LG MAX220UB User manual

P/NO : AFN75741202 MARCH, 2012
DIGITAL MEDIA
RECEIVER
SERVICE MANUAL
MODEL: MAX220UB
CAUTION
BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS”
IN THIS MANUAL.
Website http://biz.lgservice.com
Internal Use Only
MODEL: MAX220UBSERVICE MANUAL

1-1
CONTENTS
SECTION 1 SUMMARY
SERVICING PRECAUTIONS .............................................................................................................................1-2
ESD PRECAUTIONS..........................................................................................................................................1-3
SPECIFICATIONS ..............................................................................................................................................1-4
LOCATION OF USERS CONTROLS.................................................................................................................1-5
HOW TO SETTING THE OPTION CODE ..........................................................................................................1-6
FIRMWARE UPGRADE METHOD.....................................................................................................................1-7
HOW TO CONNECT AUDIO SET TO POWER SUPPLY..................................................................................1-8
SECTION 2 ELECTRICAL
ELECTRICAL TROUBLESHOOTING GUIDE....................................................................................................2-1
1. SYSTEM CONTROL ERROR CORRECTION FLOW CHART .................................................................2-1
2. SOUND ERROR CORRECTION FLOW CHART......................................................................................2-4
3. DISPLAY ERROR CORRECTION FLOW CHART....................................................................................2-7
4. TUNER ERROR CORRECTION FLOW CHART.......................................................................................2-8
5. USB ERROR CORRECTION FLOW CHART............................................................................................2-9
6. AUX ERROR CORRECTION FLOW CHART..........................................................................................2-11
WAVEFORMS...................................................................................................................................................2-12
CIRCUIT VOLTAGE CHART............................................................................................................................2-13
INTERNAL BLOCK DIAGRAM OF ICs ...........................................................................................................2-14
1. IC601 (BD3702FV)...................................................................................................................................2-14
2. IC801 (LV5693P) .....................................................................................................................................2-15
3. IC804 (TB2931HQ) ..................................................................................................................................2-17
WIRING DIAGRAM...........................................................................................................................................2-19
BLOCK DIAGRAMS .........................................................................................................................................2-21
1. MAIN BLOCK DIAGRAM .........................................................................................................................2-21
2. FRONT BLOCK DIAGRAM......................................................................................................................2-23
3. ELECTRICAL BLOCK DIAGRAM............................................................................................................2-25
CIRCUIT DIAGRAMS .......................................................................................................................................2-27
1. MAIN_1 CIRCUIT DIAGRAM...................................................................................................................2-27
2. MAIN_2 CIRCUIT DIAGRAM...................................................................................................................2-29
3. FRONT CIRCUIT DIAGRAM ...................................................................................................................2-31
PRINTED CIRCUIT BOARD DIAGRAMS ........................................................................................................2-33
1. MAIN P.C.BOARD ...................................................................................................................................2-33
2. FRONT P.C.BOARD ................................................................................................................................2-35
SECTION 3 EXPLODED VIEWS
1. CABINET AND MAIN FRAME SECTION ..................................................................................................3-1
SECTION 4 REPLACEMENT PARTS LIST

1-2
SECTION 1 SUMMARY
SERVICING PRECAUTIONS
1. Always disconnect the power source before:
1) Removing or reinstalling any component, circuit board, module or any other instrument assembly.
2) Disconnecting or reconnecting any instrument electrical plug or other electrical connection.
3) Connecting a test substitute in parallel with an electrolytic capacitor in the instrument.
CAUTION: A wrong part substitution or incorrect polarity installation of electrolytic capacitors may result in an
explosion hazard.
2. Do not defeat any plug/socket B+ voltage interlocks with which instruments covered by this service
manual might be equipped.
3. Do not apply power to this instrument and or any of its electrical assemblies unless all solid-state de-
vice heat sinks are correctly installed.
4. Always connect a test instrument’s ground lead to the instrument chassis ground before connecting
the test instrument positive lead. Always remove the test instrument ground lead last.
1) The service precautions are indicated or printed on the cabinet, chassis or components. When servicing,
follow the printed or indicated service precautions and service materials.
2) The Components used in the unit have a specified conflammability and dielectric strength. When replacing
any components, use components which have the same ratings. Components marked in the circuit diagram
are important for safety or for the characteristics of the unit. Always replace with the exact components.
3) An insulation tube or tape is sometimes used and some components are raised above the printed writing
board for safety. The internal wiring is sometimes clamped to prevent contact with heating components.
Install them as they were.
4) After servicing always check that the removed screws, components and wiring have been installed correctly
and that the portion around the service part has not been damaged. Further check the insulation between
the blades of attachment plug and accessible conductive parts.

