LG FFH-164 User manual

- 1-1 -
CONTENTS
SECTION 1. GENERAL
•SERVICING PRECAUTIONS ....................................................................................................................... 1-2
• ESD PRECAUTIONS................................................................................................................................... 1-4
• SPECIFICATIONS ....................................................................................................................................... 1-5
SECTION 2. ELECTRICAL
• ADJUSTMENTS........................................................................................................................................... 2-1
• TROUBLESHOOTING ................................................................................................................................. 2-3
• WAVEFORMS OF MAJOR CHECK POINT ................................................................................................ 2-6
• BLOCK DIAGRAM ..................................................................................................................................... 2-15
• SCHEMATIC DIAGRAMS.......................................................................................................................... 2-17
• WIRING DIAGRAM ......................................................................................................................................2-25
• PRINTED CIRCUIT DIARGAMS................................................................................................................ 2-27
• INTERNAL BLOCK DIAGRAM OF IC’s ..................................................................................................... 2-37
SECTION 3. EXPLODED VIEWS
• CABINET AND MAIN FRAME SECTION ................................................................................................... 3-1
• TAPE DECK MECHANISM: AUTO STOP DECK ......................................................................................... 3-3
SECTION 4. SPEAKER .................................................................................................................. 4-1
SECTION 5. REPLACEMENT PARTS LIST .................................................................................. 5-1

SECTION 1. GENERAL
SERVICING PRECAUTIONS
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 this.
6) Never attempt to disassemble the pick-up.
Spring by 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.
- 1-2 -
Storage in conductive bag Drop impact
NEVER look directly at the laser beam, and don’t let
contact fingers or other exposed skin.
Magnet
How to hold the pick-up
Pressure
Pressure
Cotton swab
Conductive Sheet

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 of humidity is high, where strong
magnetism 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 (1MΩ)
6) Care should be taken not to permit the laser pick-up to come in contact with clothing, in order to prevent
static 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.
CLEARING MALFUNCTION
You can reset your unit to initial status if malfunction occur(button malfunction, display, etc.).
Using a pointed good conductor(such as driver), simply short the RESET jump wire on the inside of the
volume knob for more than 3 seconds.
If you reset your unit, you must reenter all its settings(stations, clock, timer)
NOTE: 1. To operate the RESET jump wire, pull the volume rotary knob and release it.
2. If you wish to operate the RESET jump wire, it is necessary to unplug the power cord.
- 1-3 -
Armband
Conductive
Sheet
Resistor
(1 Mohm)
Resistor
(1 Mohm)
VOLUME KNOB
UP
DOWN
VOLUME
RESET jump wire

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
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.
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SPECIFICATIONS
- 1-5 -
NOTE : Specification are subject to change without notice in the course of product improvement.
SECTION MODEL FFH-164, 165
General Power supply Refer to the back panel of the unit
Power consumption 20W
Mass 3.44kg
Extemal dimensions(W X H X D) 161 X 249 X 271mm
CD Frequency Response 40-18000Hz
Signal-to-noise ratio 60dB
Dynamic range 60dB
Tuning Range 87.5-108.0MHz or 65-74MHz, 87.5-108.0MHz
Intermediate Frequency 10.7 MHz
FM Signal-to-noise ratio 60/55dB
Frequency Response 60-10000Hz
Tuning Range 522-1611kHz or 530-1610kHz
AM Intermediate Frequency 450kHz
Signal-to-noise ratio 35dB
Frequency Response 100 -1800 Hz
AMP Output Power 5W + 5W
T.H.D 0.3%
Frequency Response 42-25000Hz
Signal-to-noise ratio 60dB
TAPE Tape Speed 3000 Hz
Wow Flutter 0.25% (MTT-111,JIS-WTD)
F.F/REW Time 120sec(C-60)
Frequency Response 250-8000Hz
Signal-to-noise ratio 43dB
Channel Separation 50dB(P/B)/45dB(R/P)
Erase Ratio 55dB (MTT-5511)
Speaker MODEL FE-164E 165E
Type 1 way 1 speaker
Impedance 4Ω
Frequency Response 80-20000Hz
Sound Pressure Level 86dB/W(1m)
Rated Input Power 5W
Max.Input Power 10W
Net Dimension(W XH XD) 150 X255 X 175mm
Net Weight 1.52kg
TUNER

