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LCD TELEVISION




LC-37FB32
CONTENTS


Safety precautions...................................................................................... 1
Alignment instructions ................................................................................ 3
Method of software upgrading...............................................................................
8
Working principle analysis of the unit...............................................................14
Block diagram.............................................................................................15
IC block diagram.........................................................................................16
Wiring diagram ........................................................................................ 27
Identification criteria for the bright spot and dark spot of the LCD screen.............. 28
Troubleshooting guide ................................................................................ 29
Schematic diagram.................................................................................... 38
APPENDIX: Exploded View
Attention: This service manual is only for service personnel to take reference with. Before
servicing please read the following points carefully.

Safety precautions
1. Instructions
Be sure to switch off the power supply before replacing or welding any components or
inserting/plugging in connection wire Anti static measures to be taken (throughout the entire
production process!):
a) Do not touch here and there by hand at will;
b) Be sure to use anti static electric iron;
c) It's a must for the welder to wear anti static gloves.
Please refer to the detailed list before replacing components that have special safety requirements.
Do not change the specs and type at will.

2. Points for attention in servicing of LCD
2.1 Screens are different from one model to another and therefore not interchangeable. Be sure to
use the screen of the original model for replacement.
2.2 The operation voltage of LCD screen is 700-825V. Be sure to take proper measures in
protecting yourself and the machine when testing the system in the course of normal operation or
right after the power is switched off. Please do not touch the circuit or the metal part of the module
that is in operation mode. Relevant operation is possible only one minute after the power is
switched off.
2.3 Do not use any adapter that is not identical with the TV set. Otherwise it will cause fire or
damage to the set.
2.4 Never operate the set or do any installation work in bad environment such as wet bathroom,
laundry, kitchen, or nearby fire source, heating equipment and devices or exposure to sunlight etc.
Otherwise bad effect will result.
2.5 If any foreign substance such as water, liquid, metal slices or other matters happens to fall into
the module, be sure to cut the power off immediately and do not move anything on the module lest it
should cause fire or electric shock due to contact with the high voltage or short circuit.
2.6 Should there be smoke, abnormal smell or sound from the module, please shut the power off at
once. Likewise, if the screen is not working after the power is on or in the course of operation, the
power must be cut off immediately and no more operation is allowed under the same condition.
2.7 Do not pull out or plug in the connection wire when the module is in operation or just after the
power is off because in this case relatively high voltage still remains in the capacitor of the driving
circuit. Please wait at least one minute before the pulling out or plugging in the connection wire.
2.8 When operating or installing LCD please don't subject the LCD components to bending, twisting
or extrusion, collision lest mishap should result.
2.9 As most of the circuitry in LCD TV set is composed of CMOS integrated circuits, it's necessary
to pay attention to anti statics. Before servicing LCD TV make sure to take anti static measure and
ensure full grounding for all the parts that have to be grounded.
2.10 There are lots of connection wires between parts behind the LCD screen. When servicing or
moving the set please take care not to touch or scratch them. Once they are damaged the screen

1
would be unable to work and no way to get it repaired.
If the connection wires, connectors or components fixed by the thermotropic glue need to disengage
when service, please soak the thermotropic glue into the alhocol and then pull them out in case of
damage.
2.11 Special care must be taken in transporting or handling it. Exquisite shock vibration may lead to
breakage of screen glass or damage to driving circuit. Therefore it must be packed in a strong case
before the transportation or handling.
2.12 For the storage make sure to put it in a place where the environment can be controlled so as to
prevent the temperature and humidity from exceeding the limits as specified in the manual. For
prolonged storage, it is necessary to house it in an anti-moisture bag and put them altogether in one
place. The ambient conditions are tabulated as follows:
Temperature Scope for operation 0 ~ +50 oC
Scope for storage -20 ~ +60 oC
Humidity Scope for operation 20% ~ 85%
Scope for storage 10% ~ 90%
2.13 Display of a fixed picture for a long time may result in appearance of picture residue on the
screen, as commonly called "ghost shadow". The extent of the residual picture varies with the
maker of LCD screen. This phenomenon doesn't represent failure. This "ghost shadow" may remain
in the picture for a period of time (several minutes). But when operating it please avoid displaying
still picture in high brightness for a long time.

