TO TFT MODULE
T-CON (TFT Driver)
CN5
CN4 FL2
P/N EAT60665101
VCC 3.3V
Gnd Protect L2
U12
Gnd D9 3.3V
D7
1) Gnd 2) Gnd 3) Gnd 4) Gnd
U5 B+ ( 12V ) C 3.3V
1) 0V 2) 1.19V 3) 3.3V
U10
-4.9V 27V D10 14.25V
UC1
2 U11
FL1 Gnd Protect
-2.4V 20.5V
U5 26V
L1
16V R702 R701
Q1
8) 3.34V 7) 3.09V 6) 3.34V 5) 3.34V
125V / 3A
F1 (12V)
B E 2.78V 3.3V
16V ( 12V )
D8 16V
CN1
CN2
12V LVDS Pins 48~51
62
C744 R721
3
2
-4.9V 26V
TO TFT MODULE
TO TFT MODULE
1
Pin 2 Pin 4
R704 R705 R706
Pin 59 Pin 57
VDD
T-CON (TFT Drive) Board Checks
T-CON Board
U11 has a piece of “Chocolate” which is heat transfer material. Transfer if board is replaced.
Check Fuse F1 for 12V from CN1 Pins 48~51
U11 0V 1.8V
F1
3.3V Check the Regulator U11 for Correct Voltage
CN1 F1 (Diode Mode Check) Open (Red Lead on Fuse) 0.46V (Black Lead on Fuse)
63
February 2010
LCD DV
42LH90
T-CON (TFT Driver) Board CN4 and CN5 (Voltage Sources) 3.3V TP VCC
-5V Source D9 Anode
D7 12V Pin 25,26 Chip B+
D7 Cathode 3.3V
26V Source Pin 8
U5
3.3V Source Pin 23, 24 12V Pin 37,38 Chip B+
T-CON Board
16V (VDD) Pin 42
16V (D6) Not for Panel
Cathode 16.9V
64
February 2010
LCD DV
42LH90
T-CON (TFT Driver) Board CN4 and CN5 (Voltage Check) 3.3V Pin 7,8
3.3V Pin 53,54
CN5
-5V Pin 59
CN4
16V Pin 3,4,5 26V Pin 57
16V Pin 56,57,58
-5V Pin 2 26V Pin 4
CN5
CN4
T-CON Board
65
February 2010
LCD DV
42LH90
T-CON Board Connector CN1 to the Main Board (Voltage and Diode Check) CN1 “T-CON“ to P3500 CONNECTOR "Main" Pin
Label
Run
Diode Test
Pin
Label
Diode Mode values taken with all Connectors Removed
Run
Diode Test
Pin
Label
Run
Diode Test
1
Gnd
Gnd
Gnd
21
Gnd
Gnd
Gnd
41
URSA-B4M
1.09V
Open
2
n/c
n/c
n/c
22
URSA-A3P
1.4V
Open
42
Gnd
Gnd
Gnd
3
n/c
n/c
n/c
23
URSA-A3M
1.1V
Open
43
Gnd
Gnd
Gnd
4
n/c
n/c
n/c
24
URSA-A4P
1.4V
Open
44
Gnd
Gnd
Gnd
5
n/c
n/c
n/c
25
URSA-A4M
1.1V
Open
45
Gnd
Gnd
Gnd
6
n/c
n/c
n/c
26
Gnd
Gnd
Gnd
46
Gnd
Gnd
Gnd
7
LVDS-Sel
n/c
Gnd
27
n/c
n/c
n/c
47
n/c
n/c
n/c
*8
PWM-DIM
n/c
Open
28
URSA-B0P
1. 4V
Open
48
LVDS 12V
12V
Open
9
OPC-Out
n/c
Open
29
URSA-B0M
1.1V
Open
49
LVDS 12V
12V
Open
10
OPC-EN
n/c
Open
30
URSA-B1P
1.4V
Open
50
LVDS 12V
12V
Open
11
OPC-Out2
n/c
Open
31
URSA-B1M
1.1V
Open
51
LVDS 12V
12V
Open
12
URSA-A0P
1.3V
Open
32
URSA-B2P
1.21V
Open
13
URSA-A0M
1.2V
Open
33
URSA-B2M
1.22V
Open
14
URSA-A1P
1.3V
Open
34
Gnd
Gnd
Gnd
15
URSA-A1M
1.2V
Open
35
URSA-BCKP
1.21V
Open
16
URSA-A2P
1.4V
Open
36
URSA-BCKM
1.22V
Open
17
URSA-A2M
1.4V
Open
37
Gnd
Gnd
Gnd
18
Gnd
Gnd
Gnd
38
URSA-B3P
1.2V
Open
19
URSA-ACKP
1.25V
Open
39
URSA-B3M
1.21V
Open
20
URSA-ACKM
1.26V
Open
40
URSA-B4P
1.44V
Open
66
February 2010
LCD DV
42LH90
T-CON Board Connector CN2 to the Main Board (Voltage and Diode Check) CN2 “T-CON“ to P3502 CONNECTOR "Main" Pin
Label
Run
Diode Test
Diode Mode values taken with all Connectors Removed Pin
Label
Run
Diode Test
1
n/c
n/c
n/c
21
URSA-C3M
1.2V
Open
2
n/c
n/c
n/c
22
URSA-C4P
1.13V
Open
3
n/c
n/c
n/c
23
URSA-C4M
1.18V
Open
4
n/c
n/c
n/c
24
Gnd
Gnd
Gnd
5
n/c
n/c
n/c
25
Gnd
Gnd
Gnd
6
n/c
n/c
n/c
26
URSA-D0P
1.29V
Open
7
n/c
n/c
n/c
27
URSA-D0M
1.25V
Open
8
n/c
n/c
n/c
28
URSA-D1P
1.29V
Open
9
Gnd
Gnd
Gnd
29
URSA-D1M
1.3V
Open
10
URSA-C0P
1.28V
Open
30
URSA-D2P
1.3V
Open
11
URSA-C0M
1.2V
Open
31
URSA-D2M
1.2V
Open
12
URSA-C1P
1.3V
Open
32
Gnd
Gnd
Gnd
13
URSA-C1M
1.2V
Open
33
URSA-DCKP
1.23V
Open
14
URSA-C2P
1.3V
Open
34
URSA-DCKM
1.29V
Open
15
URSA-C2M
1.2V
Open
35
Gnd
Gnd
Gnd
16
Gnd
Gnd
Gnd
36
URSA-D3P
1.3V
Open
17
URSA-C2P
1.23V
Open
37
URSA-D3M
1.25V
Open
18
URSA-C2M
1.23V
Open
38
URSA-D4P
1.4V
Open
19
Gnd
Gnd
Gnd
39
URSA-D4M
1.15V
Open
20
URSA-C3P
1.3V
Open
40
Gnd
Gnd
Gnd
41
Gnd
Gnd
Gnd
67
February 2010
LCD DV
42LH90
MAIN BOARD SECTION The Main board receives its operational B+ from the Power Supply via P400. There are two LVDS cable feeds that go to the T-CON (TFT Driver) section. These carry the duel 12 bit LVDS Video signals and the TruMotion 60Hz duel 12 bit LVDS. These signals have already been prepared for the T-CON board. The Main board also includes the Tuner, Audio and Audio/Video inputs and selection circuits. Input Voltages from SMPS. RUN
STAND-BY • STBY 5V pins 7~10
• 12V pins 13 and 14 • 24V pins 17 and 18.
