SAMSUNG MAX455KSC Service Manual

3CD CHANGER MINI COMPONENT

1. Precautions

2. Specifications

3. Disassembly and Reassembly

4. Alignment and Adjustments

5. Special Circuit Descriptions

6. Troubleshooting

7. Exploded Views and Parts List

8. Electrical Parts List

9. Block Diagrams

10. PCB Diagrams

11. Wiring Diagram

12. Schematic Diagrams

SERVICE

Manual

3 CD CHANGER MINI COMPONENT SYSTEM

MAX-445/455

CONTENTS

Samsung Electronics Co., Ltd. Dec. 1996. Code No. AH68-20144A

1. Precautions

Follow these safety, servicing and ESD precautions to prevent damage and protect against potential hazards such as electrical shock and X-rays.

1-1 Safety Precautions

1. Be sure that all of the built-in protective devices are replaced.

(Reading should

2. When reinstalling the chassis and its assemblies, be sure to restore all protective devices, including control knobs and compartment covers.

3. Make sure that there are no cabinet openings through which people-particularly children--might insert fingers and contact dangerous voltages. Such openings include the spacing between the picture tube and the cabinet mask, excessively wide cabinet ventilation slots, and improperly fitted back covers.

Device Under

Test

Test all

exposed metal

surfaces

2-Wire Cord

Also test with plug reversed (using AC adapter plug as required)

Fig. 1-1 AC Leakage Test

not be above

0.5mA)

Leakage Currant Tester

Earth Ground

4. Design Alteration Warning: Never alter or add to the mechanical or electrical design of the unit. Example: Do not add auxiliary audio or video connectors. Such alterations might create a safety hazard. Also, any design changes or additions will void the manufacturer's warranty.

5. Leakage Current Hot Check (Figure 1-1): Warning: Do not use an isolation transformer during this test. Use a leakagecurrent tester or a metering system that complies with American National Standards Institute (ANSI C101.1, Leakage Current for Appliances), and Underwriters Laboratories (UL Publication UL1410, 59.7).

With the unit completely reassembled, plug the AC line cord directly into a 120V AC outlet. With the unit's AC switch first in the ON position and then OFF, measure the current between a known earth ground (metal water pipe, etc.) and all exposed metal parts. Examples: Handle brackets, metal cabinets, screwheads and control shafts. The current measured should not exceed 0.5 milliamp. Reverse the powerplug prongs in the AC outlet and repeat.

6. Insulation Resistance Cold Check: (1) With the unit's AC plug disconnected from the AC source, connect an electrical jumper across the two AC prongs. (2) Set the power switch to ON. (3) Measure the resistance between the shorted AC plug and any exposed metallic parts. Example: Screwheads, antenna, control shafts or handle brackets.

If any of the exposed metallic parts has a return path to the chassis, the measured resistance should be between 1 and 5.2 megohms. If there is no return path, the measured resistance should be "infinite." If the resistance is outside these limits, a shock hazard might exist. See Figure 1-2

Antenna Terminal

Exposed Metal Part

ohm

Ohmmeter

Fig. 1-2 Insulation Resistance Test

Samsung Electronics 1-1

Precautions

1-1 Safety Precautions (Continued)

7. Components, parts and wiring that appear to have overheated or that are otherwise

damaged should be replaced with parts that meet the original specifications. Always determine the cause of damage or overheating, and correct any potential hazards

8. Observe the original lead dress, especially

near the following areas: Antenna wiring, sharp edges, and especially the AC and high voltage power supplies. Always inspect for pinched, out-of-place, or frayed wiring. Do not change the spacing between components and the printed circuit board. Check the AC power cord for damage. Make sure that no wires or components touch thermally hot parts.

1-2 Servicing Precautions

9. Product Safety Notice: Some electrical and mechanical parts

have special safety-related characteristics which might not be obvious from visual inspection. These safety features and the protection they give might be lost if the replacement component differs from the original--even if the replacement is rated for higher voltage, wattage, etc.

