LG LAC-M3600R User manual

DETACHABLE FRONT
PANEL CAR CD RECEIVER
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS”
IN THIS MANUAL.
MODEL:LAC-M3600/LAC-M3600R
SERVICE MANUAL MODEL:LAC-M3600/LAC-M3600R

- 1-1 -
[CONTENTS]
❍SECTION 1.GENERAL
• SERVICING PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
• ESD PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
• SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4
❍SECTION 2. ELECTRICAL
• ELECTRICAL TROUBLESHOOTING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
• WAVEFORMS OF MAJOR CHECK POINT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
• INTERNAL BLOCK DIAGRAM of ICs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
• BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17
• SCHEMATIC DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19
• PRINTED CIRCUIT DIARGAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27
❍SECTION 3. EXPLODED VIEWS
• CABINET AND MAIN FRAME SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
• MECHANISM (PICK-UP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
❍SECTION 4. REPLACEMENT PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . .4-1

- 1-2 -
SECTION 1. SUMMARY
❏SERVICING PRECAUTIONS
❶ 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.
❷ Do not defeat any plug/socket B+ voltage interlocks with which instruments covered by
this service manual might be equipped.
❹ Do not apply power to this instrument and or any of its electrical assemblies unless all
solid-state device heat sinks are correctly installed.
❸ 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 replac-
ing any components, use components which have the same ratings. Components marked in the cir-
cuit 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 cor-
rectly 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
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
“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.

- 1-4 -
❏SPECIFICATIONS
1. GENERAL
Power requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DC12V~15V
Ground system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Negative
Dimensions(W x H x D) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 x 58 x 166mm
Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Net: 1.3kg
2. RADIO SECTION
FM AM(MW)
Frequency range 65.0~74.0MHz(Optional), 522~1,620kHz
87.5~108MHz (Optional:530~1,710kHz/ 520~1,620kHz)
Intermediate frequency 10.8MHz 450kHz
Usable sensitivity 10dBµV 28dBµV
Signal to noise ratio 55dB 45dB
3. COMPACT DISC SECTION
Frequency response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40Hz~20kHz
Channel separation (Line out) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90dB (1kHz)
Signal to noise ratio (Line out) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110dB
4. AUDIO SECTION
Maximum output power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50W x 4
Speaker impedance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Ωx 4 or 8Ωx 4
NOTE: The design and specifications are subject to change without notice in the sourse of product
improvement.

- 2-1 -
SECTION 2. ELECTRICAL
❏ELECTRICAL TROUBLESHOOTING GUIDE
1. No Power.
Any Key power on.
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
Is power turnd on?
DISC loading?
Does initial reading occur?
Can disc be played?
Is audio output supplied?
OK
Check audio circuitry.
IC501,IC509, CN503
Check tracking servo circuitry.
Q541, IC501, IC503
Check DISC.
Check focusing circuitry.
Q541, IC501
Check laser circuitry.
Q541, IC501
Check loading supply circuitry.
Q9001, Q902, Q903, Q904, PN503,
IC507, IC506, IC508
Check power supply circuitry.
Q930, Q924, Q919,
Q920, Q921, IC902, pin1

- 2-2 -
2. LCD light abnornal.
YES
YES
YES
YES
YES
YES
NO NO
NO
NO
NO
NO
NO
Any Key power on.
(without DISC)
Do display LCD then light? Check voltage in the power
supply
Power supply circuitry defective.
Q371,Q372,IC403
• Reset circuit defective.
IC901 Surrounding circuit
defective.
X101,X102,C101,
C102,C103,C104.
Q921,ZD910
PCB pattern defective.
IC906,Pin74,75,76
front PCB pattern defective.
IC901,Surrounding circuit
PCB pattern defective.
Display LCD connector
defective.
Is IC901 Com1, Com2, Com3
output waveform normal?
Is u-com IC906 Pin 74,75,76
output waveform normal?
Is u-com IC906 LCD reset
circuit normal?Pin74
Is u-com IC906 keyin
Pin19,20 5volt input?
Is u-com IC906 X1,X2 terminal
Pin11,12,14,15 input?
OSC :19.2MHz
OSC :32.768kHz

- 2-3 -
3. Initial reading is not carried out.
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES (with disc)
NO NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
Slide motor moves
(With disc)
Spindle motor turns
WAVEFORM #1
Does RF waveform
appear? IC501 Pin49
WAVEFORM #2
Check the Voltage change of
CN503 Pin12 (6.4~6.8V)
Check the Voltage IC501
Pin23 (1.4V~1.8V)
Check the Data transmission
from CN503 (16, 17, 18) to CD
DSP WAVEFORM #5
Check the Data transmission
from CN503 Pin21 to MICOM
WAVEFORM #5
Check the TRVP
Voltage
IC501 Pin23
Check the change of
SL +, SL - Voltage
IC503 Pin13,14
Does FA+ waveform appear at
IC501 Pin23?
WAVEFORM #3
Laser light check A ?
focus coil drive wareform.
TRACKING ERROR wareform
Defective contact CN501
Defective PICK-UP
Defective IC503
Defective IC501
Defective
connector CN503
Defective IC503
Defective connector
CN503 Defective
MICOM
Defective IC501
Defective
connector CN503
Does TE waveform appear at
IC501 Pin24?
WAVEFORM #4
Is rotation normal?
Is there no dropout of RF signal?
Defective IC501
Defective PICK-UP

