LG MDD105 User manual

DVD Mini Hi-Fi System
SERVICE MANUAL
MODEL: MDD105 (MDS105V)
CAUTION
BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS”
IN THIS MANUAL.
MODEL: MDD105 (MDS105V)SERVICE MANUAL
P/NO : AFN73972690 JUNE, 2010
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
SOFTWARE UPGRADE PROCESS ..................................................................................................... 1-7
SPECIFICATIONS ....................................................................................................................................... 1-8
1-2

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
1-3
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

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
ESD PRECAUTIONS

POWER ON
FLD no disc status
Remote control ‘2’ + Front ‘STOP’
push same timing during 5s
FLD ‘OP-0….
Move to appropriate position
and make changes
with Rmc ‘skip, mode, play’ key.
Press STOP key
FLD ‘write ok’
Remote control ‘Fwd skip’ +
Front ‘STOP’ push same timing
FLD ‘E2P CLR’
Completed
NAME
OPT 0
OPT 1
OPT 2
OPT 3
OPT 4
OPT 5
OPT 6
OPT 7
OPT 8
OPT 9
DETECT NEW EEPROM
(OPTION EDIT SCREEN)
HEX
00
00
00
00
00
00
00
00
00
00
1-6
SERVICE INFORMATION FOR EEPROM

Important Notice :
When ugrade the software running. Do not shunt down the power, it tmay damage the unit.
1. MICOM UPGRADE
1) Copy the software file into USB flash, as the file name is LG_MDD105_XXXXXXX.HE
2) Insert the USB flash into USB host.
3) Set Function to USB position.
Appear onto VFD
UPGRADE
4) After finish, Set will automatically power off.
2. FLASH MEMORY UPGRADE
1) Copy the software file into USB flash, As the file name is LG_MDD105_XXXXXXX.RO
2) Insert the USB flash into USB host.
3) Set Function to USB position.
Appear onto VFD
CODE 00
NO USB
4) Manual Power off and Power on is finish.
1-7
SOFTWARE UPGRADE PROCESS

SPECIFICATIONS
• GENERAL
Power supply Refer to main label.
Power consumption Refer to main label.
Net Weight 5.3 kg
External dimensions (W x H x D) ( 272 x 336 x 352 ) mm
Operating conditions Temperature 5 °C to 35 °C, Operation status: Horizontal
Operating humidity 5 % to 85 %
Laser Semiconductor laser, wavelength, 760 to 800 nm
• TUNER FM/AM [MW]
FM Tuning Range 87.5 to 108.0 MHz or 87.50 to 108.00 MHz
FM Intermediate Frequency 128 kHz
AM Tuning Range 522 to 1 620 kHz, 520 to 1 710 kHz or 522 to 1 710 kHz
AM Intermediate Frequency 45 kHz
• AMPLIFIER
Output Power Front : 50 W x 2
• USB
Bus Power Supply (USB) DC 5 V 500 mA
USB Version USB 2.0 or USB 1.1
• CD
Frequency Response 40 to 20 000 Hz
Signal-to-noise ratio More than 60 dB
Dynamic range More than 50 dB
• TAPE
F.F/REW Time 120 sec (C-60)
Frequency Response 250 to 8 000 Hz
Signal to Noise Ratio 40 dB
Channel Separation 45 dB (P/B) / 40 dB (R/P)
Erase Ratio 50 dB (MTT-5511)
• SPEAKERS
Speaker name MDS105V
Type 2 Way 2 Speaker
Impedance 4 Ω
Rated Input Power 50 W
Max. Input Power 100 W
Net Dimensions (W x H x D) ( 202 x 337 x 237 ) mm
Net Weight 2.57 kg
1-8

SECTION 2
CABINET & MAIN CHASSIS
CONTENTS
EXPLODED VIEWS..................................................................................................................................... 2-3
1. CABINET AND MAIN FRAME SECTION (MDD105) ............................................................................... 2-3
2. TAPE DECK MECHANISM SECTION...................................................................................................... 2-5
3. SPEAKER SECTION ................................................................................................................................ 2-7
4. PACKING ACCESSORY SECTION ......................................................................................................... 2-8
2-1

2-2
MEMO

4-23-2
EXPLODED VIEWS
1. CABINET AND MAIN FRAME SECTION (MDD105)
O
MAIN
J
B
C
K
J
D
H
B
A
C
D
I
G
E
FH
F
M
L
L
M
282
460
283
E
A
K
I
SMPS
O
G
N
N
Q
252
A0 0
269
270
268 A46
271
A4 7
300
273
272
A4 3
A4 9
459
256
255
251
258
257
254
253
261
265
262
259
A4 5
263L
264L
264R
266L
266R
267L
267R
A41L
A41A
A4 1R
263R
CA BLE1
CA BLE2
250
KE Y2
MIC
KE Y3
KE Y1
VF D
LE D
US B
A4 8
CA BLE3
A0 1
A2 6
281
452
452
453
453
454
453
456
456
454
454
452
451
451
456
458
458
458
458
458
458
Q