1-3
ESD PRECAUTIONS
Electrostatically Sensitive Devices (ESD)
Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components com-
monly 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 know earth ground. Alternatively, obtain and wear a com-
mercially 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 de-
vices.
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 ARROWHEAD 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 INTENED TO ALERT
THE SERVICE PERSONNEL TO THE PRESENCE OF IMPORTANT SAFETY INFORMATION IN
SERVICE LITERATURE.

1-4
SPECIFICATIONS
• General
Output Power 53 W x 4 CH (Max.)
Power Source DC 12 V
Speaker impedance 4 Ω
Ground System Negative
Dimensions (W x H x D) 178 x 50 x 168 mm (without Control Panel)
Net Weight 0.97 kg
• TUNER
FM Tunning Range 87.5 to 108.0 MHz
S/N Ratio 55 dB
Distortion 0.7 %
Usable Sensitivity 12 dBμV
AM (MW) Tunning Range (520 to 1720) kHz or (522 to 1620) kHz
S/N Ratio 50 dB
Distortion 1.0 %
Usable Sensitivity 28 dBμV
• AUX
Frequency Response 20 Hz to 20 kHz
S/N Ratio 80 dB
Distortion 0.1 %
Channel Separation (1 kHz) 45 dB
Max Input Level (1 kHz) 1.1 V
• USB
Version USB 1.1 or USB 2.0 Full Speed
Bus Power Supply (USB) DC 5 V 1.5 A
• Line OUT (Optional)
Frequency Response 20 Hz to 20 kHz
Output Voltage 2 V (Max.)
• Subwoofer (Optional)
Frequency Response 20 Hz to 120 Hz
Output Voltage 2 V (Max.)
Design and specifications are subject to change without notice.

1-5
LOCATION OF USERS CONTROLS
FRONT PANEL
AB C DEF G H
IJKL MNO
ASRC / • OFF
- When pressed, selects function sources.
- When pressed and held, powers unit on or off.
B
Plays and pauses playback.
MUTE
Temporarily stops the sound.
CPRESET/LIST/ENTER (Volume knob)
- Adjusts volume level.
- Confirms the settings.
- Checks files or preset stations.
DDISP
- Press it, you can check the clock time.
- Press and hold it, you can turn on/off the
display window and the light of LED buttons.
EBAND
- Selects a band in Tuner mode.
- Moves to a next USB drive.
• TA (Optional)
- Searches stations that have TA / TP
information, when it is pressed and held.
FRemote Sensor (Optional)
GDisplay window
HUSB port
I
Returns to the previous step.
J/
Skip / Search / Seek / Tune
K• MENU
Activates setting menu.
FUNC
In each mode, sets playback items.
L
- Moves to the previous or next preset station in
TUNER
- Moves 10 MP3 / WMA files backward or
forward if there is no folder or one folder on an
USB.
- Moves to the previous or next folder if there
are more than 2 folders on an USB.
MEQ / • 3D
Improves sound quality.
- When pressed, selects the EQ function.
- When pressed and held, selects the 3D
SOUND function.
N
Opens the front panel.
OAUX
If connected to other portable player, you can
enjoy music from it on the unit.