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MEMO

- 2-1 -
TAPE DECK ADJUSTMENT
1. AZIMUTH ADJUSTMENT
Figure 1. Azimuth Adjustment Connection Diagram
CH1 CH2
Speaker Out
Playback Mode
Head
Test Tape
MTT-114
L ch
R ch GND
Dual-trace
synchroscope
Electronic
Voltmeter
L out
R out
Unit
SECTION 2. ELECTRICAL
ADJUSTMENTS
This set has been aligned at the factory and normally will not require further adjustment. As a result, it is not
recommended that any attempt is made to modificate any circuit. If any parts are replaced or if anyone tampers
with the adjustment, realignment may be necessary.
IMPORTANT
1. Check Power-source voltage.
2. Set the function switch to band being aligned.
3. Turn volume control to minimum unless otherwise noted.
4. Connect low side of signal source and output indicator to chassis ground unless otherwise specified.
5. Keep the signal input as low as possible to avoid AGC and AC action.
Deck Mode Test Tape Test Point Adjustment Adjust for
Palyback MTT-114 Speaker Out DECK Screw Maximum
Azimuth Screw
2. TUNER ADJUSTMENT
Figure 2. Tuner(S curve) Adjustment Connection Diagram
Unit
Signal Generator
GND
Electronic
OSCILLOSCOPE
FM Antenna
Terminal Speaker
Item Test Point Adjustment Adjust for
DC Voltage Check Point TP1, TP2 L4 0V±50mV
(FM)

- 2-2 -
TROUBLESHOOTING
Turn power on.
Is power on?
Does initial read work?
Does it play?
Does it output audio?
Check power supply circuit.
PN508 PIN 8, 6.2V
PN508 PIN 7, 5V
IC503 PIN 2, 3.3V
Check the connector
PN502, PN503, PN507
Check the tracking servo circuit.
Check the PN508 PIN1, 3
OK
YES
YES
YES
YES
YES
YES
YES
YES
NO
NONO Check the DISK turns
Check the Laser
Check the focus circuit
Check the TRAKING circuit
NO
NO

- 2-3 -
Fails to initial read
A
B
2V
5V
0V
5V
0V
1V
2V
1.2V
0V
0.8V
NO NO
NO
NO
NO
NO
NO
NO
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
Disc motor turns
Does RF waveform appear?
IC501 Pin3
Check the Data transmission from
PN507 pin8 to CD DSP
Check the Data transmission from
PN507 pin6 to MICOM
Check the change of SLDO
Voltage(IC501 pin23)
Check the change of SL +,
SL - Voltage
(IC502 pin 18, 19)
Check the Voltage change of PN 507
pin2(OPEN, CLOSE)
Defective connector
PN507
Defective connector
PN507 Defective
MICOM
Defective connector
PN507 Defective
IC501
Defective IC501
Defective IC502
Defective contact PN503
Defective PICK-UP
Does laser light?
focus coil drive wareform.
TRACKING ERROR wareform
Is rotation normal?
Defective IC501
Defective PICK-UP
IS there no dropout of RF signal?
Does FA+ waveform appear at
IC502 pin13?
Does TE waveform appear at
501 pin 15?

- 2-4 -
NO
NO
NO
NO
NO
NO
Laser does not light.
Is “3.5V” applied to pin of IC 501?
Is power supplied to laser Q501?
(Q 501 collector: about 1.8V)
Does laser current flow?
1.0V across R507
Is data transferred from
MICOM IC ?
Does voltage appear at IC
502 pin , ?
Defective MICOM.
Defective MICOM.
Defective connector.
Defective IC 501, 502
Defective slide motor and/or
connector.
Defective LMT SW and/or
connector.
Defective Q 501 and/or laser.
Defective laser and/or
connector.
Did pickup return to
innermost circular?
Does it stop at inner pick
circular after shift?
Is defect output from LM
SW applied to pin of
PN503?
R507»1.0V
R507«1.0V
YES
YES
YES
YES
OPEN CLOSE
YES
YES
YES
YES
YES
YES
70
17 18
5