3. Points for attention during installation
3.1 The front panel of LCD screen is of glass. When installing it please make sure to put it in place.
3.2 For service or installation it's necessary to use specified screw lest it should damage the screen.
3.3 Be sure to take anti dust measures. Any foreign substance that happens to fall down between
the screen and the glass will affect the receiving and viewing effect
3.4 When dismantling or mounting the protective partition plate that is used for anti vibration and
insulation please take care to keep it in intactness so as to avoid hidden trouble.
3.5 Be sure to protect the cabinet from damage or scratch during service, dismantling or mounting.




2
Alignment instructions
1. Test equipment
PM5515 (video signal generator)
VG-849 (YUV, VGA, HDMI signal generator)
CA210 (white balancer)
2. The alignment flow chart (see below figure)

Check DDC and FLASH



To produce digital board and analog board



All testing



Adjust white balance



Connect with central signal source, then check each function of TV such as
station missing, analog control etc., check the output of headphone and speaker



Input AV/SVIDEO signal, then check each function of all the terminals



Input HD signal (format), then check each function of the terminal



Input VGA, HDMI signal, check if the display is normal, check each
function such as analog control etc., check horizontal /vertical center etc.




Preset ex-factory



Check the accessories and pack them in box


Fig-1 adjustment flow-chart


3. Description of adjustment
3.1 Unit adjustment
Connect the digital board, analog board, video processing board, button board and remote control
receiver board according to the wiring diagram 203-L27FB18-01JL or 203-L32FB18-01JL. Connect
with power and observe the display.
Method for using factory menu: press "VOL" button to decrease the volume to 0, then press"9876"
to enter level one factory menu. Press "CH+" and "CH-" to select adjustment page, then press "OK"
3
to access. Press "CH+" and "CH-" to move cursor up and down, when the cursor stays on a certain
adjustment item, press "VOL-" and "VOL+" to adjust. Press "MENU" exit to the level one factory
menu; press "EXIT" to exit from the factory menu at any situation.
Note: channel switch isn't available at adjustment menu, only after return to level one factory menu,
you can switch channel.
3.2 adjustment of white balance
3.2.1 input 16 level gray-scale signal from VG849 to HDMI channel (TMIING: select a support
format of HDMI), enter white balance adjustment page of factory menu, select cool color
temperature of item, fixed WBGG_HDMI to 50H, adjust WBRG_HDMI, WBBG_HDMI, let the color
coordinate of third level on the right be (270,283) at 400nits; fixed WBBO_HDMI to 50H, adjust
WBRO_HDMI, WBGO_HDMI, let the color coordinate of third level on the left be (270,283) at 5nits.
The brightness of 400nits and 5nits may obtain by adjusting the contrast and brightness of menu.
3.2.2 input 16 level gray-scale signal from VG849 to AV channel (TMIING:968), enter white balance
adjustment page of factory menu, select cool color temperature of item, fixed WBGG_NTSC to 50H,
adjust WBRG_NTSC, WBBG_ NTSC, let the color coordinate of third level on the right be (270,283)
at 400nits; fixed WBBO_ NTSC to 50H, adjust WBRO_ NTSC, WBGO_ NTSC, let the color
coordinate of third level on the left be (270,283) at 5nits. The brightness of 400nits and 5nits may
obtain by adjusting the contrast and brightness of menu.
3.2.3 input 16 level gray-scale signal from VG849 to VGA channel (TMIING: select a support format
of VGA), enter white balance adjustment page of factory menu, select cool color temperature of
item, fixed WBGG_VGA to 128, adjust WBRG_ VGA, WBBG_VGA, let the color coordinate of third
level on the right be (270,283) at 400nits; fixed WBGO_VGA to 128, adjust WBRO_VGA,
WBBO_VGA, let the color coordinate of third level on the left be (270,283) at 5nits. The brightness
of 400nits and 5nits may obtain by adjusting the contrast and brightness of menu.
3.2.4 input 16 level gray-scale signal of 480I from VG849 to YPbPr channel, enter white balance
adjustment page of factory menu, select cool color temperature of item, fixed WBRG_YPbPr480I,
WBGG_YPbPr480I, WBBG_YPbPr480I to 128, and WBRO_YPbPr480I to 128, adjust
WBRO_YPbPr480I, WBBO_YPbPr480I, let the color coordinate of third level on the left be (270,283)
at 5nits. The brightness of 5nits may obtain by adjusting the contrast and brightness of menu.
Input format signals separately list on table 1, repeat the operation above until the white balance
pass muster.
Note: the white balance adjustment of VGA and YPBPR must be done at the situation that the white
balance adjustment of HDMI is accurate.
4 Performance check
4.1 TV function
Connect RF-TV terminal to the central signal source, enter the setup menu auto search, check if
there is station skipping, the output of earphone and speaker, the picture are normal.
4.2 AV/S-VIDEO terminal
Input AV/S signal, check if the picture and sound are normal.
4.3 YPbPr/YCbCr terminal
Input YUV signal (VG-849 signal generator), separate input YUV format signal of table 1 and check
if the picture and sound are normal.
Table 1 YUV signal format
No H-frequency (KHz) V-frequency (KHz) Signal
1 15.734 59.94 SDTV 480i