1-6
HOW TO SETTING THE OPTION CODE
1. Option Table
Option Codes for Media Receiver products of 2012 will be defined as below
* OPTION TABLE
INDEX AREA RDS OPTION CODE SUFFIX
1 EU SUPPORT 111
EDEULL*
EDZALL*
EESPLL*
EHUNLL*
EMARLL*
ESWELL*
ETUREL*
EZAFLL*
2 EU SUPPORT 112 ERUSLL*
3 EU PS_RT_ONLY 121
EINDLL*
EIRNJL*
EISRRL*
ENGALL*
ESAUBL*
YEGYIL*
4 S.America PS_RT_ONLY 221
ECHLLL*
ECOLLL*
EPANLL*
PBRALL*
YMEXCL*
The option code is comprised of 3 digits and each digit has a range 1~6.
In the 2012, Media Receiver Product has totally four option codes from entire suffixes.
2. Operation
1. Entering Option Setting Function
1) Power off on the radio source.
2) Push and hold the SRC(PWR) Key for 5 seconds, then It goes to the version display mode.
3) Push BAND Key until the LCD displays “OPTION(OPTN) XYZ”.
(The XYZ means the Option Code)
2. How to change the option code
1) The Input mode can be set by press the volume knob, the first digit will be blinking until the
new code is set.
2) The number what you want to input could be selected by spinning the volume knob clockwise or
counterclockwise.
And then, if you push the volume knob, the selected number will be changed and the focus is moving
to the next.
You can also input the new option code of 1~6 by using preset keys if they are on the front panel.
3) If the new option code is acceptable, “SUCCESS XYZ” will be displayed on the LCD, and then it’ll reset
soon automatically.
4) If the new option code is not acceptable, “CODE ERR” will be displayed on the LCD.
To retry to change the option code, push the volume knob again.

1-7
FIRMWARE UPGRADE METHOD
[ MAIN AND CD FIRMWARE UPGRADE ]
1. Confirmation of version information
• Change the Source of audio set to tuner. (Default: tuner)
• Turn power off using power key.
• Press power key for 5 s. (After power on, continue pressing)
• After 5 s, beep sound rings two times.
Then version information would show up at display.
• In order to check version of MAIN and CD system, Press band key.
2. Upgrade Program reading
• Insert update USB in ACC on state and then is displayed in order.
USB : [USB Check →MN(CD) DNLD?]
3. Upgrade start
• In order to start upgrade, Press Play/Pause Key until “CHECKING” Display on the LCD.
4. Upgrade progress display
• Upgrade is in progress now.
CD Download : [CHECKING →ERASE →WRITE →I-VRF →D-VRF]
MN Download : [CHECKING →WRITE →DOWN OK]
5. Upgrade Completion
• When Upgrade finished, the display shows up “DOWN OK”. After a while, the audio set is
reset automatically.
• Caution!
If power is off on the way of upgrading firmware, the set can’t be recovered.
Therefore pay lots of attention for power not to be off.

1-8
• It is sufficient only to supply power for upgrade.
• Shown from the right figure, connect yellow line (Battery) and red line (Ignition) to plus and minus terminal
respectively.
• Jack is connected to the audio set via its shapes matched each other.
• We need power supply for operation of audio set (Voltage : 10~16 V Current : Over 20 A)
Before connection between set and power supply, adjust voltage level to 16 V typically (It is okay up to 10 V.)
Power Supply has a variety of shapes and capacity of voltage and current.
At first check these things.
HOW TO CONNECT AUDIO SET TO POWER SUPPLY

2-1
SECTION 2 ELECTRICAL
ELECTRICAL TROUBLESHOOTING GUIDE
1. SYSTEM CONTROL ERROR CORRECTION FLOW CHART
No power?
Something wrong with the System control?
OK
YES
F301 Inside of JK801
NO
Checked the Fuse?
JK801(1, 2, 3, 4)
Checked the Back up
VDD and GND?
Checked the Regulator
Back up VDD?
Checked the Main
Micom VDD?
Checked the Main
Micom GND?
Checked the Main
Micom X-tal?
Checked the Main
Micom reset?
Checked the ACC in?
Checked the Front
Panel Key input?
IC801(15, 14)
IC401(14, 40, 55, 89)
Checked the Main Micom
B+ Detect?
IC401(11, 39, 56, 88)
X401, X402
IC401(8), IC402
Q802, R459, IC401(3)
IC401(15, 16), CN402(7, 8)
1A 1B 1C 1D 1E
IC401(4, 21)
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
NO
NO

