LG LX-D2560A User manual

:
SERVICE MANUAL
MINI HOME THEATER
SERVICE MANUAL
MODEL : LX-D2560A(LXS-D2560V)
LX-D2960A(LXS-D2960V)

- 1-1 -
[CONTENTS]
❍SECTION 1. GENERAL
• SERVICING PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
• ESD PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
• SPECIFICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5
❍SECTION 2. EXPLODED VIEWS
1. CABINET AND MAIN FRAME SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2. DECK MECHANISM EXPLODED VIEW (5 CHANGER) . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
3. TAPE DECK MECHANISM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
4. SPEAKER EXPLODED VIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-7
❍SECTION 3. ELECTRICAL SECTION
•ELECTRICAL TROUBLESHOOTING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1
•INTERNAL BLOCK DIAGRAM of ICs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-13
•WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-25
•BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-27
•SCHEMATIC DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-29
•PRINTED CIRCUIT DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-41
❍SECTION 4. DVD PART ELECTRICAL
•DVD ELECTRICAL TROUBLESHOOTIHG GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-1
•DVD SCHEMATIC DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-15
•DVD PRINTED CIRCUIT DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-23
❍SECTION 5. MECHANISM OF DVD PART
•DECK MECHANISM DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-1
•EXPLODED VIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-7

- 1-2 -
SECTION 1. GENERAL
❏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

- 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 magnet-
ism 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 sta-
tic 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.
CLEARING MALFUNCTION
You can reset your unit to initial status if malfunction occur(button malfunction, display, etc.).
Using a pointed good conductor(such as driver), simply short the RESET jump wire on the inside of
the volume knob for more than 3 seconds.
If you reset your unit, you must reenter all its settings(stations, clock, timer)
NOTE: 1. To operate the RESET jump wire, pull the volume rotary knob and release it.
2. If you wish to operate the RESET jump wire, it is necessary to unplug the power cord.
Resistor
(1 Mohm) Conductive
Sheet
Resistor
(1 Mohm)
Armband
RESET jump wire
VOLUME
VOLUME KNOB
DOWN
UP

- 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 sur-
face 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 gen-
erate 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 “DAN-
GEROUS 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 -
❏SPECIFICATIONS
General
Power supply Refer to the main label.
Power consumption 50 W (LX-D2560A model)
Net Weight 5.9 kg
External dimensions (W x H x D) 190 X 352 X 295 mm
Tuner/Amplifier
FM Tuning Range 87.5 - 108.0 MHz or 65 -74 MHz, 87.5 -108.0 MHz
Intermediate Frequency 10.7 MHz
Signal to Noise Ratio 60/55 dB (Mono/Stereo)
Frequency Response 50 - 10000 Hz
AM Tuning Range 522 - 1620 kHz or 520 - 1720 kHz
Intermediate Frequency 450 kHz
Signal to Noise Ratio 30 dB
Frequency Response 140 - 1800 Hz
Output Power Front: 100 W + 100 W (4 Ω, THD 10 %) - LX-D2960A model
Front: 50 W + 50 W (4 Ω, THD 10 %) - LX-D2560A model
T.H.D 0.5 %
Frequency Response 40 - 20000 Hz
Signal-to-noise ratio 75 dB
DVD/VCD/CD player
Frequency response (audio) 40 - 20000 Hz
Signal-to-noise ratio (audio) More than 75 dB (1 kHz)
Signal-to-noise ratio (video) More than 55 dB (1 kHz)
Dynamic range (audio) More than 80 dB
Video output 1.0 V (p-p), 75Ω
S-video output (Y) 1.0 V (p-p), 75Ω
(C) 0.3 V (p-p), 75Ω
Component Video output (Y) 1.0 V (p-p), 75 Ω
(Pb)/(Pr) 0.7 V (p-p), 75Ω
Speakers
Speaker Name Front Speaker (L/R)
Type Bass Reflex 2Way 3Speaker (LXS-D2960V Model)
Bass Reflex 2Way 2Speaker (LXS-D2560V Model)
Impedance 4 Ω
Frequency Response 60 - 20000 Hz
Sound Pressure Level 85 dB/W (1m)
Rated Input Power 100 W (LXS-D2960V)
Max. Input Power 200 W (LXS-D2960V)
Net Dimensions (W x H x D) 190 X 351 X 295 mm (LXS-D2960V)
Net Weight 4.8 kg (LXS-D2960V)
Cassette tape player
Tape Speed 3000 ±3 % (MTT-111.
NORMAL-SPEED)
Wow Flutter 0.25 %
(TT -111, JIS-WTD)
F.F/REW. Time 120 sec (C-60)
Frequency Response 250 - 8000 Hz
Signal to Noise Ratio 43 dB
Channel Separation 50 dB (P/B)/45 dB (R/P)
Erase Ratio 55 dB (MTT-5511)

