LG LHS-55-TBC, LHS-55-TBS, LHS-55-TBW, LHTK-551-TB Service manual

DVD/CD & KARAOKE RECEIVER
SERVICE MANUAL
MODELS : LH-TK551TB/LH-T551TB
LHS-55TBC, LHS-55TBS, LHS-55TBW
MODELS : LH-TK551TB/LH-T551TB LHS-55TBC, LHS-55TBS, LHS-55TBWSERVICE MANUAL
1-1
[CONTENTS]
SECTION 1.GENERAL
• SERVICING PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
• ESD PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
• SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5
SECTION 2. AUDIO PART
• AUDIO TROUBLESHOOTING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
• WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
• BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
• SCHEMATIC DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
• PRINTED CIRCUIT DIARGAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22
SECTION 3.DVD & AMP PART
• ELECTRICAL TROUBLESHOOTING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1
• DVD PART SCHEMATIC DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-22
SECTION 4. EXPLODED VIEWS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-1
SECTION 5. SPEAKER PART . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-1
SECTION 6. REPLACEMENT PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-1
1-2
SERVICING PRECAUTIONS
NOTES REGARDING HANDLING OF THE PICK-UP
1. Notes for transport and storage
1) The pick-up should always be left in its conductive bag until immediately prior to use.
2) The pick-up should never be subjected to external pressure or impact.
2. Repair notes
1) The pick-up incorporates a strong magnet, and so should never be brought close to magnetic materials.
2) The pick-up should always be handled correctly and carefully, taking care to avoid external pressure and impact. If it is subjected to strong pressure or impact, the result may be an operational malfunction and/or damage to the printed-circuit board.
3) Each and every pick-up is already individually adjusted to a high degree of precision, and for that reason the adjustment point and installation screws should absolutely never be touched.
4) Laser beams may damage the eyes! Absolutely never permit laser beams to enter the eyes! Also NEVER switch ON the power to the laser output part (lens, etc.) of the pick-up if it is damaged.
5) Cleaning the lens surface If there is dust on the lens surface, the dust should be cleaned away by using an air bush (such as used for camera lens). The lens is held by a delicate spring. When cleaning the lens surface, therefore, a cot­ton swab should be used, taking care not to distort this.
6) Never attempt to disassemble the pick-up. Spring by excess pressure. If the lens is extremely dirty, apply isopropyl alcohol to the cotton swab. (Do not use any other liquid cleaners, because they will damage the lens.) Take care not to use too much of this alcohol on the swab, and do not allow the alcohol to get inside the pick-up.
Storage in conductive bag
Drop impact
NEVER look directly at the laser beam, and don’t let contact fingers or other exposed skin.
Magnet
How to hold the pick-up
Conductive Sheet
Cotton swab
Pressure
Pressure
SECTION 1. GENERAL
1-3
NOTES REGARDING COMPACT DISC PLAYER REPAIRS
1. Preparations
1) Compact disc players incorporate a great many ICs as well as the pick-up (laser diode). These components are sensitive to, and easily affected by, static electricity. If such static electricity is high voltage, components can be damaged, and for that reason components should be handled with care.
2) The pick-up is composed of many optical components and other high-precision components. Care must be taken, therefore, to avoid repair or storage where the temperature of humidity is high, where strong magnet­ism is present, or where there is excessive dust.
2. Notes for repair
1) Before replacing a component part, first disconnect the power supply lead wire from the unit
2) All equipment, measuring instruments and tools must be grounded.
3) The workbench should be covered with a conductive sheet and grounded. When removing the laser pick-up from its conductive bag, do not place the pick-up on the bag. (This is because there is the possibility of damage by static electricity.)
4) To prevent AC leakage, the metal part of the soldering iron should be grounded.
5) Workers should be grounded by an armband (1M Ω)
6) Care should be taken not to permit the laser pick-up to come in contact with clothing, in order to prevent static electricity changes in the clothing to escape from the armband.
7) The laser beam from the pick-up should NEVER be directly facing the eyes or bare skin.
Resistor (1 Mohm)
Conductive Sheet
Resistor (1 Mohm)
Armband
1-4
ESD PRECAUTIONS
Electrostatically Sensitive Devices (ESD)
Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components commonly are called Electrostatically Sensitive Devices (ESD). Examples of typical ESD devices are integrated circuits and some field-effect transistors and semiconductor chip components. The following techniques should be used to help reduce the incidence of component damage caused by static electricity.
1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off
any electrostatic charge on your body by touching a known earth ground. Alternatively, obtain and wear a commercially available discharging wrist strap device, which should be removed for potential shock reasons prior to applying power to the unit under test.