4
2 31.469 59.94 HDTV 480p
3 44.955 59.94 HDTV 720p
4 33.716 59.94 HDTV 1080i


4.4 VGA terminal
Input VGA signal (VG-849 signal generator), separate input VGA format signal of table 2 and check
if the picture and sound are normal. If the image is deflection of the H-field, select manual correction
of Advanced Video Menu.
4.5 HDMI terminal
HDMI signal format receives the three high-definition signals: 480I, 480P, 720P/60Hz, 1080I/60Hz,
except for the table 2 signal. Check if the image (contain HDCP ON and OFF) and sound are
normal.
Table 2 VGA signal format
Point clock pulse
No Resolution H-frequency(kHz) V-frenquency(Hz) Remark
frenquency(MHz)
1 720 X 400 31.469 70.086 28.322 IBM
2 640 X 480 31.469 59.94 25.175 IBM
3 640 X 480 37.861 72.809 31.5 VESA
4 640 X 480 37.5 75 31.5 VESA
5 640 X 480 43.269 85.008 36 VESA
6 800 X 600 35.156 56.25 36 VESA
7 800 X 600 37.879 60.317 40 VESA
8 800 X 600 48.077 72.188 50 VESA
9 800 X 600 46.875 75 49.5 VESA
10 800 X 600 53.674 85.061 56.25 VESA
11 1024 X 768 48.363 60.004 65 VESA
12 1024 X 768 56.476 70.069 75 VESA
13 1024 X 768 60.023 75.029 78.75 VESA


5 Ex-factory setting of user menu
1) Select TV channel, volume: 25
2) Video menu, Picture Mode: Nature, Aspect Ratio: Wide
3) Video menu, Advanced Video Menu:
Noise Reduction----Spatial: On
Noise Reduction----Speckle: Off
Noise Reduction----Temporal: On
Sharpness: 0
Tine: 50
Color Temperature: Cool
Skin Tome: White
Auto Contrast Enhancement: Off
Black Bar Detection: Off
3D Y/C: On
4) Audio menu, Sound Mode: News, Balance: 31, Earphone Vo1:31
5
Digital Audio Output: AC-3, MTS: Mono
5) Setup menu, Tuning Band: Air
6) Feature menu, Sleep Timer: Off, Menu Language: English
Note: Except for Color Temperature of Cool, the Advanced Video Menu of YPBPR/YCBCR and
VGA channels sets according to the adjustment of factory.

Trouble shooting
Before servicing please check to find the possible causes of the troubles according to the table
below.
1.Antenna(signal):
Picture is out of focus or jumping Bad status in signal receiving
Poor signal
Check if there are failures with the electrical connector or
the antenna.
Check if the antenna is properly connected.
Fringe in picture Check if the antenna is correctly oriented.
Maybe there is electric wave reflected from hilltop or
building.
Picture is interfered by stripe Possibly due to interference from automobile, train, high
shaped bright spots voltage transmission line, neon lamp etc.
Maybe there is interference between antenna and power
supply line. Please try to separate them in a longer
distance.
Maybe the shielded-layer of signal wire is not connected
properly to the connector.
There appear streaks or light color Check if interfered by other equipment and if interfered
on the screen possibly by the equipment like transmitting antenna, non
professional radio station and cellular phone.