- 1-6 -

SECTION 2. EXPLODED VIEWS
1. CABINET AND MAIN FRAME SECTION
A26
A51
263
A000
256
255
254
253
251
250
MAC
257
463
262
261 463
463
A48
259
274
A44
273
276
A46
265
264
A50
A47
300
450
SMPS
MAIN
DVD
FRONT
252
2-1 2-2
NOTE) THE EXCLAMATION POINT WITHIN AN
EQUILATERAL TRIANGLE IS INTENDED
TO ALERT THE SERVICE PERSONNEL TO
THE PRESENCE OF IMPORTANT SAFETY
INFORMATION IN SERVICE LITERATURE.

2-3 2-4
2. DECK MECHANISM EXPLODED VIEW (5 CHANGER)
A26
003
075
023
011
038
073
037
032
062
031
004
005
006
007
001
002
071
431
074
072

2-5 2-6
3. TAPE DECK MECHANISM
1011
1013
1009
1009
1003
1002
1007
1037
1006
1018
1017
1019 1020
1021
1022
A001
1023
A000
1025
A002
1015

- 2-7 -
4. SPEAKER EXPLODED VIEW
758
757
A700
756
754 755
753
752
751
750
759

- 2-8 -

- 3-1 -
SECTION 3. ELECTRICAL SECTION
❏ELECTRICAL TROUBLESHOOTING GUIDE
Check P7904 6PIN P-SENS Refer to SMPS
Troubleshooting
Check if IC101 KIA7042
input is over 5V.
Check if output voltage
of IC101 KIA7042 is 4.3V
Check the related part
of IC101 KIA7042
Replace the
related parts
OK
Check power of both
terminals of IC101 KIA7042
Check IC100 78KO/KF2
1 PIN power
OK
YES
NO
NO
NO NO
YES
YES
YES
YES
■MICOM PART CHECK I

- 3-2 -
Check Q102 BASE
PIN 0.6V HIGH
Check Q102 COLLECTOR
Check output power
of IC101 KIA7042 is
over 4.3V.
Check the related
part.
Replace the
related parts
OK
Replace the
related parts
Check the related part.
OK
Check IC103 8PIN IC100
19,20,59 PIN 5V
Check the working condition
X101: 32.768kHz
X100: 9.8304MHz
OK
Check P7904 5PIN 5.6V
Refer to SMPS
Troubleshooting
Check D101 1SR35
output is working on 5V
Check the related part
OK
Replace the
related parts
Check power of both
terminals of D101 1SR35
Check Q101 EMITTER 5V
and COLLECTOR 5V
NO
NO
NO
NO
NO
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
■MICOM PART CHECK II