2. After removing an electrical assembly equipped with ESD devices, place the assembly on a conductive surface
such as aluminum foil, to prevent electrostatic charge buildup or exposure of the assembly.
3. Use only a grounded-tip soldering iron to solder or unsolder ESD devices.
4. Use only an anti-static solder removal device. Some solder removal devices not classified as "anti-static" can
generate electrical charges sufficient to damage ESD devices.
5. Do not use freon-propelled chemicals. These can generate electrical charges sufficient to damage ESD
devices.
6. Do not remove a replacement ESD device from its protective package until immediately before you are
ready to install it. (Most replacement ESD devices are packaged with leads electrically shorted together by conductive foam, aluminum foil or comparable conductive materials).
7. Immediately before removing the protective material from the leads of a replacement ESD device, touch the
protective material to the chassis or circuit assembly into which the device will by installed.
CAUTION : BE SURE NO POWER IS APPLIED TO THE CHASSIS OR CIRCUIT, AND OBSERVE ALL OTHER
SAFETY PRECAUTIONS.
8. Minimize bodily motions when handing unpackaged replacement ESD devices. (Otherwise harmless motion
such as the brushing together of your clothes fabric or the lifting of your foot from a carpeted floor can gener­ate static electricity sufficient to damage an ESD device).
CAUTION. GRAPHIC SYMBOLS
THE LIGHTNING FLASH WITH APROWHEAD SYMBOL. WITHIN AN EQUILATERAL TRIANGLE, IS INTENDED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF UNINSULATED “DANGEROUS VOLTAGE” THAT MAY BE OF SUFFICIENT MAGNITUDE TO CONSTITUTE A RISK OF ELECTRIC SHOCK.
THE EXCLAMATION POINT WITHIN AN EQUILATERAL TRIANGLE IS INTENDED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF IMPORTANT SAFETY INFORMATION IN SERVICE LITERATURE.
1-5
GENERAL
Power supply Refer to main label Power consumption Refer to main label Mass 3.9 kg External dimensions (W x H x D) 430 x 54 x 350 mm Operating conditions Temperature: 5°C to 35°C, Operation status: Horizontal Operating humidity 5% to 85%
CD/DVD
Laser Semiconductor laser, wavelength 650 nm Signal system PAL 625/50, NTSC 525/60 Frequency response (audio) 200 Hz to 20 kHz Signal-to-noise ratio (audio) More than 75 dB (1 kHz, NOP, 20 kHz LPF/A-Filter) Dynamic range (audio) More than 70 dB Harmonic distortion (audio) 0.5 % (1 kHz, at 12W position) (20 kHz LPF/A-Filter)
VIDEO
Video input 1.0 V (p-p), 75 Ω, negative sync., RCA jack x 1/ SCART (TO TV) Video output 1.0 V (p-p), 75 Ω, negative sync., RCA jack x 1/ SCART (TO TV) S-video output (Y) 1.0 V (p-p), 75 Ω, negative sync., Mini DIN 4-pin x 1
(C) 0.3 V (p-p), 75 Ω
Component Video output (Y) 1.0 V (p-p), 75 Ω, negative sync., RCA jack x 1
(Pb)/(Pr) 0.7 V (p-p), 75 Ω, RCA jack x 1
TUNER
FM
Tuning Range 87.5 - 108.0 MHz or 65.0 - 74.0 MHz, 87.5 - 108.0 MHz Intermediate Frequency 10.7 MHz Signal-to Noise Ratio 60 dB (Mono) Frequency Response 140 - 10,000 Hz
AM [MW]
Tuning Range 522 - 1,620 kHz or 520 - 1,720 kHz Intermediate Frequency 450 kHz
AMPLIFIER(LH-TK551TB/LH-T552TB)
Stereo mode 70W + 70W (8Ω at 1 kHz, THD 10 %) Surround mode Front: 70W + 70W (THD 10 %)
Centre*: 70W Surround*: 70W + 70W (8Ω at 1 kHz, THD 10 %) Subwoofer*: 150W (4Ω at 30 Hz, THD 10 %)
SPEAKERS
Satellite Speaker Centre speaker Passive Subwoofer
(LHS-55TBS) (LHS-55TBC) (LHS-55TBW) Type 1 Way 2 Speaker 1 Way 2 Speaker 1 Way 1 Speaker Impedance 8 Ω 8 Ω 4 Ω Frequency Response 150 - 20,000 Hz 150 - 20,000 Hz 40 - 1,500 Hz Sound Pressure Level 86 dB/W (1m) 86 dB/W (1m) 82 dB/W (1m) Rated Input Power 70 W 70 W 150 W Max. Input Power 140 W 140 W 300 W Net Dimensions
(WxHxD) 280 x 1200 x 280 mm 500 x 83 x 90 mm 195 x 402 x 360 mm
Net Weight 2.38kg 0.71kg 6.2kg
(* Depending on the sound mode
settings and the source, there may be no sound output.)