10 Components that are critical for safety are

indicated in the circuit diagram by

shading, or . Use replacement

components that have the same ratings,

especially for flame resistance and

dielectric strength specifications. A

replacement part that does not have the

same safety characteristics as the original

might create shock, fire or other hazards.

Warning1: First read the "Safety Precautions" section of this manual. If some unforeseen circumstance creates a conflict

between the servicing and safety precautions, always follow the safety precautions.

1. Servicing precautions are printed on the cabinet. Follow them.

2. Always unplug the unit's AC power cord from the AC power source before attempting to: (a) Remove or reinstall any component or assembly, (b) Disconnect an electrical plug or connector, (c) Connect a test component in parallel with an electrolytic capacitor.

3. Some components are raised above the printed circuit board for safety. An insulation tube or tape is sometimes used. The internal wiring may be clamped to prevent contact with thermally hot components. Reinstall all such elements to their original position.

4. After servicing, always check that the screws, components and wiring have been correctly reinstalled. Make sure that the portion around the serviced part has not been damaged.

5. Check the insulation between the blades of the AC plug and accessible conductive parts (examples: metal panels, input terminals and earphone jacks).

6. Insulation Checking Procedure: Disconnect the power cord from the AC source and turn the power switch ON. Connect an insulation resistance meter (500V) to the blades of the AC plug.

The insulation resistance between each blade of the AC plug and accessible conductive parts (see above) should be greater than 1 megohm.

7. Never defeat any of the B+ voltage interlocks. Do not apply AC power to the unit (or any of its assemblies) unless all solid-state heat sinks are correctly installed.

8. Always connect a test instrument's ground lead to the instrument chassis ground before connecting the positive lead; always remove the instrument's ground lead last.

Samsung Electronics1-2

1-3 Precautions for Electrostatically Sensitive Devices (ESDs)

Precautions

1. Some semiconductor ("solid state") devices are easily damaged by static electricity. Such components are called Electrostatically Sensitive Devices (ESDs). Examples include integrated circuits and some field-effect transistors. The following techniques will reduce the occurrence of component damage caused by static electricity.

2. Immediately before handling any semiconductor components or assemblies, drain the electrostatic charge from your body by touching a known earth ground. Alternatively, wear a discharging wrist-strap device. (Be sure to remove it prior to applying power--this is an electric shock precaution.)

3. After removing an ESD-equipped assembly, place it on a conductive surface such as aluminum foil to prevent accumulation of electrostatic charge.

4. Do not use freon-propelled chemicals. These can generate electrical charges that damage ESDs.

5. Use only a grounded-tip soldering iron when soldering or unsoldering ESDs.

6. Use only an anti-static solder removal device. Many solder removal devices are not rated as "anti-static" (these can accumulate sufficient electrical charge to damage ESDs).

7. Do not remove a replacement ESD from its protective package until you are ready to install it. Most replacement ESDs are packaged with leads that are electrically shorted together by conductive foam, aluminum foil or other conductive materials.

8. Immediately before removing the protective material from the leads of a replacement ESD, touch the protective material to the chassis or circuit assembly into which the device will be installed.

9. Minimize body motions when handing unpackaged replacement ESDs. Motions such as brushing clothes together, or lifting a foot from a carpeted floor can generate enough static electricity to damage an ESD.

1-4 Special Precautions and Warning Labels for Laser Products

(UL)

This Product Complies with DHHS Rules 21CFR, Sub chapter J.At date of Manufacture

(SCAN)

CAUTION : INVISIBLE LASER RADIATION WHEN OPEN

AND INTERLOCKS DEFEATEO AVOIDEXPOSURE TO BEAM

ADVARSEL:USYNLIG LASERSTRÅLING VED ABNING

NÅR SIKKERHEDSAFBRYDERE ER UDE AF FUNKTION

UNDGA UDSAETTELSE FOR STRALING

VARO:AVATTAESSA JA SUOJALUKITUS OHITETTAESSA

OLET ALTTINA NAKYMATTÖMALLE LASERSATEILYLLE ALA KATSO SATEESEEN!