The Main board also develops several B+ sources on the board. STAND-BY VOLTAGES • 3.3V_ST
GENERAL • 5V_General • 5V_EXT
LVDS • LVDS 12V (Not generated, but switched from the 12V arriving from the SMPS.
AUDIO • 3.3V • 1.8V
TUNER and VSB CIRCUIT • 9V which is used to make 5V TU • 5V TU • 3.3V • 1.2V
Mstar IC100 Video and Micro Processors • 1.2V IC3502 Tru-Motion and Dimming IC. • 1.26V_MEMC, 1.8V_MEMC, 1.8V_DDR, and 3.3V
68
February 2010
LCD DV
42LH90
Main Board Layout
To Panel P3500
P3502
SW3500 Not used
IC3502 Dimming Tru-Motion
P3501 to Inverter
X3500 P700 to SMPS
IC100 Micro/Video Processor
VIDEO PROCESSOR IC100 and Tru-Motion IC3502 runs Hot. This is normal.
DDR
DDR
n/c
X800 IC801
SW100 Reset P1200 to IR Board
USB
P600 to Speakers
X100
HDMI Selector
IC600 Audio Tuner TU1001 Rear Inputs
69
February 2010
LCD DV
42LH90
P3502
P3500
42LH90 Main Board (Front Side) Component Layout
12V LVDS Pins 1~4 IC3504
SW3500 Not Used
TruMotion/ Dimming
IC3503
P3501
42LH90 MAIN BOARD
IC3502
IC3500
IC3502 Operates at high temperature Q706
IC704
P700
L726
X3500 25Mhz
E B C
Q702 IC706
IC901
IC2
IC705
L710
Q701
IC801
X800 12Mhz
L718 IC701
E B
XD Engine
IC105
IC900
P101 N/A
C
IC1 IC101 C
P600 L607
C
E B
L712
Q100
SW100
P1200
X100 12Mhz
IC1000
IC100 Micro/Video Processor Mstar
IC1001 D1000 X1005 25Mhz
Q106
IC600
IC707
IC708 E B
IC1004 IC502
IC1002 L606
IC1203
Analog Video (19) SIF (16)
TU1001 Tuner TDVW-H103F
Dig DIF- (13) Dig DIF+ (12) Clock (9) Data (8)
Q1200 B C E
Tuner 5V_TU (4)
(1)
70
42LH90 Main (Front Side) Component Voltages Serial Flash Memory 0.05V 3.2V 2.5V Gnd 0V 0V 3.3V 3.3V
IC705
Pin [1] [2] [3] [4] [5] [6] [7] [8]
HDCP EEPROM Gnd Gnd 3.29V Gnd 3.3V 3.3V 0V 3.3V
IC706
Pin [1] [2] [3] [4] [5] [6] [7] [8]
IC101
IC105
IC701
+1.8V_DDR Regulator
Pin [1] [2] [3] [4] [5] [6] [7] [8]
0V 3.2V 3.2V n/c n/c 1.8V 0.8V Gnd
Pin [1] [2] [3] [4] [5] [6] [7] [8]
+3.3V_FE Regulator 0.8V Gnd 5V 7.5V 5V 3.3V 3.3V 2.1V
IC704
Pin [1] [2] [3] [4] [5] [6] [7] [8]
+1.26V_VDDC Regulator 0.8V Gnd 5V 6V 3.2V 1.2V 1.26V 5V 5V_EXT Memory
Pin [1] [2] [3] [4] [5] [6] [7] [8]
0.8V Gnd 12V 9.6V 5V 4.97V 4.97V 1.9V
Pin [1] [2] [3] [4] [5] [6] [7] [8]
+1.8V_MEMC Regulator 0.8V Gnd 4.92V 6.5V 4.8V 1.8V 1.8V 4.8V
Pin [1] [2] [3] [4] [5] [6] [7] [8]
+1.26V_MEMC Regulator Gnd 0.8V 1.26V 1.26V 1.8V 5V 1.26V 5V
IC707
IC708
Pin [1] [2] [3] [4] [5] [6] [7] [8]
+1.26V_PVSB Regulator 0V 3.39V 3.4V 0V 0V 1.21V 0.8V Gnd
Pin [1] [2] [3] [4] [5]
+3.3V_PVSB +3.3V_FE 4.94V 4.94V Gnd 3.4V 1.25V
Pin [1] [2] [3] [4] [5]
+5V_TU Tuner 8.92V 1.88V 5.04V 0V Gnd
Pin [1] [2] [3] [4] [5]
SPIF Optical Audio 1.58V 3.2V Gnd 1.61V 3.21V
IC1000
IC1001
IC1002
IC1203
IC3500
+3.3V_Dimming Pin Regulator [1] Gnd [2] 3.3V [3] 5V
71
IC3503
+1.8V Reg Pin Dimming [1] 0.58 [2] 1.8V [3] 3.19V
IC3204 Pin [1] [2] [3] [4] [5] [6] [7] [8]
Dimming EEPROM Gnd Gnd Gnd Gnd 3.3V 3.3V 0V 3.3V
Q100
W/P IC101 Pin B 0V C 2.5V E Gnd
Q106
S5/S6 Reset Pin Mstar B 0V C 3.28V E 0V
Q702
INV_ON Pin Inverter B 0.05V C 4.66V E Gnd
Q706 Pin [1] [2] [3] [4] [5] [6] [7] [8]
+5V/12VLVDS Switch 5.1V 0.29V 11.9V 5.99V 11.98V 11.98V 5.06V 5.06V
Q1200
IR RS232 Pin Buffer B 0.634V C 0.97V E Gnd
D1000
Speed Up Reset Pin IC1004 C 3.4V A 3.38V
42LH90 Main Board (Back Side) Component Layout
42LH90 MAIN BOARD (Back View)
IC3505
Q705 B E Q704 B E Q703 B E
IC800
C C
IC107
