LG FFH-2103 SERVICE MANUAL

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CONTENTS

1. SERVICING PRECAUTIONS

......................................................................................................................

2. ESD PRECAUTIONS

..................................................................................................................................

3. SPECIFICATIONS

......................................................................................................................................

4. ADJUSTMENTS

..........................................................................................................................................

5. TROUBLESHOOTING GUIDE

..................................................................................................................

6. WAVEFORMS OF MAJOR CHECK POINT

..............................................................................................

7. BLOCK DIAGRAM

....................................................................................................................................

8. SCHEMATIC DIAGRAMS

.........................................................................................................................

9. WIRING DIAGRAM

...................................................................................................................................

10. PCB LAYOUTS

.........................................................................................................................................

11. INTERNAL BLOCK DIAGRAM OF ICs

.....................................................................................................

12. REPAIRS REGARDING CD MECHANISM

...............................................................................................

13. EXPLODED VIEW/PARTS LIST(CABINET/TAPE DECK MECHANISM/CD/PICK-UP)

...........................

14. SPEAKER EXPLODED VIEW/PARTS LIST

.............................................................................................

15. REPLACEMENT PARTS LIST

..................................................................................................................

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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.

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

Cotton swab

Conductive Sheet

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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.

Armband

Conductive Sheet

Resistor (1 Mohm)

VOLUME KNOB

DOWN

VOLUME

RESET jump wire

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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. AMP SECTION

1) Power Output (6 Ω, 2 channel, T.H.D. 10%) F-2103-30W+30W F-2108-75W+75W

2) T.H.D 0.2%

3) Frequency Response (-3dB down) 40Hz~25kHz

4) Signal-to-noise Ratio 80dB

5) Input Sensitivity AUX 400±50mV

6) Channel Difference 1kHz 2dB

2. TUNER SECTION

1) FM/OIRT

1) Frequency Range 87.5MHz~108MHz

or 65.0MHz~74.0MHz & 87.5MHz~108MHz

2) Intermediate Frequency 10.7MHz

3) Sensitivity (69MHz/70MHz/71MHz/90.1MHz/98.1MHz/106.1MHz) 12dB

4) Signal-to-noise Ratio 98.1MHz(Mono/Stereo) 61dB/58dB

5) Image Rejection 106.1MHz 20dB

6) IF Rejection 90.1MHz 65dB

7) Distortion 98.1MHz(Mono/Stereo) 1.2%

8) Frequency Response (-3dB) 60Hz~12.5kHz

9) Stereo Separation (100Hz/1kHz/10kHz) 23dB

2) AM(MW)

1) Frequency Range 522kHz~1611kHz

2) Intermediate Frequency 455kHz

3) Usable Sensitivity 55dB

4) Image Rejection (1404kHz) 25dB

5) IF Rejection (603kHz) 40dB

6) Selectivity (1008kHz) ±23dB

7) Signal-to-noise Ratio (1008kHz) 35dB

8) Distortion (1008kHz) 1.5%

9) Frequency Response (1008kHz) 100Hz~2000Hz

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3. TAPE DECK SECTION

1) Tape Speed (MTT-111) / Normal Speed 4.75(+2%/-1%) cm/sec

2) Wow Flutter (MTT-111) 0.25%

3) Fast Forward and Rewind Time (C-60) 120sec

4) Frequency Response (6dB range) 125Hz~8kHz

5) Signal-to-noise Ratio (Playback/Record) 43dB/43dB

6) Distortion (Playback/Record) 3% / 4%

7) Crosstalk (Playback: 1kHz) 55dB

8) Channel Separation (Playback: 1kHz) 45dB

9) Erase Ratio 55dB

4. COMPACT DISC PLAYER SECTION

1) Frequency Response (40Hz-18kHz) +0.5/-3.0dB

2) Signal-to-noise Ratio (1kHz) 70dB

3) Dynamic Range (1kHz) 70dB

4) T.H.D. (1kHz) 0.2%

5) Separation (100Hz/1kHz/10kHz) 45dB/45dB/40dB

6) Access Time Short / Long 2sec/6sec

5. VIDEO SECTION

1) Output Level 1Vp-p

6. GENERAL

1) Power requirement Refer to the back panel of unit

2) Power consumption F2103-80W F2108-90W

3) Dimension (W x H x D) 273 x 330 x 360 (mm)

4) Weight (net) 8.0kg

NOTE : specification are subject to change without notice in the course of product improvement.

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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.