2.TV set:
Symptoms Possible cause
Unable to switch the power on Check to see if the power plug has been inserted
properly into the socket.
No picture and sound Check to see if the power supply of liquid crystal TV has
been switched on. ( as can be indicated by the red LED
at the front of the TV set)
See if it's receiving the signal that is transmitted from
other source than the station
Check if it's connected to the wrong terminal or if the
input mode is correct.
Check if the signal cable connection between video
frequency source and the liquid crystal TV set is correct.
Deterioration of color phase or Check if all the picture setups have been corrected.
color tone

6
Symptoms Possible cause
Screen position or size is not Check is the screen position and size is correctly set up.
proper
Picture is twisted and deformed Check to see if the picture-frame ratio is properly set up.
Picture color changed or colorless Check the "Component" or "RGB" settings of the liquid
crystal TV set and make proper adjustment according to
the signal types.
Picture too bright and there is Check if the contrast setting is too high.
distortion in the brightest area Possibly the output quality of DVD broadcaster is set too
high.
It maybe also due to improper terminal connection of the
video frequency signal in a certain position of the
system.
Picture is whitish or too bright in Check if the setting for the brightness is too high
the darkest area of the picture Possibly the brightness grade of DVD player
(broadcaster) is set too high.
No picture or signal produced from Check if the cable is disconnected.
the displayer if "XXX in search" Check if it's connected to the proper terminal or if the
appears. input mode is correct.
There appears an indication - Check if the TV set can receive input signal. The signal is
"outside the receivable scope) not correctly identified and VGA format is beyond the
specified scope.
Remote control cannot work Check if the batteries are installed in the reverse order.
properly Check if the battery is effective.
Check the distance or angle from the monitor.
Check if there is any obstruct between the remote control
and the TV set.
Check if the remote control signal- receiving window is
exposed to strong fluorescence.
No picture and sound, but only Check if the antenna cable is correctly connected, or if it
hash. has received the video signal correctly.
Blur picture Check if the antenna cable is correctly connected.
Of if it has received the right video signal.
No sound Check if the "mute" audio frequency setting is selected.
Check if the sound volume is set to minimum.
Make sure the earphone is not connected.
Check if the cable connection is loose.
When playing VHS picture search When being played or in pause VHS picture search tape
tape, there are lines at the top or sometimes can't provide stable picture, which may lead
bottom of the picture. to incorrect display of the liquid crystal TV, In this case
please press "auto" key on the remote control so as to
enable the liquid crystal TV set to recheck the signal and
then to display correct picture signal



7
Method of software upgrading
1. Connect RS-232 cable to computer and TV set. The cable must be a female to female RS-232
cable, and the line is TXD to RXD and RXD to TXD cross-link. It's popular for PC to PC
connection.




2. If the computer has no RS-232 serial port(e.g. Notebook PC),you needs a additional USB to serial
port cable.




8
3. Copy the update tools (iDev.exe) to the path you want to do it, and double click it.




4. Select "setup" menu.




5. Confirm the Serial port is right. Base on the port which using for update. And set the band rate to
115200 (default).




9
6. Select the "Image path" menu.




7. Confirm it's the right file.




8. If it's not right(Maybe you didn't select it before),click the "..."button to select "*.ecc" file. Sometimes
the image file you got it will be "*.rar "or "*.zip" zip file, needs unzip it first.




10
9. You also can click the setup button to select and config, but please don't select the red
one(update boot sector).




10. Then click the "down" button.




11
11. You can see the "waiting" window.




12. Then power (off then) on the TV set.




13. After download, it will be burning.




12
14. Last it will be finished




15. Press the (IR/ locate keypad) power key and holding for several second to force power off TV set,
then power on again. It would be ok now. If it's failure you can try once again.