C
2 1 3
IC102 FLASH
IC1202
IC104 IC702 Q105 C
D500
Q1000 Q1001 E
A2 A1 C
C
IC501
E B C
B
A1
IC1201
19 Video
TUNER TU1001 TDVW-H103F
16 SIF
(5V) 4
B C
A2 C E
IC103
Q600 IC703
IC1200
13 DIF 12 DIF +
3
D102
E B 2 1
A1 A2 C
D1223
1
72
IC1003
42LH90 Main (Back Side) Component Voltages IC103
Reset Gen Pin Mstar IC100 [1] Gnd [2] 0V [3] 3.3V RGB (PC) EEPROM
IC104 Pin [1] [2] [3] [4] [5] [6] [7] [8] IC107
3
Pin [1] [2] 1 3 2 [3]
Pin [1] [2] [3] [4] [5] [6] [7] [8]
+3.3V_ST +3.3V_AVDD_MPLL Regulator Gnd 3.29V 5.11V
IC703
+3.3V_ST Pin Regulator [1] 0V [2] 1.8V [3] 3.21V
IC800
SPI Flash Pin [1] [2] [3] [4] [5] [6] [7] [8]
IC1200
Gnd Gnd Gnd Gnd 3.22V 3.22V 0V 3.22V
Power Det Pin Gen [1] Gnd [2] 3.9V [3] 3.28V
IC702
9V Reg Pin to IC1002 [1] 12V [2] Gnd [3] 8.9V For Tuner Voltage 5V IC1003
0.12V 1.13V 3.26V Gnd 0.06V 1.2V 3.27V 3.27V
IC1201 Pin [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] IC1202 Pin [1] [2] [3] [4] [5] [6]
RGB EEPROM Gnd Gnd Gnd Gnd 4.82V 4.82V 4.82V 4.82V RS232 Rx/Tx 3.3V 5.56V 0.02V 0.03V 5.46V 5.5V 5.5V 0V 3.29V 3.24V 0.02V 3.29V 0V 5.5V Gnd 3.29V USB +5V Switch 4.95V Gnd 3.21V 4.95V 0V 4.95V
73
IC3505
Reset Gen Pin for IC3502 [1] 3.3V [2] Gnd [3] 3.22V
Q1001
Tuner Video Pin Buffer B 3.09V C 0V E 3.72V
Q105
PWR On Delay Pin Q2405 B 0V C 1.95V E Gnd
D102
Audio Mute Pin Routing A1 0.047V C 0.089V A2 0V
Q600
Audio Mute Pin Switch B 0.08V C 3.26V E Gnd
D500
Shunt for Pin IC501 A1 3.25V C 3.12V A2 0V
Q703
5V Switch Pin Control B 0.6V C 0.03V E Gnd
D1223
5V Routing Pin for IC1200 A1 0V C 4.82V A2 5.11V
Q704
12V LVDS Pin Switch Control B 0.05V C 0.65V E Gnd
Q705
12V LVDS Pin Switch B 0.65V C 0.0V E Gnd
Q1000
Tuner SIF Pin Buffer B 2.4V C 0V E 3.85V
Main Board X100 and X800 Crystal Checks X100 1.58V
IC100 Microprocessor Crystal
2.56Vp/p 12Mhz Set on or off. Use bottom leg.
1.51V
1.59V IC800 XD Engine Crystal
2.25Vp/p 12Mhz Set on. Use bottom leg.
1.54V
MAIN Board
X800
74
February 2010
LCD DV
42LH90
Main Board X3500 and X1005 Crystal Check 5.34Vp/p 25Mhz Right Leg
X3500
Dimming/Tru-Motion IC3502 Dimming IC Crystal
1.54V
1.57V
3.94Vp/p 25Mhz Set on. Use Left leg.
X1005
IC1005 Tuner Control IC Crystal
1.54V 3.54Vp/p 25Mhz Set on. Use Top leg.
MAIN Board
5.67Vp/p 25Mhz Bottom Leg
1.64V
75
February 2010
LCD DV
42LH90
Main Board LD1000 Function Use LD1000 as a visual aid. This lets you know the PLL (Phase Lock Loop) circuit is working correctly in IC1004. This indicates the Tuner Crystal is Locked to the Reference frequency in IC1004.
Main Board LD1000 Location
76
LD1000 February 2010 LCD DV
42LH90
Main Board Connector P700 to Power Supply Voltage and Diode Check P700 “Main Board" to P201 “SMPS" Odd Pins
Even Pins
Pin
Label
STBY
Run
Diode Check
Pin
23
nc
nc
nc
Open
24
A.DIM
0.47V
1.66V
Open
19
nc
nc
nc
17
24V
0V
15
Gnd
13
P700
STBY
Run
Diode Check
PDIM
0V
2.43V
1.3V
22
Err Out
0V
0V
Open
Open
20
Inv_On
0V
4.65V
2.9V
24V
Open
18
24V
0V
24V
Open
Gnd
Gnd
Gnd
16
Gnd
Gnd
Gnd
Gnd
12V
0V
12V
2.2V
14
12V
0V
12V
2.2V
11
Gnd
Gnd
Gnd
Gnd
12
Gnd
Gnd
Gnd
Gnd
9
5.2V
5.15V
5.15V
1.1V
10
5.2V
5.15V
5.15V
1.1V
7
5.2V
5.15V
5.15V
1.1V
8
5.2V
5.15V
5.15V
1.1V
5
Gnd
Gnd
Gnd
Gnd
6
Gnd
Gnd
Gnd
Gnd
3
Gnd
Gnd
Gnd
Gnd
4
Gnd
Gnd
Gnd
Gnd
1
nc
nc
nc
Open
2
PWR-ON
0V
5V
2.6V
21
1
1
Label 2
2
ADIM Pin 21 Fixed and not used. It is an Open connection on the Inverter Board.