SPECIFICATIONS
2-1
SECTION 2. AUDIO PART
AUDIO TROUBLESHOOTING GUIDE
1. POWER SUPPLY CIRCUIT
2-2
2. FRONT CIRCUIT (1/2)
PIN3 PIN4 PIN9
CN902 CN902
: -32.4 VKK : -27.5 FL­: -23.7 FL+
: +5.0
2-3
3. FRONT CIRCUIT (2/2)
2-4 2-5
WIRING DIAGRAM
WIRELESS
PN801
CN350
OPTICALINSCART
JACK
MAIN PCB
PDM01 PDM03
23PIN 11PIN 24PIN 23PIN
OPTION
SW
AV1,2
COMPONENT
MONITOR OUT
S-VIDEO OUT
PN103
TUNER
PN104
SPEAKER TERMINAL
30PIN
PN302
AMP PCB
PN105
PN902 PN303
14PIN 14PIN
5PIN
MIC
JACK
MIC
JACK
6PIN
CN001
MIC&USB PCB
USB JACK
MD
PN005
PN002
PN001
SMPS PCB
VFD
FRONT
FRONT
PCB
PCB
H/P JACK
2-6 2-7
BLOCK DIAGRAM
Optical
Tuner
AV1
AV2
(option)
Monitor Out
S-AV
Component
Scart
(option)
USB Port
MIC
Wireless
L R V
L R V
G B R
L R L R G B R 8 16 V
MIC1 MIC2
7V
Tuner-L/R
AV1-L/R AV2-L/R
SCART-L/R
SCART-ID SCART-FB
(A)(T_CE,T_DO,T_DI,T_CLK,T_RDS_DATA,T_RDS,CLK)
Audio s/w
Bu 4052
CTL-A/B AV1-CVBS AV2-CVBS Monitor out SCART-CVBS out
C Y
ALC
BA 3308
MIC1_DET(A) MIC2_DET(A)
(B)
Slide
S/W
VIDEO-SW
Mixing
+
P
(R) ,Pr(R)
b
(A)
Video S/W NJM 2279 out (CVBS-S/W)
DVD-CVBS
Y Y(G)
USB Controller
CS 5340
ADC
/RST-AD
ADC
CS 5340
Fs = 48kHz
Fx
/RST-AD
SW1, SW2,MUTE1
(A)
Video
S/W
NJM2279
(Y-S/W)
ALRCK,ABCK MCLK,AMDAT
(A)
SPDI F
AD-DATA AD-BCK AD-LRCK
CS 8406
(slave)
(A)
C
YY
DVD BLOCK
CVB S MUTE
TR Mute
(ES 6698)
Mic Volume : OSD CTL
SS
T
12.288MHz
DIT
8406_SDI,8406_SD O 8406_CLK,8406_CE
(A)
8406_RST,8406_IN T
SPDIF
OPTION
LRCK
BCK ADAT 0,1,2,3 (FL/R,RL/R,C/SW )
AUDIO MICOM
LC876B48
(PIN MAP )
FRONT
PS 9818
(PWM)
(A) HP_DET
STA510A
AMP IC
AM
(A)
FAN1_CTL FAN2_CTL
PDN TH_W
FAN1
FAN2
H/P
OPTION
2-8 2-9
SCHEMATIC DIAGRAMS
1. POWER SCHEMATIC DIAGRAM_1
A B C D E F G H I J K L M N O P Q R ST
2-10 2-11
2. POWER SCHEMATIC DIAGRAM_2
A B C D E F G H I J K L M N O P Q R ST
2-12 2-13
3. MICOM SCHEMATIC DIAGRAM
A B C D E F G H I J K L M N O P Q R ST
2-14 2-15
4. FRONT SCHEMATIC DIAGRAM
A B C D E F G H I J K L M N O P Q R ST
2-16 2-17
5. DSP& SCHEMATIC DIAGRAM
A B C D E F G H I J K L M N O P Q R ST
2-18 2-19
6. I/O SCHEMATIC DIAGRAM
A B C D E F G H I J K L M N O P Q R ST
2-20 2-21
7. MAIN MIC SCHEMATIC DIAGRAM
A B C D E F G H I J K L M N O P Q R ST
Loading...
+ 41 hidden pages