13
Working principle analysis of the unit
1. NTSC signal flow:
Antenna reception NTSC signal send to the integrative tuner FQD1236, which contains HF and IF
amplifier circuit and video decoding circuit. It is controlled by main IC ZR39660 (inside CPU)
through I2C bus. The NTSC signal via frequency tuning, HF amplification, IF amplification, system
switching and decoding, output video signal TV-CVBS of 1Vpp and sound IF signal (SIF).
TV-CVBS and AV1-CVBS, AV2-CVBS input from AV terminal, via switch IC HEF4052 to output
signal, one way send to ZR39660 for VEDIO DECODER, DEINTERLACE and SCALER, then send
to LVDS level drive for LCD screen, another way is output through AV output socket as AV OUT.
The sound IF (SIF) is fed into demodulation IC CAS220, via decoding and A/D conversion, it is fed
into ZR39660 for analog control in the format of I2S. ZR39660 outputs audio data of I2S format, it is
fed into audio D/A converter IC CS4344, output analog L/R signal. The L/R signal and sound signal
of PC/YPRPB via diverter switch HEF4052BT, send to R2S15900SP (sound processing and volume
control). Select right/left sound channel, their send to digital sound amplifier TPA3001 amplify, then
send to speaker.
2. ATSC signal flow:
Antenna reception ATSC signal send to tuner FQD1236, after frequency tuning, HF amplification, IF
amplification and SAW FILTER, output IF signal to demodulation chip CAS220, via VSB or QAM
demodulation, Sound stereo decoder, fed to ZR39660 for information source decoding in the format
of standard serial TS stream.
HD video signal via decoding to A/D conversion and OSD superposition, at last send to LVDS drive
level for PDP panel.
HD audio signal, via decoder built-in ZR39660, resumed to multi- channel sound of Dolby AC-3, at
the same time output data stream of I2S format and S/PDIF data stream. Audio data of I2S format is
fed to audio D/A conversion chip CS4344 to output analog L/R signal. S/PDIF data stream directly
output from optical fiber interface.
3. PC/YPrPb signal flow
PC and two YPBPR signal via matched resistance, it a-c couple to video switch SN74CBT3257CDR,
via switching to selected signal to Triple Video A/D Converter MST9883 A/D conversion. Send
B/G/B of 24 bit to main IC ZR39660 digital decode, image scale and OSD superposition, then send
to LVDS level drive for LCD screen.
Sound signal (PC, YPrPb) via switch diverter HEF4052BT to output signal, it send to R2S15900SP
(sound processing and volume control) switch of audio. Select right/left sound channel, their send to
digital sound amplifier TPA3001 amplify, then send to speaker.
4. HDMI signal flow
HDMI video signal is directly fed to main IC ZR39660 (with HDCP function of HDMI) digital decode,
image scale and OSD superposition, then output LVDS drive level for screen.
HDMI audio signal, via decoder built-in ZR39660,output data stream of I2S format and S/PDIF data
stream at the same time. Audio data of I2S format is fed to audio D/A conversion chip CS4344 to
output analog L/R signal. S/PDIF data stream directly output from optical fiber interface.




14
Block diagram

1 2 3 4 5 6




HDMI1

HDMI2
M29W320E 2X16MX16
DVI AUDIO
YPBPR1 AUDIO
YPBPR2 AUDIO
YPBPR1
YPbPr MST9883 FLASH DDRAM
D
YPBPR2
SN3257C HDMI Switch D




24-BIT Data
HS,VS,CLK




Panel
LVDS

SN3253C
Digital IF ZR39660
C
TUNER
FQD1236 MK5
CAS220CS BGA400 AV_OUT C
Analog SIF
CVBS_TV




CVBS1


CVBS2 HEF4052BT IIS IN
S_Y TS
S_C

B
CVBS,Y/C B




IIS OUT
D/A CS4344



Loudspeaker
TPA3008D2

AV1 AUDIO

A
R2S15900SP Earphone A
NJW1109
Title
AV2 AUDIO
LC-27FB32 D_HDMI

1 2 3 4 5 6




15
IC block diagram
1. ZR39140




16
Pin descriptions of ZR39660:
(1) Serial Transport Input Port
T4: MPEG Transport Port Input Clock
T3: MPEG Transport Input Data
U3: MPEG Transport Input Frame
Y1: MPEG Transport Input Valid

(2) HDMI Input
D1,E3,F3,E2,F2,E1: HDMI Differential Data Pairs
D2,C1: HDMI Differential Clock Pair
C3: HDMI Serial Clock
B2: HDMI Serial Data
A1: HDMI Hot Plug Detect
D3: HDMI Current Set

(3) NTSC/PAL Analog Input Port
W2:Video Front End Luminance In
Y3:Video Front End Chroma In
W3:Video Front End Common Mode Reference

(4) Analog Video Output
K18:Composite Data Output (CVBS)
J20:Blue/Pb Pixel Data Output
J18:Green/Y Pixel Data Output
J19:Red/Pr Pixel Data Output

(5) Audio I/O
R2:Audio Clock
R3:Bit Clock
P3:Left/Right Channel Selector
U2:Serial Audio Data Input
T2:Serial Audio Data Output
V1:IEC958 Format Out

