LG TCH-M1000 User manual

- 1-1 -
❍SECTION 1. SUMMARY
• SERVICING PRECAUTIONS .......................................................................................................... 1-2
• ESD PRECAUTIONS....................................................................................................................... 1-3
• SPECIFICATIONS........................................................................................................................... 1-4
❍SECTION 2. ELECTRICAL
• ELECTRICAL TROUBLESHOOTING GUIDE ................................................................................. 2-1
• CD PART TROUBLESHOOTING GUIDE......................................................................................... 2-3
• WAVEFORMS OF MAJOR CHECK POINT .................................................................................. 2-11
• INTERNAL BLOCK DIAGRAM of ICs............................................................................................ 2-13
• BLOCK DIAGRAM......................................................................................................................... 2-25
• SCHEMATIC DIAGRAM................................................................................................................ 2-27
• MAIN SCHEMATIC DIAGRAM...................................................................................................... 2-29
• CDP SCHEMATIC DIAGRAM ....................................................................................................... 2-31
• PRINTED CIRCUIT DIAGRAM...................................................................................................... 2-33
❍SECTION 3. CABINET MAIN CHASSIS & MECHANISM
• EXPLODED VIEW ........................................................................................................................... 3-1
❍SECTION 4. REPLACEMENT PARTS LIST.................................................................... 4-1
[CONTENTS]

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❏SERVICING PRECAUTIONS
➊Always 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.
➋Do not defeat any plug/socket B+ voltage interlocks with which instruments covered by this service
manual might be equipped.
❸Do not apply power to this instrument and or any of its electrical assemblies unless all solid-state
device heat sinks are correctly installed.
❹Always 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.
SECTION 1. SUMMARY

- 1-3 -
❏ESD PRECAUTIONS
[Electrostatically Sensitive Devices (ESD)]
Some semiconductor (solid state) devices can be damaged easily by static electricity. Such omponents
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 material).
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 be installed.
CAUTION: Be sure no power is applied to the chassis or circuit, and observe all other safety precautions.
8) Minimize bodily motions when handling 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.

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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 12dBµV 32dBµV
Signal to noise ratio 55dB 45dB
3. COMPACT DISC SECTION
Frequency response..................................................................................................................... 40Hz~20kHz
Channel separation ...................................................................................................................... 50dB(1kHz)
Signal to noise ratio .................................................................................................................................. 60dB
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.
❏SPECIFICATIONS

- 2-1 -
SECTION 2. ELECTRICAL
❏ELECTRICAL TROUBLESHOOTING GUIDE
Any Key power on.
Is power turnd on?
DISC loading?
Does initial reading occur?
Can disc be played?
Is audio output supplied?
Check power supply circuitry.
Q260, Q380, Q381, IC401 Pin76
IC201 Pin2
Check loading supply circuitry.
Q350,Q351,PN505, IC401 Pin27
Check laser circuitry.
Q501, IC502
Check focusing circuitry.
Q501,IC502
Check DISC.
Check tracking servo circuitry.
Q501,IC502
Check audio circuitry.
IC502,IC601,IC801
OK
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
(1) No Power.

- 2-2 -
YES
YES
YES
YES
YES
YES
(2) LCD light abnornal.
Any Key power on.
(without DISC)
Do display LCD then light? Check voltage in the power
supply circuitry.
Power supply circuitry
defective.
Q380,Q381,IC403
Reset circuit defective.
IC201 Surrounding circuit
defective.
X401, C413,C414 defective.
Q260, PN401 front PCB
pattern defective.
IC401, Pin38, 40, 47, 48 front
PCB pattern defective.
IC901, Surrounding circuit
PCB pattern defective.
Is u-com IC401 reset circuit
normal? Pin10
Is u-com IC401 keyin Pin16, 44
71 5volt input?
Is u-com IC401 Pin 38,40,47,48
output waveform normal?
Is IC901 Com1, Com2, Com3
output waveform normal?
Display LCD connector defective.
Is u-com IC401X1, X2 terminal
Pin14, 15 input?
OSC : 9.8304MHz
NO NO
NO
NO
NO
NO
NO

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- 2-4 -

- 2-5 -

- 2-6 -

- 2-7 -

- 2-8 -

- 2-9 -

- 2-10 -

- 2-11 -
❏WAVEFORMS OF MAJOR CHECK POINT
#1. MICOM INTERFACE WAVEFORM
(CN503 1 9,2 1 ,1 8,20) during normal play
#2. SLED DRIVE AND MOTOR WAVEFORM
(IC504 pin5, 1 4) when focus search
#3. FOCUS DRIVE AND MOTOR WAVEFORM
(R5 1 3, IC504 pin 1 5)
•When focus search failed or there is no disc on the
tray
•There is disc on tray and focus search success

- 2-12 -
#4. SPINDLE DRIVE AND MOTOR WAVEFORM
(IC504 pin6, 1 2) when TOC reading
#5. TRACK DRIVE AND MOTOR WAVEFORM
(R508, IC504 pin23) during normal play
#6. RF, TRACKING AND FOCUS ERROR WAVEFORM
(IC502 pin8, 2 1 , 23) during normal play

