LG LXD-2230-D Service manual
- 1-1 -
[CONTENTS]
❍ SECTION 1. GENERAL
• SERVICING PRECAUTIONS
.....................................................................................................
1-2
• ESD PRECAUTIONS
.................................................................................................................
1-4
• SPECIFICATION
........................................................................................................................
1-5
❍ SECTION 2. ELECTRICAL SECTION
• ADJUSTMENTS
.........................................................................................................................
2-1
•
AUDIO PART ELECTRICAL TROUBLESHOOTING GUIDE
.................................................................. 2-2
• BLOCK DIAGRAM
....................................................................................................................
2-11
• SCHEMATIC DIAGRAMS
........................................................................................................
2-13
• IC/TR VOLTAGE SHEET .......................................................................................................... 2-19
• WIREING DIAGRAM ................................................................................................................ 2-21
• PRINTED CIRCUIT DIAGRAMS .............................................................................................. 2-23
❍ SECTION 3. ELECTRICAL TROUBLESHOOTING GUIDE
• TROUBLESHOOTING
...................................................................................................................................
3-1
• DETAILS AND WAVEFORMS ON SYSTEM TEST AND DEBUGGING ....................................3-8
• DVD PART SCHEMATIC DIAGRAMS ...................................................................................... 3-21
• PRINTED CIRCUIT DIAGRAM ................................................................................................. 3-29
❍ SECTION 4. EXPLODED VIEWS
• CABINET AND MAIN FRAME SECTION.................................................................................... 4-1
• TAPE DECK MECHANISM: AUTOREVERSE DECK ................................................................. 4-3
• CD MECHANISM ........................................................................................................................ 4-5
❍ SECTION 5. SPEAKER PART
• SPEAKER PART
........................................................................................................................
5-1
❍ SECTION 6. REPLACEMENT PARTS LIST
• REPLACEMENT PARTS LIST
....................................................................................................
6-1
❏ 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.
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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
Pressure
Pressure
Cotton swab
Conductive Sheet
SECTION 1. GENERAL
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 (1MΩ)
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.
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.
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Armband
Conductive
Sheet
Resistor
(1 Mohm)
Resistor
(1 Mohm)
VOLUME KNOB
UP
DOWN
VOLUME
RESET jump wire
❐ 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]
- 1-4 -
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.
- 1-6 -
MEMO
- 2-1 -
TAPE DECK ADJUSTMENT
1. AZIMUTH ADJUSTMENT
Figure 1. Azimuth Adjustment Connection Diagram
CH1 CH2
Speaker Out
Playback Mode
Head
Test Tape
MTT-114
L ch
R ch
GND
Dual-trace
synchroscope
Electronic
Voltmeter
L out
R out
Unit
❏ ADJUSTMENTS
This set has been aligned at the factory and normally will not require further adjustment. As a result, it is not
recommended that any attempt is made to modificate any circuit. If any parts are replaced or if anyone tampers
with the adjustment, realignment may be necessary.
IMPORTANT
1. Check Power-source voltage.
2. Set the function switch to band being aligned.
3. Turn volume control to minimum unless otherwise noted.
4. Connect low side of signal source and output indicator to chassis ground unless otherwise specified.
5. Keep the signal input as low as possible to avoid AGC and AC action.
Deck Mode Test Tape Test Point Adjustment Adjust for
Palyback MTT-114 Speaker Out
DECK Screw
Maximum
Azimuth Screw
SECTION 2. ELECTRICAL SECTION
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❏
AUDIO PART ELECTRICAL TROUBLESHOOTING GUIDE
VKK PART
Does DC - 33V appear at
PN301 pin .
OK
Check the -27V of ZD901(-)
Check the Q902 TURN ON
Check the -277VLower of
C918(-)
Replace the Q902
Replace the D908, D909
OK
Refer to power
Troubleshooting
YES
YES
YES
YES
YES
NO
NO
NO
P-SENS PART
Does +5V appear at ZD900?
Check the pattern of
IC301 pin .
Check the waveform
of D907 (+).