2-5 2-6
2. TAPE DECK MECHANISM SECTION
A00
003
009
011 009
A02
015
007
001
037
A01
018
017
006 020
019
022
023
025

2-7
•LEFT / RIGHT SPEAKER (MDS105V)
3. SPEAKER SECTION
A60

2-8
Battery808
Remote controller900
Instruction Ass'y801
Packing803T
Packing
803B
Box802
Bag804
825 FM antenna
824 AM antenna
4. PACKING ACCESSORY SECTION

SECTION 3
ELECTRICAL
CONTENTS
ONE POINT REPAIR INSTRUCTION................................................................................................... 3-2
1. NO POWER PROBLEM ......................................................................................................................... 3-2
2. VFD DOESN'T DISPLAY........................................................................................................................ 3-4
3. THE DISC TRAY DOESN'T WORK ....................................................................................................... 3-5
4. NO BOOTING WHEN YOU TURN THE UNIT ON ................................................................................ 3-9
5. SPEAKER NO OUTPUT WHEN YOU TURN THE UNIT ON .............................................................. 3-13
6. VFD HAVEN'T SHOW WHEN YOU TURN THE UNIT ON.................................................................. 3-15
MAJOR WAVEFORMS............................................................................................................................ 3-16
1. IC1 MICOM INTERFACE WAVEFORM ............................................................................................... 3-16
2. IC100 MICOM INTERFACE WAVEFORM ........................................................................................... 3-17
3. SLED DRIVE AND MOTOR WAVEFORM........................................................................................... 3-18
4. SPINDLE DRIVE AND MOTOR WAVEFORM..................................................................................... 3-19
5. RF, FOCUS AND TRACKING ERROR WAVEFORM.......................................................................... 3-20
WIRING DIAGRAM ................................................................................................................................... 3-21
BLOCK DIAGRAM.................................................................................................................................... 3-23
CIRCUIT DIAGRAMS...............................................................................................................................3-25
1. SMPS - POWER CIRCUIT DIAGRAM ................................................................................................. 3-25
2. MAIN - DVD MPEG CIRCUIT DIAGRAM............................................................................................. 3-27
3. MAIN - MCU CIRCUIT DIAGRAM........................................................................................................ 3-29
4. MAIN - SERVO CIRCUIT DIAGRAM ................................................................................................... 3-31
5. MAIN - D/AC CIRCUIT DIAGRAM ....................................................................................................... 3-33
6. MAIN - AMP CIRCUIT DIAGRAM ........................................................................................................ 3-35
7. AUDIO DECK SYSTEM CIRCUIT DIAGRAM...................................................................................... 3-37
8. MIC / USB / KEY / VFD CIRCUIT DIAGRAM ...................................................................................... 3-39
CIRCUIT VOLTAGE CHART................................................................................................................. 3-41
PRINTED CIRCUIT BOARD DIAGRAMS ......................................................................................... 3-45
1. MAIN P.C.BOARD ................................................................................................................................ 3-45
2. SMPS P.C.BOARD............................................................................................................................... 3-49
3. FRONT P.C.BOARD............................................................................................................................. 3-51
3-1

1. NO POWER PROBLEM
No power problem occurs when you power on the unit.
1-1. F1, D3 and D6
1-1-1. Solution
Replace F1, D3, D6 on SMPS board.
1-1-2. How to troubleshoot (Countermeasure)
1) Look at the physical of fuse F1.
2) Check the bridge diode of D3, D6.
1-1-3. Service hint (Any picture / Remark)
Check with ohm meter is short!
Check with ohm meter is open!
- +
D6
DB105G
11
2
233
4
4
3
D16 FR104
D5
UF
56k/
C23 104/275V C24
472
C18
472
W16
Jumper
12
C21
471/400V
R16 1.5M/0.5W
L
T
U3
FSFM260N
GND
1
Vcc
2
Vfb 3
Ipk
4
Vstr
5
DRAIN 6
DRAIN 7
DRAIN 8
D11
FR104
R17
47k
C22
471/400V
RV1 471
C19
22uF/50V
C14
47uF/50V
t
RT1
2.7ohm/5W
W6 Jumper
12
C9
68uF/450V
C3
103/630V
C17 104/275V
C1
68uF/450V
R25 10
W7 Jumper
1 2
R13
47k
W17
Jumper
12
LF1
SQE2424
1
2
34
5
6
78
F1
T3.15AL250V
HS1 15*10
1
Q5
KTA1268
-+
D3
DB105G
11
22
3
3
4
4
LF2
SQE2424 1
2
34
5
6
78
3-2
ONE POINT REPAIR INSTRUCTION