PDIM Pin 24 can vary according to type of signal being processed, OSD Backlight setting. 0.6V 0% to 3.3V 100% and the Intelligent Sensor. Output from the Video Processor IC100.
Diode Mode values taken with all Connectors Removed
77
February 2010
LCD DV
42LH90
Main Board Connector P3500 to the T-CON Voltage and Diode Check P3500 CONNECTOR “Main" to “T-CON“ CN1 Pin
Label
Run
Diode Test
Pin
Label
Diode Mode values taken with all Connectors Removed Run
Diode Test
Pin
Label
Run
Diode Test
1
LVDS 12V
12V
Open
21
LVDS_CH2_B+
1.1V
0.87V
41
Gnd
Gnd
Gnd
2
LVDS 12V
12V
Open
22
LVDS_CH2_B-
1.4V
1.2V
42
OPC-EN
n/c
1.09V
3
LVDS 12V
12V
Open
23
LVDS_CH2_A+
1.1V
1.22V
43
OPC-Out
n/c
Open
4
LVDS 12V
12V
Open
24
LVDS_CH2_A-
1.4V
0.88V
44
*PWM-DIM
n/c
Open
5
n/c
n/c
n/c
25
n/c
n/c
n/c
45
LVDS-Sel
n/c
Open
6
Gnd
Gnd
Gnd
26
Gnd
Gnd
Gnd
46
n/c
n/c
Open
Gnd
Gnd
Gnd
27
LVDS_CH1_E+
7
1.1V
0.87V
47
n/c
n/c
Open
Gnd
Gnd
Gnd
28
LVDS_CH1_E-
8
1.4V
1.23V
48
n/c
n/c
Open
Gnd
Gnd
Gnd
29
LVDS_CH1_D+
9
1.1V
1.23V
49
n/c
n/c
Open
Gnd
Gnd
Gnd
30
LVDS_CH1_D-
10
1.4V
1.23V
50
n/c
n/c
Open
11
LVDS_CH2_E+
1.09V
1.23V
31
Gnd
Gnd
Gnd
51
Gnd
Gnd
Gnd
LVDS_CH2_E-
1.44V
0.875V
32
LVDS_CH1_CLK+
12
1.26V
1.20V
LVDS_CH2_D+
1.09V
1.23V
33
LVDS_CH1_CLK-
13
1.25V
1.2V
14
LVDS_CH2_D-
1.44V
1.23V
34
Gnd
Gnd
Gnd
Gnd
Gnd
Gnd
35
LVDS_CH1_C+
15
1.4V
0.88V
LVDS_CH2_CLK+
1.22V
1.14V
36
LVDS_CH1_C-
16
1.4V
1.22V
LVDS_CH2_CLK-
1.21V
1.25V
37
LVDS_CH1_B+
17
1.2V
1.11V
Gnd
Gnd
Gnd
38
LVDS_CH1_B-
18
1.3V
1.23V
LVDS_CH2_C+
1.13V
1.23V
39
LVDS_CH1_A+
19
1.2V
1.18V
LVDS_CH2_C-
1.4V
0.87V
40
LVDS_CH1_A-
20
1.3V
1.05V
78
PWM-DIM (Pin 44) is Open on the Main Board.
February 2010
1
P3500
LCD DV
42LH90
Main Board Connector P3502 to the T-CON Voltage and Diode Check Diode Mode values taken with all Connectors Removed
P3502 CONNECTOR “Main" to “T-CON“ CN2 Pin
Label
Run
Diode Test
Pin
Label
Run
Diode Test
1
Gnd
Gnd
Gnd
21
LVDS_CH3_D+
1.2V
1.2V
2
Gnd
Gnd
Gnd
22
LVDS_CH3_D-
1.3V
1.23V
3
LVDS_CH4_E+
1.15V
1.18V
23
Gnd
Gnd
Gnd
4
LVDS_CH4_E-
1.4V
1.24V
24
LVDS_CH3_CLK+
1.3V
0.87V
5
LVDS_CH4_D+
1.25V
0.87V
25
LVDS_CH3_CLK-
1.23V
0.87V
6
LVDS_CH4_D-
1.3V
1.12V
26
Gnd
Gnd
Gnd
7
Gnd
Gnd
Gnd
27
LVDS_CH3_C+
1.2V
1.03V
8
LVDS_CH4_CLK+
1.29V
1.22V
28
LVDS_CH3_C-
1.3V
0.87V
9
LVDS_CH4_CLK-
1.3V
1.23V
29
LVDS_CH3_B+
1.2V
0.87V
10
Gnd
Gnd
Gnd
30
LVDS_CH3_B-
1.3V
1.23V
11
LVDS_CH4_C+
1.2V
0.87V
31
LVDS_CH3_A+
1.2V
1.20V
12
LVDS_CH4_C-
1.3V
0.87V
32
LVDS_CH3_A-
1.28V
0.87V
13
LVDS_CH4_B+
1.3V
1.23V
33
Gnd
Gnd
Gnd
14
LVDS_CH4_B-
1.29V
0.87V
34
n/c
n/c
n/c
15
LVDS_CH4_A+
1.25V
1.23V
35
n/c
n/c
n/c
16
LVDS_CH4_A-
1.29V
0.87V
36
n/c
n/c
n/c
17
Gnd
Gnd
Gnd
37
n/c
n/c
n/c
18
Gnd
Gnd
Gnd
38
n/c
n/c
n/c
19
LVDS_CH3_E+
1.18V
1.08V
39
n/c
n/c
n/c
20
LVDS_CH3_E-
1.13V
1.07V
40
n/c
n/c
n/c
41
Gnd
Gnd
Gnd
79
February 2010
P3502
LCD DV
1
42LH90
Main Board Connector P1200 to (Ft. IR/Intelligent Sensor) Voltage and Diode Check P1200 CONNECTOR "MAIN Board" to P101 "Front IR / Intelligent Sensor Board" Pin
Label
STBY
Run
Diode Check
1
SCL
0.57V
3.2V
1.6V
2
SDA
0.57V
3.2V
1.6V
3
Gnd
Gnd
Gnd
Gnd
4
Key1
3.2V
3.2V
1.0V
5
Key2
3.2V
3.2V
1.0V
6
5V_ST
5.1V
5.1V
1.1V
7
Gnd
Gnd
Gnd
Gnd
8
WARM_ST
Gnd
Gnd
Gnd
9
IR
3.5V
3.5V
Open
10
Gnd
Gnd
Gnd
Open
11
3.3V_ST
3.2V
3.2V
0.67V
12
PWR On
0V
3.2V
Open
1
P1200
Diode Mode values taken with all Connectors Removed
80
February 2010
LCD DV
42LH90
Main Board Connector P600 to Speakers Voltage and Diode Check Q400 (Mute) Active Low. Normal 3.3V Collector to Pin 25
Audio B+ 24V Pins 49-52
P600
IC600
Mute Driver Q600 Back of board
Mute Pin 25 Use speaker out to test for defective Audio Amp IC600 Note: (Normal, ½ Audio B+) P400 CONNECTOR "Main" to "Speakers" Pin
