LG XA66 User manual

MICRO Hi-Fi SYSTEM
SERVICE MANUAL
MODEL: XA66 (XA66, XAS66F)
CAUTION
BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS”
IN THIS MANUAL.
MODEL: XA66 (XA66, XAS66F)SERVICE MANUAL
P/NO : AFN75496346 JUNE, 2011
Website http://biz.lgservice.com
Internal Use Only

CONTENTS
SECTION 1 ........ SUMMARY
SECTION 2 ........ CABINET & MAIN CHASSIS
SECTION 3 ........ ELECTRICAL
SECTION 4 ........ REPLACEMENT PARTS LIST
1-1

SECTION 1
SUMMARY
CONTENTS
SERVICING PRECAUTIONS................................................................................................................... 1-3
ESD PRECAUTIONS .................................................................................................................................. 1-5
SERVICE INFORMATION FOR EEPROM........................................................................................... 1-6
PROGRAM UPDATE GUIDE................................................................................................................... 1-7
SPECIFICATIONS ....................................................................................................................................... 1-8
1-2

1-3
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 lens.
6) Never attempt to disassemble the pick-up.
Spring has 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 allow
contact with fingers or other exposed skin.
Magnet
How to hold the pick-up
Conductive Sheet
Cotton swab
Pressure
Pressure
SERVICING PRECAUTIONS

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 or 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 (1 MΩ)
6) Care should be taken not to permit the laser pick-up to come in contact with clothing, in order to prevent stat-
ic 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 MΩ)Conductive
Sheet
Resistor
(1 MΩ)
Armband
1-4

1-5
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.
ESD PRECAUTIONS

SERVICE INFORMATION FOR EEPROM
POWER ON
Completed
FLD 'OPT-XXX'
Press front ‘STOP’ key
+ Remote control ‘FWD SKIP’ key.
Press ‘POWER’ key once.
FLD display 'E2P CLR'
Press front "Play" key
to move to appropriate position
and make changes
with front ‘FWD SKIP’ key.
FLD no disc status
Front ‘STOP’ + Remote control ‘FWD
SKIP’ push same timing during 5s. DETECT NEW EEPROM
(OPTION EDIT SCREEN)
NAME HEX
OPT 0000 (FM)
OPT 0100 (FM_RDS)
OPT 1010 (FM_AM)
. .
. .
. .
1-6

PROGRAM UPDATE GUIDE
1-7
1. HOW TO UPDATE ESS PROGRAM
(1) Rename the file name to download as “LG_(MODEL NAME)_(Vresion).ROM” in upper cases.
ex) XA66 : “LG_XA66_0905180.ROM”
Refer to the Standard for naming of software.
(2) Copy the file to the formatted USB, and burn it.
(3) Move to the USB function, and insert the USB to the set.
The upgrade information will be shown on the screen.
(4) Remove the USB.
(5) Remove and reconnect the power cable when it changes to logo screen from upgrade information.
Then the upgrade process is completed.
2. HOW TO UPDATE SANYO PROGRAM
(1) Change the file name to download as “(MODEL NAME)_(Version).HEX”. in upper cases
ex) XA66: XA66_0809262.HEX
(2) Copy the file to the root folder of USB storage.
(3) Put the USB into the set.
Then the upgrade process will be started with the upgrade information.
(4) If the upgrade process is complete, the set will be rebooted with “Complete” message.
3. HOW TO UPDATE MCS PROGRAM
(1) Change the file name to download as “(MODEL NAME)_(OPTION)_(Version).mcs”.
ex) XA66_0000_02.mcs
(2) Copy the file to the root folder of USB storage.
(3) Put the USB into the set. Change set function to USB function.
Then the upgrade process will be started with the upgrade information. FLD display "UPGRADE".
(4) If the upgrade process is complete, the set will be rebooted with “SUCCESS” message,
and set auto power off.
(5) Pull out the USB Storage. Press the power key.