TAPE DECK ADJUSTMENT

1. AZIMUTH ADJUSTMENT

Figure 2. 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

Deck Mode Test Tape Test Point Adjustment Adjust for

A Deck Playback MTT-114 Speaker Out Azimuth Screw Maximum

B Deck Playback MTT-114 Speaker Out Azimuth Screw Maximum

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2. MOTOR SPEED ADJUSTMENT

Figure 3. Motor Speed Adjustment Connection Diagram

Deck Mode Test Tape Test Point Adjustment Adjust for Remark

Normal Speed MTT-111 Speaker Out VR401 3kHz ± 1% A Deck

HI-Speed MTT-111 Speaker Out more than 5.4kHz HI-Speed Dubbing Mode

3. RECORD BIAS ADJUSTMENT

Head

Unit

PN402

GND

Record/Playback head

Test Tape MTT-5511

Record/Playback and Pause Mode

Frequency Counter

Deck Mode Test Tape Test Point Adjustment Adjust for

Rec/Pause MTT-5511 PN402 L403 90kHz±5kHz

Figure 4. Record Bias Adjustment Connection Diagram

Head

Test Tape MTT-111

Record/Playback head

Playback Mode

L out

Unit

R out

Speaker Out

GND

Frequency Counter

TROUBLESHOOTING GUIDE

1. POWER PART

Turn power on.

PN302 5.6V check?

PN302 Defective.

IC703 Surrounding circuitry defective.

IC703 defective.

IC301 defective.

IC801 defective.

IC301 defective.

•

PN808 defective.

•

Pattern defective.

•

X301 defective.

•

IC301 defective.

IC301 16, 46, 72, 90 input +5V

IC703 check?

• Pin 1 + 12V

• Pin 3 + 6.3V

IC301 Pin 79 power output?

IC301 Pin 97 HRST output?

IC801 Pin 13,15,17,4 Check?

IC301 Pin 12 Reset check.

IC301 Pin 98,99,100,97 Check?

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OFF

ON 5V

PCTL

HRST

13 15

98 99

100

NO NO

YES

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2. CD PART

DOOR OPEN/CLOSE

CHECK? (LOADING)

Is rotate turret?

(A) When laser does not light.

(B) When laser lights.

Is DISC play?

Is lead-in?

Is audio output?

2-1

2-2

2-3

2-4

2-5

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2-1. DOOR OPEN/CLOSE PART(LOADING)

Door open/close?

IC809 Pin 2, 10 Output?

• ZD803 defective.

• +12V-CD defective.

•

IC809 defective.

•

2,10 pattern defective.

Pick-up MOTOR? Pick-up defective.

• CLOSE leaf s/w defective.

• IC801 Pin 2, 3 defective.

• ZD803 (4.7V)?

• IC809 surrounding circuitry check?

IC809 Pin 5,6 input?

OPEN L H

CLOSE H L

YES

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2-2. TURRET PART

Is Rotation turret?

Limit S/W 0V(LOW) check?

IC801 Pin 47, 51, 93, 94 check?

IC808 Pin 15, 16, output check?

PN802 input check?

Pick-up check?

Pick-up defective.

IC808 Pin 11, 12 output pattern defective.

PN805 connector check.

IC801 DATA, CLK, XLT check?

IC801 defective.

•

IC801 Pin 20, 21, 23 Pattern defective.

•

IC827 defective.

•

IC827 X-TAL Pin 8, 9 defective.

IC827 36, 37, 38 check?

IC806 Pin 43 output check?

IC808 Pin 11, 12 output check?

• IC808 Pin 10 pattern defective.

• IC806 defective.

Down leaf S/W(PN804) 0V (LOW) check?

leaf S/W defective.

• IC801 defective.

• IC801 Pin 47, 51, 93, 94 pattern defective.

• IC806 Pin 35, 36, 37 input defective.

• IC806 defective.

• IC808 defective.

• IC808 Pin 9, 14 input defective.

• IC808 Pin 15, 16, output defective.

NO NO

YES

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2-3. DISC PLAY PART(A, B)

(A) When laser does not light.

IC806 Pin 72 2.8V(LD) check?

•

IC806 defective.

•

IC806 Pin 71 defective.

•

Q801 defective.

•

R833 defective.

PN801 defective.

Pick-up defective.

Q801 Collector 2.0V?

PN801 check?

Pick-up lens check?

YES

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(B) When laser lights

(C)

Does the lens move up and

down?

IC806 Pin 48 output (FEO)?