LABEL
SBY
Run
Diode Check
1
SPK-R(-)
0V
12V
2.63V
2
SPK-R(+)
0V
12V
2.63V
3
SPK-L(-)
0V
12V
2.63V
4
SPK-L(+)
0V
12V
2.63V
Diode Mode values taken with all Connectors Removed
81
February 2010
LCD DV
42LH90
FRONT (IR, INTELLIGENT SENSOR and MOVING LED) SECTION The Intelligent Sensor and IR board (located on the bottom left as viewed from the rear) contains the IR (Infrared Remote Sensor) and the Intelligent Sensor. This board also connects with the Side Key Board and the Moving LED board which contains the 10 front Power LEDs. The IR board receives it operating B+ via P101 pin 6 (STBY 5V) and pin 11 (3.3V) from connector P1200 on the Main board. The Intelligent Sensor communicates with the Micro/Video Processor IC100 Mstar Chip via clock and data lines SCL1 and SDA1 (AA17 and AA18) arriving on connector P101 from P700 pins 1 and 2 on the Main board. The Front Power LEDs are controlled by these same Clock and Data lines which communicate with the LED Driver IC U1 on the Moving LED board. The IR pulses (5V p/p) P101 pin 9 are sent to P1200 on the Main board and on to the Microprocessor (IC100) via pin C4. The Key board is routed to the IR board via P100 to P102 on the Key 1 and Key 2 lines, (Key 1 pin 1 and Key 2 pin 3). Then out P101 pins 4 and 5 to P1200 on the Main Board. Then to the Microprocessor A4 and B4 lines.
82
February 2010
LCD DV
42LH90
Front Boards (Connections Identified) p/n EBR62127501
Key board p/n EBR62128101
Intelligent Sensor / IR board P101 P100 J1 P102 P100 Moving LED board (Power LEDs) p/n EBR61674001
83
February 2010
LCD DV
42LH90
Front Moving LED Board Identified The Front LED Board (located on the bottom left as viewed from the rear) Contains the front Power LEDs.
Power LEDs
J1 Connector To Intelligent Sensor and IR Board
Pin 1
U1 LED Driver 84
February 2010
LCD DV
42LH90
Front Board Connectors P101 and P2 Voltage and Diode Check P101 CONNECTOR "Front IR / Intelligent Sensor" to P1200 " MAIN Board " Pin
Label
STBY
Run
Diode Check
1
SCL
0.57V
3.2V
Open
2
SDA
0.57V
3.2V
Open
3
Gnd
Gnd
Gnd
Gnd
4
Key1
3.2V
3.2V
Open
5
Key2
3.2V
3.2V
Open
6
ST_5V
5.1V
5.1V
Open
7
Gnd
Gnd
Gnd
Gnd
8
Warm_ST
Gnd
Gnd
Open
9
IR
3.5V
3.5V
Open
10
Gnd
Gnd
Gnd
Gnd
11
3.3V
3.2V
3.2V
Open
12
LED On
0V
3.2V
Open
P2 Connector to “Side Key" P100 Pin
Label
STBY
Run
1
Key 1
3.2V
32V
Diode Check Open
2
Gnd
Gnd
Gnd
Gnd
3
Key 2
3.2V
3.2V
Open
4
Gnd
Gnd
Gnd
Gnd
Diode Mode values taken with all Connectors Removed
85
February 2010
LCD DV
42LH90
Front Board Connector P100 and J1 Voltage and Diode Check P100 CONNECTOR "Front IR / Intelligent Sensor" to J1 "Moving LED Board"
J1 "Moving LED Board" P100 CONNECTOR "Front IR / Intelligent Sensor"
Pin
STBY
Run
Diode Check
Pin
Diode Check
1
5V
5V
Open
1
Open
2
Gnd
Gnd
Gnd
2
Gnd
3
0.59V
4.9V
Open
3
Open
4
Gnd
Gnd
Gnd
4
Gnd
5
0.75V
5V
Open
5
Open
6
Gnd
Gnd
Gnd
6
Gnd
7
*0V
*3.27V
Open
7
Open
8
0V
0V
Open
8
Open
*Pin 7: From Pin 12 of P101 IR board From Pin 12 of P1200 Main board From R196 Main board From Pin GPIO96 of Micro IC100
See P100 Table for Voltages
Pin 7: From Pin 7 of P100
Diode Mode values taken with all Connectors Removed
86
February 2010
LCD DV
42LH90
SIDE KEY BOARD SECTION p/n EBR62127501
SW101 SW103 SW105 SW107 SW100 SW102 SW104 SW106
To Ft Control
P100
P100
87
February 2010
LCD DV
42LH90
Side Key Assembly P100 Voltage and Diode Check
P100 Resistance Measurements with Key pressed. KEY
Pin 1 measured from Gnd
KEY
Pin 3 measured from Gnd
Power
270.5 Ohms
Volume (-)
270.5 Ohms
Input
1.8K Ohms
Volume (+)
1.8K Ohms
Menu
4.8K Ohms
CH (Dn)
4.8K Ohms
Enter
10K Ohms
CH (Up)
10K Ohms
P100 Voltage Measurements with Key pressed.