SPECIFICATIONS
• GENERAL
Power supply 200 - 240 V ~ 50 / 60 Hz
Power consumption 50 W
Net Weight 2.8 kg
External dimensions (W x H x D) 170 x 253 x 242 (mm)
Operating temperature 5 °C ~ 35 °C
Operating humidity 5 % ~ 85 %
• TUNER
FM Tuning Range 87.5 ~ 108.0 MHz
AM Tuning Range 522 ~ 1,620 kHz
• AMPLIFIER
Output Power 30 W + 30 W
T.H.D 0.5 %
Frequency Response 50 Hz ~ 20 kHz
Signal-to-noise ratio 70 dB
• CD
Frequency response 100 Hz ~ 18 kHz
Signal-to-noise ratio 70 dB
Dynamic range 55 dB
• SPEAKERS
Type 2 Way 2 Speaker
impedance 6 Ω
Rated Input Power 30 W
Max. Input Power 60 W
Net Dimensions (W x H x D) 150 x 182 x 242 (mm)
Net Weight 1.9 kg
Note : Design and specifications are subject to change prior notice.
1-8

SECTION 2
CABINET & MAIN CHASSIS
CONTENTS
EXPLODED VIEWS..................................................................................................................................... 2-3
1. CABINET AND MAIN FRAME SECTION (XA66)..................................................................................... 2-3
2. PACKING ACCESSORY SECTION ......................................................................................................... 2-7
3. SPEAKER SECTION (XAS66F) ............................................................................................................... 2-8
2-1

2-2
MEMO

2-3 2-4
EXPLODED VIEWS
1. CABINET AND MAIN FRAME SECTION (XA66)
265
266
B
D
A
C
I
G
F
H
G
H
F
C
K
D
IE
K
J
E
B
A
M
J
L
261
260
453
453
453
451
451
452
453
452
453
451
453
452
A26
258
A43
A41
259L
259R
A42
266
A47
A46
454
454
262
263
CABLE2
CABLE3
A45
264
268
267
266
250
252
251
252
253
256
455
MAIN
MCU
SMPS
PHONE
DISPLAY
KEY
269
453
CABLE1
452
452
254
270
M
CON604
CN302
CON8
CN301
PN703
PN602
L300

2-5 2-6
MEMOMEMO

2-7
2. PACKING ACCESSORY SECTION
Battery808
Remote controller
900
Instruction Ass'y
801
803T Packing
803B Packing
Box
802
Bag
804
AAA

2-8
A60
3. SPEAKER SECTION (XAS66F)