(6) LVDS Panel Interface
B20,C19: Output Clock Pair
E18,F17: Output Data Pairs 0
C20,D19: Output Data Pairs 1
F18,G17: Output Data Pairs 2
D20,E19: Output Data Pairs 3
E20,F19: Output Data Pairs 4
H18,G18: Output Data Pairs 5
F20,G19: Output Data Pairs 6
G20,H19: Output Data Pairs 7
D18 : External Resistor Connection
17
(7) UART and I2C Interface
N1: UART 0 Transmit
P1: UART 0 Receive
R1:I2C Compatible Clock 0
P2:I2C Compatible Data 0
M3:I2C Compatible Clock 1
M2:I2C Compatible Data 1

(8) Miscellaneous
M4, N3: Two pins required to support the 24.576 MHz crystal
N5: Power On Reset
L4: Infrared Receive

2. CAS220/CS
The CAS-220/CSO is a multi-standard demodulator and decoder for terrestrial and digital cable TV
reception. It is designed to support 8-VSB (Vestigial Side Band) in full compliance with ATSC Digital
Television Standards, ITU-T J.83 Annex B, and OpenCableTM Out-of-Band Signaling. The
CAS-220/CSO also demodulates analog BTSC and Korea A2 sound.
Its basic function is to recover the digital data encoded into the broadcast signal, which includes
video and sound program information and ancillary data service.




18
Pin configuration of CAS220/CS:




Pin descriptions of CAS220/CS:
61: RESET_N
79, 80 oscillator
13 Select I2C address
16: I2C data for host communication with the tuner
18: I2C clock to the tuner
19: I2C clock from host
20: I2C data from/to host
93,94: Differential input for IF
96,97: Differential input for SIF
63: Digital Sound Word select (L/R select)
65: Digital Sound Serial data output
66: Digital Sound Serial clock.
17,30,46,62,74,82,84: Power Supply 3.3V
5,9,22,37,53,69,75,78,86,87,99: Power Supply 1.8V
6,7,15,23,33,35,45,55,60,70,73,76,77,81,83,85,88,91,92,95,98: Ground




19
3. MST9883

MST9883 is a Triple Video A/D Converter with Clamps & Pixel Clock Synthesizer. The triple ADC
support 12 - 110 MHz Sampling Rate. It integrated 5-bit pixel clock phase adjustment for precise
sample timing control. It's Output support 4:2:2 Format Mode and it can Pin Compatible with
AD9883A.
Block diagram of MST9883 is flow:




20
Pin configuration of MST9883:




Pin descriptions of MST9883:
54: Red analog input
48: Green analog input
43: Blue analog input
49: Sync on Green analog input
38: External Clamp Input
30: Horizontal SYNC Input
31: Vertical SYNC Input
29: Hold PLL Frequency, do not track HSYNC
56: Serial Interface clock
57: Serial Interface data pin
55: Serial interface address pin
70-77: Red output data
2-9: Green output data
12-19: Blue output data
67: Output data clock
66: HSYNC output
64: VSYNC output
39,42,45,46,51,52,59,62: Analog Power
21
26,27,34,35: PLL Power
11,22, 23, 69,78,79: Digital Output Power
1,10,20,21,24,25,28,32,36,40,41,44,47,50,53,60,61,63,68,80:Ground

4. R2S15900SP
R2S15900SP is an audio signal processor. It has MUTE and Volume/Tone control. It can support 5
input selector.




Pin descriptions of R2S15900SP:
2,27: AV1 AUDIO INPUT L/R
3,26: AV2 AUDIO INPUT L/R
4,25: DTV AUDIO INPUT L/R
5,24: EAR PHONE L/R
6,23: AV OUT L/R
11,19: AUDIO OUTPUT L/R
17,18:I2C SDA/SCL
28: Power Supply
12: Ground

5. TAP3008D2
FEATURES
10-W/Channel Into an 16-W Load From a 17-V Supply
Up to 92% Efficient, Class-D Operation Eliminates Need For Heatsinks
8.5-V to 18-V Single-Supply Operation
Four Selectable, Fixed Gain Settings
Differential Inputs Minimizes Common-Mode Noise

22
Space-Saving, Thermally Enhanced PowerPADTM Packaging
Thermal and Short-Circuit Protection With Auto Recovery Option
Pinout Similar to TPA3000D Family