No power problem occurs when you power on the unit.
1-2. C29 and C30
1-2-1. Solution
Replace C29, C30 on SMPS board.
1-2-2. How to troubleshoot (Countermeasure)
1) Check all of voltage.
Warn
Parts
resp
e
CAUTION:
Danger if fuse is incorrectly replaced.
Replace only with the type identical to fuse rating
and(or) model name described in main label.
C27 2.2uF/50V
PC3
LTV-817
11
2
2
3
344
C28
103/630V
R10 560
W15 Jumper
1
2
R14 18k
R19
2.2k
U5
KA431/TO
C32
224
R23
33k
W18 Jumper
12
D18 UG4D
T2
EER2828(AMP)
1
2
3
4
5
6
7
8
R18
56k/2W U6
KA431/TO
R28 470
R26
220
R27
150
R11 56
W13 Jumper
1
2
C29
1000uF/25V
W19 Jumper
12
R21
33k
R24
33k
R20
2k
R29
4.7k
R12
2.7k
W9
Jumper
1 2
R15
2.7k
PC1
LTV-817
C26 2.2uF/50V
C30
1000uF/25V
D19
UF4007
R22
33k
C35 222/400V
C25 470pF/1kV
W4 Jumper
12
W5 Jumper
1
2
1-2-3. Service hint (Any picture / Remark)
&&
3-3
ONE POINT REPAIR INSTRUCTION

2. VFD DOESN'T DISPLAY
Timer doesn't work(abnormal display).
2-1. D13
2-1-1. Solution
Replace D13 on SMPS board.
2-1-2. How to troubleshoot (Countermeasure)
1) Check J1 pin3 Ö-26 V at power.
2-1-3. Service hint (Any picture / Remark)
1.GND
2.GND
3.GND
4.-12V
5.+12V
6.+12V
7.5V
8.5.9V
9.3.5V
10.3.5V
11.GND
12.GND
13.36V
14.36V
15.36V
8.GND
7.CD_CTRL
6.PWR_CTRL
5.PWR_SENS
4.5.6V
3.VKK
2.FL-
1.FL+
Q3
KTA1268
W3 Jumper
1 2
Q2
KTA1273
C20
330uF/16V
R10 560
Q1
KTC3205
R8 1k C15
47uF/50V
C11
100uF/6.3V
R2 10k
C8
100uF/16V
R6
10k
W2
Jumper
1 2
R5
18k
W10 Jumper
1
2
C7
1000uF/25V
C13
100uF/25V
U4 278R33
IN
1OUT 2
GND
3CON 4
U1 78R05
IN
1OUT 2
GND
3CON 4
W11 Jumper
1 2
C5
1000uF/16V
D9
1N4148
W14
Jumper
1 2
R4 1k
C6
100uF/6.3V
D10
1N4148
C16
47uF/50V
W12 Jumper
1 2
J2
15P
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
W1 Jumper
1 2
Q4
KTC3205
C
2
u
F/50V
W8
Jumper
1 2
W9
Jumper
1
2
D13
3V
J1
8P
1
2
3
4
5
6
7
8
U2 78R12
IN
1OUT 2
GND
3CON 4
W4 Jumper
12
L1 22uH
R7
1k
3-4
ONE POINT REPAIR INSTRUCTION

3. THE DISC TRAY DOESN'T WORK
When you turn on the set, the disc tray won't work.
3-1. U1
3-1-1. Solution
Replace U1_KA78R05 on SMPS board.
3-1-2. How to troubleshoot (Countermeasure)
1) Check all of voltage.
2) 5 V unnormal.
3-1-3. Service hint (Any picture / Remark)
1.GND
2.GND
3.GND
4.-12V
5.+12V
6.+12V
7.5V
8.5.9V
9.3.5V
10.3.5V
11.GND
12.GND
13.36V
14.36V
15.36V
8.GND
7.CD_CTRL
6.PWR_CTRL
5.PWR_SENS
4.5.6V
3.VKK
2.FL-
1.FL+
Q3
KTA1268
W3 Jumper
1 2
Q2
KTA1273
C20
330uF/16V
R10 560
Q1
KTC3205
R8 1k C15
47uF/50V
C11
100uF/6.3V
R2 10k
C8
100uF/16V
R6
10k
W2
Jumper
1 2
R5
18k
W10 Jumper
1
2
/
25V
C13
100uF/25V
U4 278R33
IN
1OUT 2
GND
3CON 4
U1 78R05
IN
1OUT 2
GND
3CON 4
W11 Jumper
1 2
C5
1000uF/16V
D9
1N4148
W14
Jumper
1 2
R4 1k
C6
100uF/6.3V
D10
1N4148
C16
47uF/50V
W12 Jumper
1 2
J2
15P
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
W1 Jumper
1 2
Q4
KTC3205
W8
Jumper
1 2
W9
D13
3V
J1
8P
1
2
3
4
5
6
7
8
U2 78R12
IN
1OUT 2
GND
3CON 4
W4 Jumper
12
L1 22uH
R7
1k
3-5
ONE POINT REPAIR INSTRUCTION