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■IC401 LC875465B
1) PORT ASSIGNMENT
❏INTERNAL BLOCK DIAGRAM of ICs

- 2-14 -
2) PORT DESCRIPTION

- 2-15 -
Pin I/O
26 I
27 O
28 O
29 O
30 O
31 I
32 O
33 O
34 O
35 I
36 O
37 O
38 O
39 I
40 O
41 I
42 O
43 O
44 -
45 -
46 O
47 O
48 O
49 O
50 O
51 O
52 O
53 O
54 I
55 O
56 I
57 I
58 I
59 I
60 O
61 O
62 O
63 I
64 I
65 I
66 O
67 I
68 O
69 I
70 -
71 -
72 I
P34
P33
PCD_MUTE CD s audio signal ute output
PDSP_ODA
In MD, otor driver s power save co and ouput
Power Save Mode(High), Nor al Mode(Low)
In MD, all otor s output "cut off" co and ouput
Cut Off Mode(High), Nor al Mode(Low)
Constant velocity signal input
Ok(High), Not Ok(Low)
DSP chip enable output
In MD, load otor "forward" co and output
To DSP, data output
Fro DSP, data input
Clock output for interface with DSP
In MD, SW2 state input. Refer to CD Player.
DSP power suppler ON ouptut
Description
Beep sound (2KHz) output
To LCD driver, data output
Not to be used
Clock output for interface with LCD driver
Not to be used
Not to be used
Not to be used
Power supply (+5V)
Ground
PLL IC enable output
LCD driver enable output
LCD driver reset output
Nor al(High), Reset(Low)
External a plifier ON output
LED flashing control output
Not to be used
Not to be used
Not to be used
Focusing OK signal input
Ok(High), Not Ok(Low)
DSP reset output
Not to be used
Not to be used
Not to be used
Not to be used
To CD changer, data output
For diode option check, signal 1 output. Refer to Option Diode.
For diode option check, signal 2 output. Refer to Option Diode.
For diode option check, signal 1 or 2 input2. Refer to Option Diode.
For diode option check, signal 1 or 2 input1. Refer to Option Diode.
For diode option check, signal 1 or 2 input0. Refer to Option Diode.
Clock output for interface with PLL IC
Fro PLL IC, data input
To PLL IC, data output
Telephone ute input
Ground
Power supply (+5V)
Not to be used
P32
PCD_FWD
Name in ModelName in Micom
PCD_SW2P31
PCD_PWR
P10/SO0
PDSP_IDAP11/SI0/SB0
PDSP_OCLKP12/SCK0
PDRV_OPSP13/SO1
PDRV_OMUTEP14/SI1/SB1
PDSP_IFSEQP15/SCK1
PDSP_OCENP16/T1PWML
PBEEP
P17/T1PWMH/BU
Z
PFRT_DOSI2P0/SO2
N.CSI2P1/SI2/SB2
PFRT_CLKSI2P2/SCK2
N.CSI2P3/SCK20
N.CPWM1
N.CPWM0
VDDVDD2
GNDVSS2
PPLL_CEP00
PFRT_CEP01
PFRT_RESP02
PREMOTEP03
PLEDP04
N.CP05
N.CP06
N.CP07
PDSP_IDRFP20/INT4/T1IN
PDSP_IRSTP21/INT4/T1IN
N.CP22/INT4/T1IN
N.CP23/INT4/T1IN
N.CP24/INT5/T1IN
N.CP25/INT5/T1IN
PCDC_DOP26/INT5/T1IN
POPT_OUT0P27/INT5/T1IN
POPT_OUT1PB7/D7
POPT_IN2PB6/D6
POPT_IN1PB5/D5
POPT_IN0PB4/D4
PPLL_CLKPB3/D3
PPLL_DIPB2/D2
PPLL_DOPB1/D1
PTEL_MUTEPB0/D0
GNDVSS3
VDDVDD3
N.CPC7/A7
ForwardLowHi
g
h
Break modeHi
g
hHi
g
h
ReverseHi
g
hLow
O
p
en modeLowLow
FunctionPCD
_
RPCD
_F
’
’
’

- 2-16 -
■IC501 MN6627933
1) PORT ASSIGNMENT
Pin I /O
73 O
74 O
75 O
76 O
77 I
78 I
79 O
80 I
PC0/A0
PA0/CS2#
PC4/A4
PC3/A3
PC2/A2
PC1/A1
PFRT_DET
Front pannel existence signal input
Front Pannel Ok(High), Absent(Low)
Clock for interface with volume controller
System Power supplier ON output
On(High), Off(Low)
Description
To volume controller, data output
To power amp, "MUTE" command output
Mute(High), Sound(Low)
Name in Micom
PPWR_MUTEPC6/A6
PEV_CLKPC5/A5
PPWR
Name in Model
PEV_DO
From ISO jack, ACC signal input
ACC On(Low), ACC Off(High)
Not to beused
CD changer power supplier ON output
CDC On(High), CDC Off(Low)
PACC
N.C
PCDC_PWR