- 3-3 -
Check IC100 78KOKF2
22,24 PIN
22 PIN DATA 22 PIN CLK Check MICOM power 5V Refer to MICOM
Troubleshooting
Replace the related parts
Check the related part
OK
Refer to SMPS
Troubleshooting
Check P7302 assembly
Check power of each PIN
OK
Replace the related part
OK
Check P7904 1,2,3 power.
F1+,F2- both terminals: over
3.7V Check power VKK: over
26V.
Check P7302 connection
condition and power F1+,F2-
both terminals: over 3.7V
Check power VKK: over 26V
Check 25 PIN:5.6V
Check IC301 PT6324
power 50 PIN VKK:-26V
9.52 PIN +5V
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
NO NO
NO
NO
NO
NO
■IC103 KS4CD21CS CHECK
■FLD DISPLAY CHECK

- 3-4 -
Check IC100 ➞ IC301 DATA
communication
PIN PIN
75 PIN ➞ 3PIN STB
76 PIN ➞ 2PIN DO
77 PIN ➞ 4PIN DI
78 PIN ➞ 1PIN CLK
When 5V fails,check
D3191SR35 input and
output power
Check the related part
Check 76 PIN ➞ DO
➞ DATA input
Check the related part
Replace the related part
OK
Replace the related part
OK
FLT light on
OK
IC100
75 PIN ➞ STB
77 PIN ➞ 4PIN DI
78 PIN ➞ 1PIN CLK
Check Data output.
YES
YES
YES YES
YES
YES
YES
YES
NO
NO
NO
NO

- 3-5 -
Check P7905 9PIN 3.3V
Check if X601 12.288MHz is
working.
Check IC604 PS9829
86 PIN CLK input
Check output of
IC100 78KOKF2
21 ➞ PWM_CLK
22 ➞ PWM_DATA
23 ➞ PWM_REST
Check IC604 PS9829 DATA
input
78 PIN ➞ DATA
79 PIN ➞ CLK
96 PIN ➞ REST
Check PWM MODULATOR
output
FL:75(+)74(-) FR:71(+)70(-)
SW:68(+)67(-) CEN:62(+)61(-)
SL:59(+)58(-) SR:52(+)51(-)
OK
Check IC604 PS9829 VDD
PIN power (3,10,22,29,39,47,
56,65,72,87,94) Check X601
2PIN 3 3V
Refer to SMPS
Troubleshooting
Check the related part of
X601
OK
Check R668(470Ω) output
OK
Check resistance output of
LINE
DATA: R671
CLK: R670
RST: R665
OK
Check DVD ASS`Y PS9829
communication condition (P7403)
Check IC604 PS9829 DATA input
OK
Check IC604 PS9829 part.
Replace the related
part
Replace the related
part
Replace the related
part
Refer to DVD
Troubleshooting
Check resistance
output of each LINE
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
■PWM MODULATION PART

- 3-6 -
P7905 3 PIN+12 13,14,15
PIN 32V
Check input power of
eachIC700,701,702,703
34,29,26,21 PIN.
Check input power of each
IC 700,701,702,703
1,36,17,18,19 PIN +12V
Check PWM MODULATOR
input of each IC 4,6,14,16
PIN
Check POWER IC 700,701,
702,703 34,29,27,20 PIN
output.
Check output LINE COIL
OK
Refer to SMPS
Troubleshooting
Check resistance power of
each LINE
IC700:R702,701,726,727,724
IC701:R730,729,750,753,752
IC702:R756,755,768,771,770
IC703:R774,773,794,797,796
Replace the related parts
YES
YES
YES
YES
YES
YES
NO
NO
NO
■POWER AMP PART CHECK

- 3-7 -
Check if JK800 contacts with
Check IC200 (BU4052)
4, 11PIN input waveform.
Check IC200 (BU4052)
3, 13PIN output waveform.
Check IC801 (MC4580)
2, 6PIN input waveform.
OK
Check IC200 (BU4052)
16PIN VDD, 8PIN VSS power.
Check u-COM (IC301)
83PIN, 84PIN
communication.
Refer to SMPS
Troubleshooting.
Replace the related parts
Check IC801 (MC4580)4PIN
VSS, 8PIN VDD power.
Replace the related parts.
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
■AUX FUNCTION