- 2-5 -
B
NO
NO
NO
NO
NO
YES
YES
YES
YES
Laser lights
Does lens move up/down? Check the signal of
FOCUS SEARCH
(IC501 Pin 21)
Chekc the signal of PN502
pin 13, 14
Does FE signal appear?
(IC501 pin 13)
Does DRF signal appear? (IC 501 pin67)
Defective IC501
Defective IC502
Open activator and/or connector
Defective IC501
Degraded laser diode
Defective PICK-UP

- 2-6 -
(CH1)
(CH2)
WAVEFORMS OF MAJOR CHECK POINT
1. HF signal (RF signal ) waveform
(IC501 pin 3) during normal play
2. EFM signal (IC501 pin 3)waveform
during Normal Play
3. Focus coil drive waveform(IC502 pin13)
• When focus search failed or there is no disc on the tray
• Focus coil drive waveform(FDO: IC501 pin21) and
DRF(IC501 pin67) when focus search is accomplished
4. Tracking coil drive waveform and TE during track
traverse
(1) When time division is 20mS/Div.1V/Div. (2) When time division 1mS/Div, 1V/Div
(During forward track traverse)
(3) When time division is 0.5nS/div.
(During backward Track Traverse)
5. Feed motor drive waveform(IC 502 pin18)
During normal play
CH1 : FOCUS COIL DRIVE
SIGNAL 2V/Div.
CH2 : DRF
CH1 : TRACKING COIL DRIVE
SIGNAL 2V/Div. (IC502 pin27)
CH2 : TRACKING ERROR(TE: IC501 pin15)
1V/Div.
(
(
(
CH2 : TRACKING COIL DRIVE (IC502 pin27)
SIGNAL 2V/Div.
CH2 : TRACKING ERROR (TE: IC501 pin15)
1V/Div.
(
CH1 : TRACKING COIL DRIVE (IC502 pin27)
CH2 : TRACKING ERROR (TE: IC501 pin15)
(
0.5V/Div.
500nS/Div.
(
1S/Div.
1V/Div.
(
1mS/Div.
1V/Div.
(
0.5V/Div.
5µS/Div.
(
2S/Div.
0.5V/Div.
OV
OV
OV
(CH1)
(CH2)
(CH1)
(CH2)
(CH2)
OV
OV
OV
OV
OV
OV
OV
OV
OV

- 2-7 -
P-SENS PART
Does +5V appear at
ZD205(+)?
Check the pattern of
IC601 Pin .
Check the waveform
of D212 (+).
Check the and
replace ZD205.
Replace the D212
YES
YES
NO
NO
26
Power Circuit
Check the Fuse
Check the DC output
of C299(+)
Check the DC 12V
Output of IC204
Check the DC 6.2V
output of IC202
Check the DC 12V
Output of IC203
Check the 5.0V of Q207 “C”
(CD FUNCTION)
END
Replace the Fuse
Check the AC output of H202 pin 1, 4
Check the AC output of
H202 pin 1, 4
Replace the Q203
Replace the D208, D209,
D210, D211
Check or Replace the
D208,D209, D210, D211.
Check or Replace the
D203, D205
Check the “High” of
Q202 “B”
Check the “High” of Q208
Replace the Q207
Replace the Transformer
Replace the Transformer
Check the “High” of
CN203 Pin 11
Check the “High” of
CN203 Pin 8
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO

- 2-8 -
Muting circuit (MUTE)
Dose “High” appear at
Q301, Q351“B”
check the “Low” of Q301,
Q351 “C”
MUTE
Check the “High” of CN203 PIN 12
Check the “High” of the IC601 Pin9
Replace the TR.
YES
YES
NO
NO
Audio abnormal
Check the output of
IC301 Pin8, 12
Check the connecting to
SPEAKER
Check the “High” of IC301 pin5
Check the input terminal of
Function
OK
Check the input of
IC301 Pin2, 4
Check the DC10V of IC201
pin24
Check the DC 12V Output of
IC204
Check the power
YES
YES
YES
YES
NO
NO
NO
NO