SECTION 3
ELECTRICAL
CONTENTS
ELECTRICAL TROUBLESHOOTING GUIDE.................................................................................... 3-2
1. SMPS PART ........................................................................................................................................... 3-2
2. MUTE...................................................................................................................................................... 3-3
3. AUDIO ABNORMAL ............................................................................................................................... 3-4
4. AUDIO FUNCTION MODE..................................................................................................................... 3-5
5. IC301 TROUBLESHOOTING ................................................................................................................. 3-6
6. IC600 TROUBLESHOOTING ................................................................................................................. 3-7
7. IC601 TROUBLESHOOTING ................................................................................................................. 3-8
8. IC603 TROUBLESHOOTING ................................................................................................................. 3-8
9. U503 TROUBLESHOOTING .................................................................................................................. 3-9
10. TU101 FM TUNER MODULE................................................................................................................. 3-9
11. CD PART .............................................................................................................................................. 3-10
12. CD READING CHECK.......................................................................................................................... 3-11
13. USB PART............................................................................................................................................ 3-12
WAVEFORMS............................................................................................................................................. 3-13
1. CD SEARCHING WAVEFORM............................................................................................................ 3-13
2. SPINDLE DRIVE & MOTOR WAVEFORM .......................................................................................... 3-13
3. CD PLAYING WAVEFORM.................................................................................................................. 3-14
4. CD STOP ACTION WAVEFORM......................................................................................................... 3-15
5. CD READING WAVEFORM................................................................................................................. 3-15
6. CD PLAYING RF WAVEFORM............................................................................................................ 3-16
7. USB OPERATING WAVEFORM.......................................................................................................... 3-17
8. RADIO OPERATING WAVEFORM...................................................................................................... 3-17
WIRING DIAGRAM ................................................................................................................................... 3-19
BLOCK DIAGRAMS................................................................................................................................. 3-21
1. MAIN BLOCK DIAGRAM...................................................................................................................... 3-21
2. CD BLOCK DIAGRAM.......................................................................................................................... 3-23
CIRCUIT DIAGRAMS...............................................................................................................................3-25
1. SMPS CIRCUIT DIAGRAM .................................................................................................................. 3-25
2. DECODE CIRCUIT DIAGRAM............................................................................................................. 3-27
3. CD SERVO CIRCUIT DIAGRAM ......................................................................................................... 3-29
4. DISPLAY CIRCUIT DIAGRAM ............................................................................................................. 3-31
5. TUNER CIRCUIT DIAGRAM................................................................................................................ 3-33
6. AMPLIFIER CIRCUIT DIAGRAM ......................................................................................................... 3-35
CIRCUIT VOLTAGE CHART................................................................................................................. 3-37
PRINTED CIRCUIT BOARD DIAGRAMS ......................................................................................... 3-41
1. MAIN P.C.BOARD ................................................................................................................................ 3-41
2. SMPS P.C.BOARD............................................................................................................................... 3-43
3. MCU P.C.BOARD................................................................................................................................. 3-44
4. KEY P.C.BOARD.................................................................................................................................. 3-45
5. FRONT P.C.BOARD............................................................................................................................. 3-46
6. EARPHONE P.C.BOARD..................................................................................................................... 3-46
3-1

1. SMPS PART
5.0V
Replace F901 (Use same type fuse)
Replace D914
Replace RT901
Replace R904
Check or replace D906, R907
YES
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
F901 nomal?
D914 nomal?
RT901 nomal?
Is
VSTR(130V-310V) supplied to
IC901 pin5?
Replace BD901
Replace IC903, PC903
D906, R907 nomal?
NO
NO
NO
NO
BD901 nomal?
IC903, PC903 nomal?
Is
Vcc(9V-25V) supplied to
IC901 pin2?
Power line of main PCB is short
3-2
ELECTRICAL TROUBLESHOOTING GUIDE

2. MUTE
YES
YES
NO
YES
Mute
Replace Q704, Q705
Check U600 pin17
Check R622
Check IC603 pin69
Replace R622
NO
NO
NO
NO
Check "Low"
of Q704, Q705 "C"
Does "High" appear
at Q704, Q705 "B"?
Mute
3-3
ELECTRICAL TROUBLESHOOTING GUIDE

3. AUDIO ABNORMAL
Audio abnormal
Check the speakers connection
Check the function input
YES
YES
YES
YES
YES
NO
NO
Check the output
U702 pin2, 4, 8,10
Check the DC 9.5V
of U503 pin24
Check the "High" of U702 pin5
Check ZD703, D705
NO
NO
Check the input signal
of U702 pin7, 11
Check the DC 12V
of R701
Check the power circuit
3-4
ELECTRICAL TROUBLESHOOTING GUIDE

4. AUDIO FUNCTION MODE
Portable
Tuner
CD / USB
Check the input signal of CON541
Check the output signal of TU101 pin1, 2
Check the output signal of U502 pin55, 57
and refer to CD trobleshooting
Check the output signal of U503 pin19, 23
Check the output signal of U503 pin19, 23
Check the output signal of U503 pin19, 23
YES
YES
YES
NO
NO
NO
Check the input signal
of U503 pin7, 8
Check the input signal
of U503 pin1, 2
Check the input signal
of U503 pin3, 4
3-5
ELECTRICAL TROUBLESHOOTING GUIDE