DESCRIPTION
The TPA3008D2 is a 10-W (per channel) efficient, class-D audio amplifier for driving bridged-tied stereo
speakers. The TPA3008D2 can drive stereo speakers as low as 8 W. The high efficiency of the TPA3008D2
eliminates the need for external heat sinks when playing music.
The gain of the amplifier is controlled by two gain select pins. The gain selections are 15.3, 21.2, 27.2, and
31.8 dB.
The outputs are fully protected against shorts to GND, VCC, and output-to-output shorts. A fault ter-minal
allows short-circuit fault reporting and automatic recovery. Thermal protection ensures that the maximum
junction temperature is not exceeded.




23
24
25
26
Wiring diagram




27
Identification criteria for the bright spot and dark spot of the LCD screen

Quantity allowed Distance between two spots
Category Criteria
15" 20" 22" 30" 40" 15" 20" 22" 30" 40"
One single
5 2 5 2 3
spot
Bright Two
15mm
spot neighboring 2 1 2 1 1
spots
Total No. 5 2 5 2 3
15mm
One single
6 7 5 4 10
spot
Dark Two
10mm 5mm
spots neighboring 2 2 2 1 5
spots
Total No. 6 7 5 4 10
Total defected point 8 7 5 4 /



Notes:
1. Definition of defected point (bright spot, dark spot): It is identified as a defected point if its area
exceeds 1/2 of a single picture element (R, G, B).
2. Definition of bright spot: It is identified as a bright spot if it is bright in the state of dark field and its
bright size remains unchanged
3. Definition of dark spot: It is identified as a dark spot if it is dark in the state of white field and its
dark size remains unchanged
4. Definition of two neighboring points: Defects of a group of picture elements (RB, RG, GB).




28
Troubleshooting guide


Begin




A red indicator No Check power board , button board and power
lights? cord


Yes, turn the unit on


A blue indicator Check if the pin1 of X602 in data processing
No
lights? board is high level(+5V)? check V660/V661.


Yes

Check if the crystal in data processing board
Display picture? No starts, DDR clock is correct?



Yes
Check the signal inputted from the channel to
If the picture of each channel
No pin IC or IC and its peripheral circuit or the
is normal?
output of LVDS is normal


Check the signal inputted from the channel to
If the sound of each channel is No pin IC is normal or IC(R2S15900/TPA3001)
normal?
and its periphery is normal



(1) abnormal picture
a) Failure with resistor rows R839~R844 of image processing board, which may lead to lack of
color or color splash.
b) Failure with resistor rows R825~R830 of image processing board, which may lead to lack of
color or color splash.
c) A certain differential wire pair of LVDS of XA50 or X803(RX0+/-, RX1+/-, RX2+/-, RX3+/-)is
abnormal, which may lead to lack of color or color splash.
d) Failure with resistor rows RA18~RA25, which may lead to loss of corresponding color from
the gray degree corresponding to the picture of channel HDMI.
e) Failure with NB07,NA51 and their peripheral circuit, which may lead to picture abnormal of
PC, YPrPb and YCrCb.
f) Failure with N104, which may lead to picture abnormal of TV, AV1, AV2, S-VIDEO.
g) Failure with N803/N805/N806, which may lead to picture abnormal in all channels.
29
(2) no picture, no sound

No picture, no sound




Check the color of indicator
light
Red Blue



Check the power Check the output voltage of
board sockets X601~X604/X606/X608
Yes
No

No sound No picture Power board problem




Refer to (3) checking Refer to (4) checking
procedure procedure

(3) with picture but no sound

With picture but no sound




Check if the voltage of sound amplifier
of X106 in analog board is normal?

No
Yes


Check if the pin5, pin11 of Check the power board
N111 inputs signals

Yes No



Check N111 and their Check N103/NB05 and
peripheral circuit their peripheral circuit




30
(4) with sound but no picture

With sound but no picture




Display OSD MENU?


Yes No


Display LOGO? If pin5 of X602 (IRR) has signal?

Yes No



If there is no picture Check if the crystal in data processing board starts,
in all channels? DDR clock and DDR SDRAM are normal?