- 2-9 -
FUNCTION MODE Audio abnormal
TAPE
Check the signal input of IC201 pin 3, 24
Refer to “IC100 Troubleshooting”
AUX
Chekc the signal input of IC201, pin 2, 5
Check the signal input of JK201
Check the signal input of IC201 pin 7, 28
Check the signal of PN201 pin 6, 8 or
Refer to “CD Troubleshooting”
Check the signal input of IC201 pin 1, 6
Refer to “IC1 Troubleshooting”
CD
Tuner

- 2-10 -
Refer to “IC601
Troubleshooting”
IC601 Troubleshooting
IC201 Troubleshooting
Check the power supplying IC601 Pin 17, 54, 80, 90?
Refer to “Power Circuit Troubleshooting”
Check the P-SENS
Replace the X602
Check the RESET circuit
Refer to “Power Circuit Troubleshooting”
Check the Data of IC601 Pin 3, 4
(CD ➞ TAPE FUNCTION)
Replace the
IC201
Check the pattern
of (IC601 & IC201)
Check the P-SENS “High” of IC601 pin 26
Check the oscillation of X602
When power supplying to IC601 pin11.
(Low ➞ High)
Replace the IC601
Check the power supplying to IC201 pin24
Check the CLK Data of IC201 pin 21, 22
Check the CONTROLL function
END
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO

- 2-11 -
FM (TUN1)
Check the +12V input of TUN1 B+ 6
Check the “High” Voltage of TUN1 VT 5
Check the OSC waveform of TUN1 Pin 8
Refer to “IC1 Troubleshooting”
Check the 12V of Q2 “E”
Refer to “Power
Circuit Trouble-
shooting”
Check the “LOW” of IC2 Pin 7
Refer to “IC2
Troubleshooting”
Replace the Q2
Replace the TUN1
Replace the TUN1
YES
YES
YES
YES
YES
NO
NO
IC1 Troubleshooting
Check the power supplying to pin8
Check the waveform of Pin 20, 21
Check the waveform output of Pin 16, 17
END
Refer to “Power Circuit
Troubleshooting”
Check the FM(TUN1) & AM(L2)
Replace the IC1
Replace the IC2
Check the “Low” of Pin 13
Refer to “IC2
Troubleshooting”
YES
YES
YES
YES
NO
NO
NO
NO
NO

- 2-12 -
IC2 Troubleshooting
Check the power supplying to pin 17
Check the oscillation of X1
Check the clock of CE, DI, DO, CLK
Is the normal ?
END
Refer to “Power Circuit
Troubleshooting”
Replace the X1
Check the line or refer to “IC2
Troubleshooting”
CE: Chip Enable
DI: Data Input(from u-com)
DO: Data Output(to u-com)
CLK: Tuner mode clock
Replace the IC2
YES
YES
YES
YES
NO
NO
NO
NO
AM•COIL Troubleshooting
Check the “High” of L2 Pin 2
Refer to “IC2 Troubleshooting”
Replace the L2
Check the oscillation of L2 Pin 13
Refer to “IC1 Troubleshooting”
YES
YES
NO
NO
Play
Check the VCC supplying to IC100 pin 4
Refer to “Power Circuit Troubleshooting”
Check the Deck Mecha
Replace the Deck
Mecha.
Replace the IC100
Check the signal output of IC100 pin 3, 6
Check the “LOW” of Q100, 150, “B”
YES
YES
YES
NO
NO
NO

- 2-13 -
REC
Check signal supplied to IC101 pin 2, 8 ?
Check the output of IC101 Pin3, 7
Check the “High” of IC101 pin 6
Check the power or Refer to “IC101
Troubleshooting”
Check the power
supplying to C138(+)
Check the oscillation of
Q103, “E”
Check the 0.6V of
Q103 “B”
END
Check the Vcc power of IC101 Pin6
Check the oscillation of L100 pin 1, 3
Replace the DECK
Check the “Low” of Q109,
Q159 “B”
Replace the Q109, Q159
Refer to “IC101
Troubleshooting”
Refer to “Power Circuit
Troubleshooting”
Check the 1.0V of
R130
Check the L100
YES
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
NO

- 2-14 -
MEMO