P100
KEY
Pin 1 measured from Gnd
KEY
Pin 3 measured from Gnd
Power
0.179V
Volume (-)
0.179V
Input
0.906V
Volume (+)
0.906V
Menu
1.65V
CH (Dn)
1.65V
Enter
2.24V
CH (Up)
2.24V
P100 Connector “Side Key" to “IR/Intelligent Sensor Board“ P2 Pin
Label
STBY
Run
Diode Check
1
Key1
3.3V
3.3V
Open
2
Gnd
Gnd
Gnd
Gnd
3
Key2
3.3V
3.3V
Open
4
Gnd
Gnd
Gnd
Gnd
88
February 2010
LCD DV
42LH90
INVISIBLE SPEAKER SECTION The 42LH90 contains the Invisible Speaker system. The Full Range Speakers point downward, so there is no front viewable speaker grill or air ports. Main Speaker (Full Range Frequencies)
Tweeter (High Frequencies)
Full Range p/n EAB58534501
Tweeter p/n EAB58536001
89
February 2010
LCD DV
42LH90
Invisible Speaker System Overview (Tweeters)
Tweeter p/n EAB58536001
Elimination of the conventional speaker. Invisible Speaker has a adhesive surface which adheres to front bezel. WARNING: Removing the Tweeter will destroy the speaker as shown above. The diaphragm/spider is glued to the front bezel. When removing, it will tear.
The front bezel is shown below. Note: the outlined circle is the location for the front adhesive pad on the Invisible Speaker. This prevent the coil from bouncing off the plastic causing vibrations.
Speaker Attachment post
Cabinet works as a diaphragm.
Outlined Circle
90
Invisible Speaker Tweeter shown separately. The Front (down) has an adhesive surface which adheres to front bezel. Note, there is no diaphragm, only voice coil.
February 2010
LCD DV
42LH90
Invisible Speaker System Overview Tweeter p/n EAB58536001 Invisible Speaker Shown separately. Front (to left) has an adhesive surface which adheres to front bezel. Note, there is no Cone (Diaphragm), only voice coil.
Mount Speaker Terminals Spider Speaker Wires
Dust Cap with adhesive
Magnet
Voice Coil Inside Frequency Pass Capacitor
Mount
91
February 2010
LCD DV
42LH90
INTERCONNECT DIAGRAM (11 X 17 FOLDOUT) SECTION
This section shows the 11X17 foldout that’s available in the Paper and Adobe version of the Training Manual. The Adobe version of this Training Manual allows the viewer to zoom in and out making reading of the small text easier. This Power Point shows a graphical representation of the 11 X 17 foldout page so clarity is limited.
92
February 2010
LCD DV
42LH90
42LH90 INTERCONNECT DIAGRAM 16V 3.3V
Pin 16V 56,57,58 3.3V Pin 53,54
TO TFT MODULE
P203 "SMPS" TO CN1 "INVERTER"
12 3 2 IC302 IC301 Processor CN305
D302 blinks 1Hz OK
n/c Q20
IC5 Q21
Q48
IC14
CN306
Q22 ZD304 ZD303 Q23
Q47 Q46 IC6
Q44
n/c
Q25
Q43
IC10
Q41
IC7
Q40
Q29
Q39
Q30
IC8
Q33
Q35
Q34
IC15 1 2 2 2 3
CN4
CN3 IC3
IC1
M1-M4 (27.5V) 680uF 35V
Label
STBY
Run
Diode Check
1
SCL
3.3V
2
SDA
0.57V 0.57V
Open Open
D215
3
Gnd
Gnd
Gnd
D213
L5
CN1
54 321
Q3 Q2
Q5
Q4 D3
M4
C12 680uF 35V
Key1
3.2V
3.2V
5
Key2
3.2V
3.2V
6
5V ST
5.1V
5.1V
Open
7 8
Gnd Warm ST
Gnd 0V
Gnd 0V
Gnd Open
9
IR
3.5V
3.5V
Open
10
Gnd
Gnd
Gnd
Gnd
3.2V
3.2V
Open
+
D2
-
Q9
L2
D7
Q11
L3
-
Q212 Q211 C227 + 680uF 35V -
Q209
Q210
-
D202
D208
159.9V in Stand-By 190 in Run
125V / F1 (12V) 3A
Pin
Label
STBY
Run
14
AGP
0V
0V
1
Ext_VBR_B
0V
Diode Check OPEN
0.33V-3.2V
E 3.3V
( 12V )
1.66V
OPEN
IC201
Gnd 1.1V
-2.4V 20. 5V
D8 16V
GND
GND
GND
GND
9
GND
GND
GND
GND
8
GND
GND
GND
GND
Err Out 1 A.DIM
20 27V D10 14.25 V
U5
INV.ON
7
GND
GND
GND
GND
6
GND
GND
GND
GND
0V
24.0V
0V
Open
3,4,5,6
1.66V
Open
7,8,9,10
0V
4.65V
Open
11,12
Gnd
13,14
2.2V
nc
nc
nc
nc
0V
24V
0.74V
15,16
Gnd Open Open
15,16
Gnd
Gnd
Gnd
Gnd
13,14
12V
0V
12V
0.98V
19
11,12
Gnd
Gnd
Gnd
Gnd
20
2.9V
7,8,9,10
5V
5.15V
5.15V
Open
21
Open
3,4,5,6
Gnd
Gnd
Gnd
Gnd
22
Open
1.6V
23
Open
nc
24
1.3V
26V 16V R702 R701 16V VDD
2
PWR-On
1
0V
nc
4.98V
nc
nc
For Voltages see P201 PDIM Pin 24 can vary according to type of signal being processed and the OSD Backlight setting. 0.6V 0% to 3.3V 100%. Output from the IC100 Video Processor.