Yes No



Check N108 and Refer to (6), (7), (8), (9), (10),
its peripheral (11), (12) checking procedure
circuit

Yes No



Refer to (5) checking Check N801, N802, DDR
procedure and their peripheral circuit
and power supply




31
(5) Check image processing board


Check the power supply
of N803


Yes No



Check if pin20, 21, 27, Check if the power supply of
30 of X801is high level L801/L802 are normal


Yes No



Check if pin3, 5, 26 of N806 Check the peripheral and power supply of
output H/V-SYNC and clock N801, N802, DDR of data board


No Yes



Check the peripheral and power Check if pin34, 65, 66 of N803 output
supply of N806 H/V-SYNC and clock


No Yes



Check the peripheral and Check the peripheral and
power supply of N803 power supply of N805




Note: please make sure that the data of FLASH N804 is correct before checking the image
processing board.




32
(6) AV no picture

Check if C136 and C137
input signals?


Yes No



Check if pin13 of N104 Check N105/N106 and the circuit
outputs signals? from AV terminal to N104


Yes No



Check the periphery circuit Check N104 and its
from XC02 to N801 periphery circuit




(7) S-terminal no picture

Check if C105 and C138
input signals?


Yes No



Check if pin13/3 of N104 Check N108 and the circuit
outputs signals? from S-terminal to N104


Yes No



Check the periphery circuit Check N104 and its
from XC02 to N801 periphery circuit




33
(8) NTSC channel no picture

Check if pin11 of TUNER226
output signals?


Yes No



Check if pin13 of N104 Check TUNER226 power supply
outputs signals? and the peripheral circuit.


Yes No



Check the periphery circuit Check N104 and its
from XC02 to N801 periphery circuit



(9) ATSC channel no picture

Check if pin6/7 of TUNER226
output signals?


Yes No



Check if the crystal of Check TUNER226 power supply
N228 (20MHz) is normal? and the peripheral circuit.


Yes No



Check the clock signal of Check G226, N228 and
each pin of XC01 periphery circuit



Note :
The I2C bus line control of TUNER is switch through the bus line of N228, so after checking the power
supply and peripheral circuit of TUNER226, it is still no picture in NTSC and ATSC channel, please
check N228 emphatically.




34
(10) YprPb or Ycrcb channel no picture

Check if pin4/7/9 of NB07
output signals?


Yes No



Check if pin64/66/67 of Check if pin4/7/9 of NB08 output
NA51 are normal? signals?

Yes No Yes No



Check resistor Check NA51 Check NB01/NB02 Check NB07
rows RA63~ and peripheral and the circuit from and peripheral
RA68 circuit. X807/X808 to N808 circuit.




(11) D-sub channel no picture

Check if pin4/7/9 of NB07
output signals?


Yes No



Check if pin64/66/67 of Check NB03/NB04
NA51 are normal? and the circuit from
X807/X808 to N808
Yes No



Check resistor Check NA51
rows RA63~ and peripheral
RA68 circuit.




35
(12) HDMI channel no picture


Check DETECT NA04 and its
peripheral circuit?


Yes No



Check if signals of Check the connection to HDMI
RA18~RA25 are normal? socket, NA04 and its peripheral
circuit
Yes

Check N801 and its
peripheral circuit


Note: N801 embeds FLASH, which stores DDC and HDCP information of HDMI, so make sure the
connection between HDMI socket/interface and the bus line is well- going, the picture will display.

(13) Troubleshooting guide of power supply board (23" and 27")
a. No power supply

No power supply



Check if X501 FU501 is
Does AC voltage at C505 N
properly inserted?

Y


Does DC voltage at C528
(150~370V) N Check D502, R531, D508

Y


Check if the 15V DC of Check N501 or peripheral
N
N501 (pin13) circuit


Y


Check supplementary
power supply


36
b. No DC voltage output


No DC voltage output


Check if DC voltage of C536 is
N Check N502 or peripheral
3.3V(5V)
circuit
Y

Check if DC voltage of V505 B N Check main board
is 24V

Y

Check if DC voltage of C537 is
N
24V Check D515 or T501

Y

Check FU502




37
APPENDIX-A: Main assembly


Model Part name No.
LC-37FB32 Digital processing board 667.37FB32-69
Power board 667.L37T24-20
Analog board 667.37FB18-53
Video processing board 667.32FB18-40
Key board 667.32FB32-05
IR receiver board 667.32FB32-09
Remote control 301.D42FB6-06
Panel 335.37019-00
603-L37FB32-11
Ver.1.0