Check the R901 and Replace
ZD 900
Replace the D907
YES
YES
NO
NO
26
31
- 2-3 -
POWER CIRCUIT
Check the Fuse
Check the DC output
of C732(+), C731(-)
Check the DC
Output of IC712, IC751
OK
Replace the Fuse
Check the 1.5V AC output of D701
Replace the D701
Replace the Transformer
YES
YES
YES
YES
NO
NO NO
MUTING CIRCUIT (MUTE)
Dose “High” appear at
Q701, Q702, Q703, Q751,
Q752 “B”
check the “Low” of Q701,
Q702, Q703, Q751, Q752 “C”
MUTE
Check the IC203 Troubleshooting
(ONLY Q201/Q251)
Check the “High” of Q704, Q705,
Q706 “E” (ONLY Q701/Q751)
Replace the Q704, Q705, Q706
Replace the TR
Refer to IC 301
Troubleshooting
YES
YES
YES
NO
NO
NO
- 2-4 -
AUDIO ABNORMAL
Check the output of
IC701, IC702, IC703 Pin 2, 4
Check the connecting to
speaker
Check the FUNCTION input
terminal
Check the input of IC701,
IC702, IC703, pin7, 11
Check the 12V output of
IC602, IC601
Check the 12V output of
IC704
OK
YES
NO
FUNCTION MODE AUDIO ABNORMAL
TAPE
Check the signal input
of IC601 pin6, 23
Refer to “IC201 Troubleshooting”
AUX
Chekc the signal input of IC600,
pin
5, 24
Check the signal input of JK400
- 2-5 -
Check the signal input of IC601
pin
3, 26
Check the signal input of PN704
pin11, 13, 15, 17, 19
Check the signal input of IC601 pin4, 25
Refer to “TUNER PACK Troubleshooting”
CD
TUNER
IC301 TROUBLESHOOTING
Check the power supplied to IC301
pin
17, 46, 72, 90?
Refer to “Power Circuit Troubleshooting”
Check the P-SENS
Replace the X301
Check the RESET circuit
Check the P-SENS “High” of IC301 pin26
Check the oscillation of X301
When power supplying to IC301 pin12.
(Low ➞ High)
Replace the IC301
YES
YES
YES
YES
NO
NO
NO
NO
- 2-6 -
Refer to “IC301
Troubleshooting”
IC601 TROUBLESHOOTING
IC602 TROUBLESHOOTING
Refer to “Power Circuit Troubleshooting”
Check the Data of IC301 pin87, 88
(CD ➞ TAPE FUNCTION)
Refer to power Troubleshooting
Check the Data of IC301 pin 85, 86
Check the patter of IC301 & IC602
Replace the
IC601
Check the pattern of
IC301 & IC601
Check the power supplied
to IC601 pin1
Check the CLK Data of IC601 pin14, 15
Check the FUNCTION SELECTOR
END
Check the Power supplied to IC602 pin 1
Check the CLK Data of IC602 pin9, 10
Replace the IC602
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
- 2-7 -
TUNER PACK TROUBLESHOOTING
Check the 9V of PN602 pin2
Check the GND of PN602 pin 4, 10
Check the pattern
Check the DC of C670
Check the power
YES
NO
PLAY
Check the VCC supplying to IC201 pin4
Refer to “Power Circuit
Troubleshooting”
Check the Deck Mecha
Replace the Deck
Mecha.
Replace the IC201
Check the signal output of IC201 pin3, 6
Check the “LOW” of Q201, Q251, “B”
YES
YES
YES
NO
NO
NO
- 2-8 -
REC (Q252, Q202 ON / R273, R223 HIGH)
Check signal supplied to IC203 pin2, 8 ?
Check the output of IC203 pin3, 7
Check the “output” of L201 pin5
Refer to “power circuit Troubleshooting”
Check the power
supplying to C227(+)
Check the oscillation
of Q204, “E”
Check the signal of
R212, R262
Check the Pattern
Check the Vcc power of IC203 Pin6
Check the oscillation of L201 pin 1, 3
Replace the DECK
Check the “Low” of Q202,
Q252 “B”
Replace the Q202, Q252
Check the “Low” of
IC501 pin9
Refer to
“Power Circuit
Troubleshooting”
Check the 0.6V of
Q205 “B”
Replace the L201
YES
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
NO
- 2-9 -
• POWER P.C. BOARD (SOLDER SIDE)
- 2-10 -
MEMO
2-11 2-12
❏ BLOCK DIAGRAM
NOTE: Warning
Parts that are shaded are critical With respect
to risk of fire or electrical shock.
❏ SCHEMATIC DIAGRAMS
• MAIN SCHEMATIC DIAGRAM
2-13 2-14
2-15 2-16
• FRONT SCHEMATIC DIAGRAM
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