ADIM Pin 21 Fixed and not used
P3502
P3500
IC3504 IC3503
P3501
IC3502 TruMotion/ Dimming
T501
E B C 1 2 IC107 Q702 3
IC502
F101
C
IC704
X3500 25Mhz
L726
IC701
IC801 IC105
IC1
Hot Gnd
Q602
L601
IC101 C E B Q100
SW100 IC104 IC702 C 5A 250V
F100
SK100
P600
L607
Q105 IC103
E B 2 1
E Q106 B C 3
Pin Label STBY Run
J1
3.2V Gnd 3.2V Gnd
3.2V Gnd 3.2V Gnd
Diode Check Open Gnd Open Gnd
A1 B C E C A2
L606
L712
IC703
Tuner
IC1000 IC1001 IC1202
IC102
D1000 X1005 25Mhz
IC600 Q600
SK101
Main Power SW
Micro/Video Processor Mstar X100 12Mhz
IC502
IC1203 IC1200 C A1
D1223
TU1001 Tuner TDVW-H103F Q1200 B C E
Analog Video (19) SIF (16) Dig DIF- (13) Dig DIF+ (12) Clock (9) Data (8) Tuner 5V_TU (4) (1)
LED Board Speakers
D1000
D500 A1 A2 Q1000 E C C E C IC1004 IC1201 B B IC501 Q1001
A2 IC1003
IC707
IC708
IC100
D102
Key1 Gnd Key2 Gnd
P101 N/A
IC900
Q102
IC1002
1 2 3 4
IC901
IC800 X800 12Mhz
L718
Q701 E B C
Grayed Out Components are on the Back For Main board component Voltages see PG 3 of Interconnect Diagram
IC2
IC705
L710
IC706 IC501
B E B E B E
C C
SW3500 Not Used IC3505
Q705 Q704 Q703
P700
IC503
P102 "Front IR / LED PWB to P100 Keys
IR Receiver Intelligent Sensor P100
IC3502 Operates at high temperature
D601
P101
Front PWB Assembly P102
42LH90 MAIN BOARD
12V LVDS Pins 1~4
Q706
2.9V
Ext_VBR_B same as (P-DIM)
Q19 through Q50 Note: Each output driver (switch) has a TP to the left and right representing a “V” which indicates a Block of LEDs. V34 represents Pin 23 of CN4 V33 represents Pin 24 of CN4 Grounding these points when the 27.6V supplies are working will cause the entire Block of Backlight LEDs to turn on. (100mA to light one block)
0V 0V
17,18
1
P100
nc
24V
19 17,18
SMPS TEST 2: Jump pin 2 to pin 20 (INV-ON). (Backlights and all voltages should turn on).
IC102
Q601
VIN
nc
P1200
10
1-5
P201
SMPS TEST 1: To Force Power Supply On. Disconnect P700 on Main PWB. Jump pin 7,8,9 or 10 (5V) to pin 2 using a 100Ω resistor. (Test Voltage Outputs 12V, and 24V).
3.15A 250V
Hot Gnd
OPEN
0.47V
-
2.6V
CN2
SMPS Switch Mode Power Supply
Q101
NC
L202
L204
Open
11
C203
L203
3.2V
C3
D207
M1
0V
1.6V
680uF 35V
L201
M2+
C212 680uF 35V
B 2.78V
D201
4.65V
+
nc
nc
2
BD101 Bridge Rectifier
D203
Open
12V LVDS Pins 48~51
D211
0V
L4
1 2
IC3500
ON/OFF
Side (Key) Controls
Q203
Q204
L1 Q1
U10 8) 3.34V 7) 3.09V 6) 3.34V 5) 3.34V
T101
12
D8 Q202
Q205
-
3.3V_ST POWER On/Off
13
M3+
C27 680uF 35V
U5 B+ ( 12V ) C 3.3V
CN1
P203
CN1 "INVERTER" TO P203 "SMPS"
F1 12A/65V 24V
+
Q10
Q12
L1
4
12
ZD3
F2 2A/125V 24V
3.3V
Gnd Open Open
11
+ -
GND
Open
1
680uF 35V
C40
GND
2 U11
P1200 "MAIN” to P101 "Front IR / LED
To Backlights
INVERTER Board 1 2 3
7
Pin Q32
Q36
IC4
GND
1) Gnd 2) Gnd 3) Gnd 4) Gnd
3.2V
12V LVDS Pins 1~4
Q31 IC9
Q37
GND
FL1
0V
Diode Check
-4.9V
D9
UC1
Q28
Q38
To Backlights
(Pin 1) 3.54Vp/p
Q27
Q42
8
Gnd Protect
1) 0V 1 2) 1.19V 2 3 3) 3.3V
GND 6 GND 1-5 0.74V VIN For Voltages see CN1 Table
(Pin 4) 3.48Vp/p
CN307
Q26
9
OPEN OPEN GND GND
10
D7
OPEN
ON/OFF NC GND GND
11
(Pin 6) 3.46Vp/p
Q24
IC13
Q45
12
Gnd 3.3V
IN
Q49
Q19
L2
U12
OPEN
AGP Ext_VBR_B
2 PDIM
21
N
Q50
14 13
24 22
L
D302
3.3V
Diode Check
Label
Diode Check
FL2 Gnd Protect
AC
1.76Vp/p 1.25Vp/p
Pin
Run
FLASH
Y301 (12Mhz)
CN4 27.5V Line on CN4 Pins 1-2 (Out_M3) Pins 13-14 (Out_M3) Pins 16-17 (Out_M3) Pins 26-29 (Out_M3) Pins 31-32 (Out_M1) Pins 43-44 (Out_M1) Pins 46-47 (Out_M1) Pins 58-59 (Out_M1)
STBY
CN4
C744 R721
CN3 27.5V Line on CN3 Pins 1-2 (Out_M2) Pins 13-14 (Out_M2) Pins 16-17 (Out_M2) Pins 26-29 (Out_M2) Pins 31-32 (Out_M4) Pins 43-44 (Out_M4) Pins 46-47 (Out_M4) Pins 58-59 (Out_M4)
Label
23
T-CON P/N EAT60665101 (TFT Driver) VCC
CN5
IC303 2 3 21
Pin
TO TFT MODULE
TO TFT MODULE
INVERTER CN3-CN4 INFO.