•

IC806 defective.

•

C811 defective.

•

IC806 Pin 25 input defective.

•

IC806 defective.

•

PN801 defective.

•

Pick-up defective.

IC806 Pin 26, 27 output check?

IC806 Pin 79 RFO output?

Q801 defective.

NO NO

YES

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(C)

The wavefrom of IC806 Pin 79 is below figure?

IC806 “FOK” signal output? (Pin 40 check?)

IC801 Pin 81 FOK input check?

IC806 “FEO” output? (Pin 48)

IC827 FZC and SENS output check?

IC827 SMDP signal output? Pin 75 check?

IC808 disc MOTOR output 17, 18 check?

• Pick-up defective.

• PN802 defective.

• Turntable height error.

• Laser diode degraded.

• IC801 Pin 81 defective.

• IC806 defective.

• IC808 defective.

• IC808 Surrounding circuitry defective.

• Pin 75 pattern defective.

• X802 defective.

• IC827 defective.

• IC806 defective.

• IC806 Pin 78, 79, 80, 3, 4

defective.

• IC806 defective.

• PN801 connector defective.

• Pick-up defective.

YES

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Is leas-in?

IC827 Pin 66 EFM check?

IC806 defective.

IC801 defective.

IC801 Pin 16 SQCK check?

IC827 defective.

IC801 defective.

•

IC827 Pin 25 pattern defective.

•

IC827 defective.

IC801 Pin 14 input check?

IC827 Pin 25 “GFS” input?

IC801 Pin 88 SCOR check?

YES

2-4. Is Lead-in

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2-5. Audio signal KARAOKE AND VCD(A, B)

(A) KARAOKE AUDIO.

IC829 Pin 49 input check?

IC814 Pin 107, 108, 109 output?

IC814 defective.

IC825 Pin 14, 16 output?

RESET surrounding circuitry defective.

defective.

IC824 Pin 1 input check?

IC824 Pin 3, 6, 10 input check?

IC825 Pin 1, 2, 3 input check?

IC825 defective.

IC801 defective.

IC829 defective.

IC824 defective.

IC830 DATA LINE ADRS LINE check?

IC825 defective.

IC829 Pin 17 RESET check?

•

IC801 defective.

•

IC801 Pin 52 defective.

(B) VCD AUDIO.

OFF

VCD

KARAOKE

YES

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3. VIDEO PART

PICTURE DEFECTIVE.

IC803 Pin 8 check?

IC814 defective.

IC828 Pin 52 “RSTB” check?

IC828 “RGB” input check?

IC828 defective.

COLOR DEFECTIVE.

3-1

3-2

•

IC801 defective.

•

IC803 defective.

YES

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COLOR DEFECTIVE.

3-2

R882 defective.

IC828 defective.

R882 check?

R882

YES

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WAVEFORMS OF MAJOR CHECK POINT

1. HF signal (RF signal ) waveform (Test Point PN809) during normal play

2. EFM signal (pin31 of IC 806)waveform during Normal Play

3. Focus coil drive waveform(Pin NO 1, 2 of IC 808)

• When focus search failed or there is no disc on the tray

• Focus coil drive waveform(pin NO 1, 2 of IC808) and FOK (pin NO 40 of IC 806) when focus search is accomplished

4. Tracking coil drive waveform (pin NO 25 of IC 808) and TEO during track traverse (1) When time division is 20nS/div

(2) When time division 0.5nS/div.

(During forward track traverse)

(3) When time division is 0.5nS/div.

(During backward Track Traverse)

5. Feed motor drive waveform(pin NO 10 of IC 808) During normal play

CH1 : FOCUS COIL DRIVE

SIGNAL 2V/Div.

CH2 : FOAK

CH1 : TEO(TP801)

1V/Div.

CH2 : TRACKING COIL DRIVE

SIGNAL 2V/Div.

(

CH1 : TEO(TP801)

1V/Div.

CH2 : TRACKING COIL DRIVE

SIGNAL 2V/Div.

(

CH1 : TEO(TP801)

1V/Div.

CH2 : TRACK COIL DRIVE

SIGNAL 2V/Div.

(

0.5V/Div. 500nS/Div.

(

2V/Div. 500nS/Div.

(

0.5V/Div. 500nS/Div.

OV (CH1)

(CH2)

(CH1)

(CH2)

(CH1)

(CH2)

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LG FFH-2103 SERVICE MANUAL

Specifications and Main Features

Frequently Asked Questions

User Manual