2-2
Not available to Remocon?
OK
YES
RC902, R961
YES
NO
Checked the
Remocon Sense VDD?
YES
R962, IC401(7), CN402(11)
NO
Checked the
Remocon Sense line?
1A
Not available to Volume control?
OK
YES
EV901, IC401(6, 68), CN402(14, 15)
YES
NO
Checked the
Encoder volume?
YES
IC401(31, 32), IC601(25, 26)
NO
Checked the
Volume IC control?
1B
Not available to Key control?
OK
YES
SW901 ~ SW907, SW909 ~ SW912
YES
NO
Checked the
Tact switch?
YES
IC401(15, 16), CN402(7, 8)
NO
Checked the
Key line?
1C
[OPTIONAL]

2-3
Not available to ANT(Motor Type) control?
OK
YES
D808, IC801(6, 11), IC401(94)
NO
Checked the
ANT control?
YES
1D
Not available to Remote(External AMP) control?
OK
YES
JK801(9), IC401(84),
Q811, Q812, Q813
NO
Checked the
Remote control?
YES
1E [OPTIONAL]

2-4
2. SOUND ERROR CORRECTION FLOW CHART
No sounds of All Functions?
Something wrong with the Sound?
OK
YES
IC601(24)
YES
NO
Checked the
E-VR VDD?
IC601(27)
YES
NO
Checked the
E-VR GND?
IC601(25, 26), IC401(31, 32)
YES
NO
Checked the
E-VR control?
IC601(15), IC401(98)
YES
NO
Checked the E-VR
Mute control?
IC601(1, 2, 3, 4, 5, 6, 7, 9,
18, 19, 20, 21, 22, 23)
YES
YES
NO
Checked the E-VR
Signal in/out?
IC804(1, 2, 8, 13, 18, 24)
YES
NO
Checked the
Power IC GND?
IC804(6, 20)
NO
Checked the
Power IC VDD?
IC804(4, 22), IC401(85, 87)
YES
NO
Checked the
Power IC control?
IC804(3, 5, 7, 9, 11, 12, 14,
15, 17, 19, 21, 23)
YES
NO
Checked the Power
IC Signal in/out?
JK801(11, 12, 13, 14, 15, 16, 17, 18)
YES
NO
Checked the
Main connector?
2A 2B 2C

2-5
Hearing the Pop Noise?
OK
YES
IC401(87, 96, 98), IC601(15), IC804(22),
Q601, Q602, Q603, Q604, Q607
NO
Checked the
Mute contorl?
YES
2A
No Sound External AMP?
OK
YES
IC601(18, 19, 20, 21, 22, 23)
NO
Checked the
Line Out signal?
YES
Q601, Q602, Q603, Q604, Q607
NO
Checked the Line Out
AMP Mute control?
YES
JK601
NO
Checked the Line Out
AMP signal in/out?
YES
2B
No output Beep sound?
OK
YES
YES
IC401(30), IC601(14)
NO
Checked the
Beep control?
2C
[OPTIONAL]