Pin 2 -4.9V Pin 4 26V
R704 R705 R706
Pin 59 -4.9V Pin 3,4,5 Pin 57 26V Pin 7,8
P700 "Main" to P201 “SMPS"
P201 “SMPS" to P700 "Main"
42LH90 MAIN (FRONT SIDE) SIMICONDUCTORS IC101 Pin [1] [2] [3] [4] [5] [6] [7] [8] IC105 Pin [1] [2] [3] [4] [5] [6] [7] [8] IC701 Pin [1] [2] [3] [4] [5] [6] [7] [8]
Serial Flash Memory 0.05V 3.2V 2.5V Gnd 0V 0V 3.3V 3.3V HDCP EEPROM
+1.26V_VDDC Regulator 0.8V Gnd 5V 6V 3.2V 1.2V 1.26V 5V
IC708
Pin [1] [2] [3] [4] [5] [6] [7] [8]
IC705
Gnd Gnd 3.29V Gnd 3.3V 3.3V 0V 3.3V +1.8V_DDR Regulator
+3.3V_FE Regulator 0.8V Gnd 5V 7.5V 5V 3.3V 3.3V 2.1V
IC707
Pin [1] [2] [3] [4] [5] [6] [7] [8]
IC704
5V_EXT Memory
IC706 Pin [1] [2] [3] [4] [5] [6] [7] [8]
0V 3.2V 3.2V n/c n/c 1.8V 0.8V Gnd
Pin [1] [2] [3] [4] [5] [6] [7] [8]
+1.8V_MEMC Regulator 0.8V Gnd 4.92V 6.5V 4.8V 1.8V 1.8V 4.8V
Pin [1] [2] [3] [4] [5] [6] [7] [8]
+1.26V_MEMC Regulator Gnd 0.8V 1.26V 1.26V 1.8V 5V 1.26V 5V
Pin [1] [2] [3] [4] [5] [6] [7] [8]
+1.26V_PVSB Regulator 0V 3.39V 3.4V 0V 0V 1.21V 0.8V Gnd
IC1000
0.8V Gnd 12V 9.6V 5V 4.97V 4.97V 1.9V
Pin [1] [2] [3] [4] [5]
+3.3V_PVSB +3.3V_FE 4.94V 4.94V Gnd 3.4V 1.25V
Pin [1] [2] [3] [4] [5]
+5V_TU Tuner 8.92V 1.88V 5.04V 0V Gnd
Pin [1] [2] [3] [4] [5]
SPIF Optical Audio 1.58V 3.2V Gnd 1.61V 3.21V
Pin [1] [2] [3] [4] [5] [6]
USB +5V Switch 4.95V Gnd 3.21V 4.95V 0V 4.95V
IC1001
IC1002
IC1203
+3.3V_Dimming Pin Regulator [1] Gnd [2] 3.3V [3] 5V
Q100
IC3503
+1.8V Reg Pin Dimming [1] 0.58 [2] 1.8V [3] 3.19V
Q106
IC3504
Dimming EEPROM
Q702
IC3500
Pin [1] [2] [3] [4] [5] [6] [7] [8]
W/P IC101 Pin B 0V C 2.5V E Gnd
Reset Gen Pin Mstar IC100 [1] Gnd [2] 0V [3] 3.3V
IC104 Pin [1] [2] [3] [4] [5] [6] [7] [8] IC107
IC702
RGB (PC) EEPROM Gnd Gnd Gnd Gnd 3.22V 3.22V 0V 3.22V
Power Det Pin Gen [1] Gnd [2] 3.9V [3] 3.28V +3.3V_ST +3.3V_AVDD_MPLL Pin Regulator [1] Gnd [2] 3.29V [3] 5.11V
IC703
+3.3V_ST Pin Regulator [1] 0V [2] 1.8V [3] 3.21V
Pin [1] [2] [3] [4] [5] [6] [7] [8]
SPI Flash
IC800 Pin [1] [2] [3] [4] [5] [6] [7] [8]
0.12V 1.13V 3.26V Gnd 0.06V 1.2V 3.27V 3.27V
9V Reg Pin to IC1002 [1] 12V [2] Gnd [3] 8.9V For Tuner Voltage 5V
IC1003
IC1200
IC1201 Pin [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16]
RGB EEPROM Gnd Gnd Gnd Gnd 4.82V 4.82V 4.82V 4.82V
IC1202
IC3505
RS232 Rx/Tx 3.3V 5.56V 0.02V 0.03V 5.46V 5.5V 5.5V 0V 3.29V 3.24V 0.02V 3.29V 0V 5.5V Gnd 3.29V
Q105
Q600
Reset Gen Pin for IC3502 [1] 3.3V [2] Gnd [3] 3.22V PWR On Delay Pin Q2405 B 0V C 1.95V E Gnd Audio Mute Pin Switch B 0.08V C 3.26V E Gnd
Q703
5V Switch Pin Control B 0.6V C 0.03V E Gnd
Q1001
Tuner Video Pin Buffer B 3.09V C 0V E 3.72V
Q704
1st 12V LVDS Pin Switch Control B 0.05V C 0.65V E Gnd
D102
Audio Mute Pin Routing A1 0.047V C 0.089V A2 0V
Q705
2nd 12V LVDS Pin Switch Control B 0.65V C 0.0V E Gnd
D500
Shunt for Pin IC501 A1 3.25V C 3.12V A2 0V
Q1000
Tuner SIF Pin Buffer B 2.4V C 0V E 3.85V
D1223
5V Routing Pin for IC1200 A1 0V C 4.82V A2 5.11V
+5V/12VLVDS Switch 5.1V 0.29V 11.9V 5.99V 11.98V 11.98V 5.06V 5.06V
Q1200
IR RS232 Pin Buffer B 0.634V C 0.97V E Gnd
D1000
Speed Up Reset Pin IC1004 C 3.4V A 3.38V
INV_ON Inverter 0.05V 4.66V Gnd
42LH90 MAIN (BACK SIDE) SIMICONDUCTORS IC103
Pin [1] [2] [3] [4] [5] [6] [7] [8]
S5/S6 Reset Pin Mstar B 0V C 3.28V E 0V
Pin B C E
Gnd Gnd Gnd Gnd 3.3V 3.3V 0V 3.3V
Q706
42LH90 LVDS P3500 WAVEFORMS
Pin 11
Pin 12
Pin 13
Pin 14
Pin 16
Pin 17
Pin 19
Pin 20
Pin 21
Pin 22
Pin 23
Pin 24
Pin 27
Pin 28
Pin 29
Pin 33
Pin 35
Pin 30
Pin 37
Pin 32
Pin 38
Pin 39
Pin 40
Pin 36
42LH90 P3500 LVDS CABLE WAVEFORMS: Waveforms taken using SMTP Color Bar input. All readings give the Scale 10mV and Time Base related to scope settings. Top waveform in each image gives a slower rate, 2us per division. Outlined area is shown in the bottom waveform at 500ns per division time base.
42LH90 LVDS P3502 WAVEFORMS
Pin 3
Pin 4
Pin 5
Pin 6
Pin 8
Pin 9
Pin 11
Pin 12
Pin 13
Pin 14
Pin 15
Pin 16
Pin 19
Pin 20
Pin 21
Pin 22
Pin 24
Pin 25
Pin 27
Pin 28
Pin 29
Pin 30
Pin 31
Pin 32
42LH90 P3502 LVDS CABLE WAVEFORMS: Waveforms taken using SMTP Color Bar input. All readings give the Scale 10mV and Time Base related to scope settings. Top waveform in each image gives a slower rate, 2us per division. Outlined area is shown in the bottom waveform at 500ns per division time base.
42LH90 Direct View LCD
This concludes the 42LH90 training session.