- 2-4 -
When laser does not light.
A
Is “2.4V~3.4V” applied to
pin42 of IC501?
( ➀3.4V ➁2.4V)
Did pickup return to
innermost circular?
Does it stop at inner pick
circular after shift?
Is defect output from LMT
SW applied to Pin7 of
PN503?
Is data transferred from
MICOM IC ?
Does voltage appear at
IC503 Pin 13, 14?
Defective MICOM or CN503.
Defective IC501.
Defective slide motor and/or
connector. (CN502)
Defective LMT SW and/or
connector. (CN502,CN503)
Defective MICOM.
Defective IC501
Is power supplied to laser Q541?
(Q541 collector: about 1.8V)
OV
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
OPEN CLOSE

- 2-5 -
When laser light.
B
When SPINDLE motor dose not turn
C
NO
NO
NO
NO
YES
YES
YES
YES
Laser lights
Check the signal FOCUS
SEARCH of IC501 Pin25
WAVEFORM #3
Check the signal of IC503
Pin 15, 16
WAVEFORM #3 Defective IC501
Defective IC501
Degraded laser diode
Defective PICK-UP
Defective IC501
Defective IC503
Defective contact CN501
or Defective PICK-UP
Check the change for
SP +, SP -, Voltage of
IC503 Pin11, 12
WAVEFORM #1
Check the change for
SPDO Voltage of
IC501 Pin21
WAVEFORM #1

- 2-6 -
❏WAVEFORMS OF MAJOR CHECK POINT
#1. SPINDLE DRIVE AND MOTOR WAVEFORM
IC501(21), IC504(12) during TOC reading
#2. RF WAVEFORM
IC501(45), IC501(49) during TOC reading
#3. FOCUS DRIVE AND MOTOR WAVEFORM
IC501(25), IC503(15)
•When focus search failed or there is no disc on tray
#4. TRACK DRIVE AND MOTOR WAVEFORM
IC504(24), IC503(17) during TOC reading
•There is disc on tray and focus search success

- 2-7 -
❏INTERNAL BLOCK DIAGRAM of ICs
■ AV_CAR
1) Micom Port Assignment

- 2-8 -
2) Pin Descriptions

- 2-9 -

- 2-10 -
■ BD3805F
1) BLOCK DIAGRAM

- 2-11 -
■ MN6627933CN(DSP)
1) Connection Diagram

- 2-12 -
■ TA8275HQ
1) Block Diagram

- 2-13 -
■ upd78f0546(Micom)
1) Block Diagram

- 2-14 -
2) Pin lay out

- 2-15 -
3) Pin Function
PIN NAME Function
VDD Positive power supply except for ports ( except P20-P27 and P121-P124) and AD converter
VSS Ground potential except for ports (except P20-P27 and P121-P124) and AD converter
EVDD Positive power supply for ports (expect p20-p27 and p121-p124)
EVSS Ground potential for ports (except p20-p27 and p121-p124)
RESET System reset input
FLMDO Flash EEPROM programming mode setting
REGC Connecting regulator stabillzation capacitor. Connect to GND via a capacitor (0.47µF).
AVREF A/D converter analog power supply and power supply for p20-p27
AVSS Ground potential for A/D convert and p20-p27
P00/T1000 I/O port
External count clock input to 16-bit timer/event counter 00
Capture trigger input to capture reglsters (CR000, CR010) of 16-bit timer/event counter 00(TM00)
P01/TI010/TO00 I/O port
Capture trigger input to capture register (CR000) of 16-bit timer/event counter 00 (TM00)
16-bit timer/event counter 00 outout (TM00)
P02/SO11 I/O port
Serial data output from serial interface (CSI11)
PO3/SI11 I/O port
Serial data input to serial interface (CSI11)
P20/SCK11 I/O port
Clock input/output for serial interface (CSI11)
P05/TI001/SSI11 I/O port
External count clock input to 18-bit timer/event counter 01
Capture trigger input to capture reglsters (CR001, CR011) of 16-bit timer/event counter 01( TM01)
Chip input/output for serial interface (CSI11)
P06/TI011/TO01 I/O port
Capture trigger input to capture register (CR001) of 160bit timer/evrnt counter 01 (TM01)
16-bit timer/evrnt counter 01 output (TM01)
P10/SCK10/TXD0 I/O port
Clock input/output for serial interface (CSI10)
Serial data output from asynchronous serial interface (UART0)
P11/SI10/RXD0 I/O port
Serial data input to serial interface (CSI10)
Serial data input to asynchronous serial interface (UART0)
P12/SO10 I/O port
Serial data input to serial interface (CSI10)
P13/TXD6 I/O port
Serial data output from asynchronous serial interface (UART6)
P14.RXD6 I/O port
Serial data input to asynchronous serial interface (UART6)
P15/TOH0 I/O port
8-bit timer H0 output (TMH0)
P16/TOH1/NTP5 I/O port
8-bit timer H1 output (TMH1)
External interrupt request input with specifiable valia edges
P17/TI50/TO50 I/O port
External count clock input to 8-bit timer/event counter 50 (TM50)
8-bit timer/event counter 50 output (TM50)
P20-P27/ANI0-ANI7 I/O ports
A/D converter analog input
P30/INTP1 I/O port
P31/INTP2 External interrupt request input with specifiable vaild edges
P31/INTP2
P33 I/O port
/TI51 External count clock input to 8-bit time/event counter 51 (TM51)
/TO51 8-bit timer/event counter 51 output (TM51)
/INTP4 External interrupt request input with specifiable valid edges
P40-P47 I/O port
P50-P57 I/O port
P60/SCL0 I/O port (N-ch open drain)
Clock input/output for serial interface (IIC0)
P61/SDA0 I/O port (N-ch open drain)
Serial data input/output for serial interface (IIC0)