VARNING:OSYNLIG LASERSTRÅLNING NAR DENNA DEL

AR OPPNAD OCH SPARREN AR URKOPPLAD BETRAKTA EJSTRÅLEN!

CERTIFIED ONLY TO CANADIAN ELECTRICAL CODE.

CERTIFIE EN VERTU DU CODE CANADIAN DE LELETRICITE SEULEMENT

Fig. 1-3 Warning Labels (Location: Enclosure Block)

(EU)

(CSA)

UL : Manufactured for U.S.A. Market. CSA : Manufactured for Canadian Market. EU : Manufactured for European Market. SCAN : Manufactured for Scandinavian

Market.

(EU)

CLASS 1 LASER PRODUCT

Fig. 1-4 Warning Labels (Location: Disc Clamper, Inner Side of Unit Door or Nearby Unit Chassis )

Samsung Electronics 1-3

Precautions

1-4 Special Precautions and Warning Labels for Laser Products (Continued)

1-4-1 Warnings

1. When servicing, do not approach the LASER exit with the eye too closely. In case it is necessary to confirm LASER beam emission, be sure to observe from a distance of more than 30 cm from the surface of the objective lens on the optical pick-up block.

2. Do not attempt to handle the objective lens when the DISC is not on the tray.

1-4-2 Laser Diode Specifications

Material: GaAs+ GaAlAs Wavelength: 760-800 nm Emission Duration: Continuous

Laser Output: 0.2 mw (measured at a

1.6 mm distance from the objective lens surface on the optical pick-up block.)

1-4-3 Handling the Optical Pick-up

1. Static electricity from clothing or the body may cause electrostatic breakdown of the laser diode in the Optical Pickup. Follow this procedure:

2. Place a conductive sheet on the work bench (i.e., the black sheet used for wrapping

repair parts.) Note: The surface of the work

bench should be covered by a copper

ground plane, which is grounded.

3. The repair technician must wear a wrist strap which is grounded to the copper sheet.

4. To remove the Optical Pickup block: Place the set on the conductive sheet, and momentarily touch the conductive sheet

with both hands. (While working, do not

allow any electrostatic sources--such as clothes--to touch the unit.)

5. Ground the "Short Terminal" (located on the PCB, inside the Pickup Assembly) before replacing the Pickup. This terminal should be shorted whenever the Pickup Assembly

is lifted or moved.

short terminal

SOH91VI(LDP)

short terminal

SOH91CI(CAR,walkman)

6. After replacing the Pickup, reopen the Short Terminal. See diagrams below:

THE UNIT

(1) WRIST-STRAP FOR GROUNDING

short terminal

SOH-A1

(CMS-V10,CMS-V30)

SOH94T4N

(CMS-V10,CMS-V30)

CONDUCTIVE SHEET

short terminal

Samsung Electronics1-4

2. Specifications

Power source Power consumption (Option) Dimensions (mm)

230V 50Hz(Option) 90W (MAX-445) 150W (MAX-455) 270(W) x 315(H) x 335(D)

Power output (Option)

Total harmonic distortion Frequency range Signal to noise ratio Channel separation Input sensitivity

Frequency range Usable sensitivity Signal to noise ratio IF rejection ratio Total harmonic distoration Separation (Stereo)

Frequency range Usable sensitivity Signal to noise ratio IF rejection ratio Total harmonic distortion

Frequency range Usable sensitivity Signal to noise ratio

Frequecny range WOW FLUTTER Erasing effect Signal to noise ratio Total harmonic distortion

Frequency response Signal to noise ratio Channel separation Total harmonic distortion

87.5 ~ 108MHz 8µV 55dB 60dB

0.7% 23dB

522 ~ 1611KHz 600µV 40dB 45dB 2%

146 ~ 290KHz 1250µV 35dB

125Hz ~ 8KHz

0.35% 55dB 45dB 2%

20Hz ~ 20KHz(¡ 1dB) 90dB(1kHz 0dB) 75dB(1kHz 0dB)

0.08%(1kHz 0dB)

20W/CH(6Ω) (MAX-445) 40W/CH(6Ω) (MAX-455)

0.5% 20Hz ~ 20kHz 75dB 50dB 400mV

General

Amplifier

Tuner

Cassette

Compact Disc

(AM)

Samsung Electronics 2-1

* Specifications are subject to change without notice.