2-6
CAUTION - Tip for repair
Before exchange power amp IC(TB2931) for no audio problem, you have to check
below list.
1. Check VCC (pin 20, 6) & GND
2. Check input pin 11, 12, 14, 15
3. Check Standby, pin 4
: Follow the below list.
4. Check Mute function, pin 22
: Follow the below list.
5. Check Ripple pin 10.
: Normally it is high (about 10 V)
6. Re-soldering all the pin of IC.
: Prevent crack of solder line.
* Keep changed IC, We request that you send it to HQ.
Stand-by Power Sound Voltage
ON OFF OFF 0 to 1.0
OFF ON ON 2.2 to VCC
Mute Sound Voltage
ON OFF 0 to 1.0
OFF ON 2.2 to VCC
Picture 1) Power IC desc.
5 V
110 620
VCC1 VCC2 TABRipple
C2
+B
C3
C5
9Out1 (+)
11
C1
8
7
PW-GND1
Out1 (−)
IN1
5Out2 (+)
12
C1
2
3
PW-GND2
Out2 (−)
IN2
17 Out3 (+)
15
18
19
PW-GND3
Out3 (−)
IN3
21 Out4 (+)
14
C1
24
23
PW-GND4
Out4 (−)
IN4
13
16
C1
C6
4Stby
25
22 Mute
C4
R1
Play
Mute
RL
RL
RL
RL
Pre-GND
AC-GND
Offset/short

2-7
3. DISPLAY ERROR CORRECTION FLOW CHART
No Display or Some Display is broken?
Something wrong with the Display?
OK
YES
IC901(56)
YES
NO
Checked the LCD
Driver Vdd?
YES
IC901(60)
NO
Checked the LCD
Driver Ground?
YES
IC901(57), IC401(29)
NO
Checked the LCD
Driver RESET?
YES
IC901(61)
NO
Checked the LCD
Driver OSC?
YES
IC401(23, 24, 25, 29),
CN402(9, 10, 16, 18),
IC901(57, 62, 63, 64)
NO
Checked the LCD
Driver data interface?
YES
IC901(1~55),
LCD, Check the short
NO
Checked the LCD to
LCD Driver line?

2-8
4. TUNER ERROR CORRECTION FLOW CHART
Not available to Tuner?
Something wrong with the Tuner system?
OK
YES
IC101(6, 22)
NO
Checked the
Tuner VDD?
YES
IC801(4, 5), IC401(95), D817
NO
Checked the Tuner
VDD control?
YES
IC101(5, 10, 17, 23)
NO
Checked the
Tuner GND?
YES
IC601(15), IC401(98)
NO
Checked the E-VR
Mute control?
YES
IC101(18, 19), IC401(1, 2)
NO
Checked the
I2C data?
YES
IC101(8, 9)
NO
Checked the
Audio signal?
YES

2-9
5. USB ERROR CORRECTION FLOW CHART
Only "NO USB" or "USB CHECK" Display?
Something wrong with the USB?
5A 5B
OK
YES
IC805, IC401(52)
YES
NO
Checked the USB VDD?
YES
IC501(4, 5, 7, 9, 12, 44, 49, 51, 74, 77, 81,
102, 104, 116, 117)
NO
Checked the USB
interface IC GND?
YES
IC401(42), R425
NO
Checked the USB
interface IC reset?
YES
X502
NO
Checked the USB
interface IC X-tal?
YES
IC501(52, 53)
NO
Checked the
D+/D- Port?
YES
IC501(52, 53)
NO
Checked the USB
indication Port?

2-10
"FILE CHECK" Display?
YES
YES
IC501(4, 5, 7, 9, 12, 44, 49, 51, 74, 77, 81,
102, 104, 116, 117)
NO
Checked the CD
DSP GND?
YES
IC401(42), R425
NO
Checked the USB
interface IC reset?
YES
X502
NO
Checked the
DSP X-tal?
IC401(26, 27, 28, 60)
NO
Checked the
DSP control?
YES
5A
USB no sound?
OK
YES
IC501(52, 53)
NO
Checked the CD
DSP signal out?
YES
5B
OK

2-11
6. AUX ERROR CORRECTION FLOW CHART
AUX no sound?
OK
Something wrong with the AUX?
YES
JK903, IC601(7, 9), CN971(19, 20, 21),
CN402(4, 5, 6)
NO
Checked the AUX
Signal input?
YES
See the Sound Error correction Process.
NO
Checked the
E-VR & Power AMP?
YES