LG FFH-M217X, FE-M217E Schematic

MP3 CD MICRO SYSTEM

SERVICE MANUAL

SERVICE MANUAL MODEL: FFH-M217X, FE-M217E

CAUTION

BEFORE SERVICING THE UNIT, READ THE “SUMMARY” IN THIS MANUAL.

MODEL: FFH-M217X, FE-M217E

- 1-1 -

[CONTENTS]

❍ SECTION 1. GENERAL

• SERVICING PRECAUTIONS

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

1-2

• ESD PRECAUTIONS

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

1-4

• SPECIFICATION

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

1-5

❍ SECTION 2. ELECTRICAL SECTION

• ADJUSTMENTS

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

2-1

• TROUBLESHOOTING ............................................................................................................... 2-2

• WAVEFORMS OF MAJOR CHECK POINT............................................................................. 2-18

• INTERNAL BLOCK DIAGRAM OF ICs .................................................................................... 2-20

• BLOCK DIAGRAM

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

2-25

• SCHEMATIC DIAGRAMS

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

2-27

• WIREING DIAGRAM ................................................................................................................ 2-29

• PRINTED CIRCUIT DIAGRAMS .............................................................................................. 2-33

❍ SECTION 3. EXPLODED VIEWS

• CABINET AND MAIN FRAME SECTION

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

3-1

• TAPE DECK MECHANISM: SINGLE AUTO REVERSE DECK

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

3-3

• OPTION PICK-UP CARRIAGE

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

3-5

❍ SECTION 4. SPEAKER PART

• SPEAKER PART

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

4-1

❍ SECTION 5. REPLACEMENT PARTS LIST

• REPLACEMENT PARTS LIST

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

5-1

❏ 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.

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Storage in conductive bag

Drop impact

NEVER look directly at the laser beam, and don’t let contact fingers or other exposed skin.

Magnet

Howtoholdthepick-up

Pressure

Cotton swab

Conductive Sheet

SECTION 1. GENERAL

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.

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Armband

Conductive Sheet

Resistor (1 Mohm)

VOLUME KNOB

DOWN

VOLUME

RESET jump wire

RESET

❐ 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]

-1-4-

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.

❏ SPECIFICATIONS

- 1-5 -

General Power supply Refer to the back panel of the unit

Power consumption 50W

Mass 4.2kg

Extemal dimensions(W X H X D)

161 X 249 X 275mm

CD Frequency Response 40 -18000Hz

Signal-to-noise ratio 70dB

Dynamic range 70dB

Tuning Range 87.5 -108.0MHz or 65 ~ 74MHz, 87.5 ~108.0 MHz

Intermediate Frequency 10.7 MHz

FM Signal-to-noise ratio 60/55 dB

Frequency Response 60 -10000Hz

Tuning Range 522-1620kHz or 520-1720kHz

AM Intermediate Frequency 450kHz

Signal-to-noise ratio 35 dB

Frequency Response 100 -1800 Hz

AMP Output Power 20W + 20W

T.H.D 0.2%

Frequency Response 40-25000Hz

Signal-to-noise ratio 80dB

TAPE Tape Speed 3000 ± 3% (MTT-111, NORMAL-SPEED)

Wow Flutter 0.25% (MTT-111,JIS-WTD)

F.F/REW Time 120sec(C-60)

Frequency Response 250-8000Hz

Signal-to-noise ratio 43dB(P/B)/43dB(R/P)

Channel Separation 50dB(P/B)/45dB(R/P)

Erase Ratio 55dB (MTT-5511)

Speaker Type 2 Way 2 Speaker

Impedance 6Ω

Frequency Response 85-20000Hz

Sound Pressure Level 88dB/W(1m)

Rated Input Power 20W

Max.Input Power 40W

Net Dimension(W

X H X D) 153 X 240 X 220mm

Net Weight(1EA) 2.24kg

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

TUNER

-1-6-

- 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

❏ 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

SECTION 2. ELECTRICAL SECTION

-2-2-

❏ TROUBLESHOOTING

• AUDIO PART

VKK PART

Does DC - 33V appear at

PN301 pin .

Check the pattern of FRONT

PCB ASS’Y

Check the DC -35V of C928(-)

Check the DC -33V of

ZD 902(-)

Check the DC -33V of

Q901 “E”

Check the PATTERN

Replace the D936

Replace the ZD902

Replace the Q901

YES

P-SENS PART

Does +5V appear at ZD901?

Check the pattern of

IC301 pin .

Check the waveform

of D937 (+).

Replace ZD901.

Replace the D937

YES

- 2-3 -

POWER CIRCUIT

Check the Fuse

Check the DC output

of C921(+)

Check the DC 12V

Output of IC901

Check the DC 6.2V

output of IC902

Check the DC 12V

Output of IC903

Check the 5.6V of Q604 “C”

(CD FUNCTION)

END

Replace the Fuse

CHECK THE AC VOLTAGE

OF CN901

1, 4

Replace the IC903

Replace the D921, D922,

D923, D924

Replace the IC902

Check DC VOLTAGE OF

D930(+)

Check the “High” of

IC903 pin4

Check the “High” of Q605“B”

Replace the Q604

Replace the IC902

Replace the Transformer

Replace the D930

Check the "High" of

PN601 pin5

Check the “High” of

IC601 pin12

YES

-2-4-

AUDIO ABNORMAL

Check the signal output of

IC701 pin2, 4

Check the signal input of IC701

pin7, 11

Check the DC +9V of IC601

pin1

Check the “High” of Q702 “B”

Check the “High” of

IC701 pin5

Check the power of IC701

Check the connecting to

SPEAKER

YES

MUTING CIRCUIT (MUTE)

Dose “High” appear at

Q701, Q751“B”

check the “Low” of Q701,

Q751, “C”

MUTE

Check the “High” of PN601 pin4

Check the “High” of

the IC301 pin12

Replace the Q703

Replace the TR

Refer to IC 301

Troubleshooting

YES

- 2-5 -

FUNCTION MODE AUDIO ABNORMAL

TAPE

Check the signal input

of IC601 pin6, 23

Refer to “IC201 Troubleshooting”

AUX

Chekc the signal input of IC601,

5, 24

Check the signal input of JK601

Check the signal input of IC601

3, 26

Check the signal input of PN603 pin6, 8

Check the signal input of IC601 pin4, 25

Refer to “TUNER PACK Troubleshooting”

TUNER

-2-6-

Refer to “IC301

Troubleshooting”

IC301 TROUBLESHOOTING

IC601 TROUBLESHOOTING

Check the power supplying IC301

31,32,51,88?

Refer to “Power Circuit Troubleshooting”

Check the P-SENS

Replace the X301

Check the RESET circuit

Refer to “Power Circuit Troubleshooting”

Check the Data of IC301 pin14, 15

(CD ➞ TAPE FUNCTION)

Replace the

IC601

Check the pattern

Check the P-SENS “High” of IC301 pin6

Check the oscillation of X301

When power supplying to IC301 pin92.

(Low ➞ High)

Replace the IC301

Check the power supplying

to IC601 pin1

Check the CLK Data of IC601 pin14, 15

Check the IC601 FUNCTION SELECTOR

END

YES

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