(OPTION)

3. Disassembly and Reassembly

3-1 Cabinet-Top

1. Remove 11 screws holding the cabinet-top.

2. Lift the back of the cabinet-top and slide it to the rear to remove. (See arrow)

OPTION

Samsung Electronics

3-1

Figure 3-1

3-2 CD-MECHA, DOOR-CD

1. If power is connected :

- Turn power on

- Open the tray using the open/close key

- Remove the Door in the direction of arrow #.

2. If power is not connected :

- Turn the gear clockwise using a screw driver as shown in Figure 3-2- 1.

- Pull the Tray in the direction of arrow @ and then remove the Door in the direction of arrow # .

3. Remove 2 screws $ and lift the CD-MECHA.

4 4

OPTION

3-2

Samsung Electronics

Figure 3-2-1

Figure 3-2

Disassembly and Reassembly

3-3 Cabinet-Rear and Main PCB

3-4 Cabinet-Front and Cabinet-Bottom

1. Remove 14 screws % and then lift the cabinet-rear ^ and slide it to rear to remove (see arrow).

2. Remove the Main-PCB & to rear.

A A

8 8

OPTION

1. Remove 5 screws *.

2. Remove the cabinet-rear by pushing the "A" and "B" as shown.

Samsung Electronics 3-3

Figure 3-3

Figure 3-4

7 7

OPTION

Disassembly and Reassembly

3-5 CD Mecha Main

3-4 Samsung Electronics

Disassembly and Reassembly

1313

1010

1717

1616

1212

1111

2020

1515

2121

1414

1919

CD SUB PCB

TRAY DISC ASS'Y

TRAY STOPPER

CD MAIN PCB

HOOK

BASE MAIN

1818

Refer to the next page for timming point

Figure 3-5

Samsung Electronics 3-5

Disassembly and Reassembly

3-5 CD Mecha Continued

3-5-1 Tray Disassembly

3-5-2 Main Disassembly

3-5-3 CD Main PCB Disassembly

1. Remove the Tray-Roulette (3) from the Tray-Disc AssÕy (4) by releasing the hook.

2. Remove the PCB-Sensor AssÕy (5) from the tray by releasing the hook.

3. Remove the Worm-Motor AssÕy ()) from the Tray-Disc AssÕy (4).

4. Remove the Cushion-Motor (1) from the Tray.

5. Remove the Gear-Roulette (2) from the Tray-Disc AssÕy (4) by releasing the hook.

* When removing, take extreme care not to damage the hook.

1. Open the Tray Disc AssÕy by turning the Gear-Load (%) in the direction of open, then remove the Wire-Tray (Q) .

2. Remove two Tray-Stopper and tray.

1. Remove the Table-Chuck AssÕy (6) from the Base-Main by turning it.

2. Push the Slider-Cam (!) towards right, then lift it up to remove.

3. Remove the Gear-Tray (^) from the Base-Main by releasing the fixed hook.

4. Remove the Gear-Converter (&) from the Base-Main by releasing the fixed hook.

5. Remove the Gear-Cam (%) from the Base-Main by releasing the fixed hook.

6. Remove the Belt (@) from the Pulley-Motor AssÕy (7) & the Gear-Pulley (#).

7. Remove the Gear-Pulley (#) from the Base-Main by releasing the fixed hook.

8. Remove the Gear-Load ($).

9. Remove the Gear-Synchro (*).

10. Desolder two soldering points of the CD SUB PCB, then remove it from the Base-Main by releasing

the hook.

11. Remove the Pully-Motor AssÕy (7) by releasing the hook.

12. Remove the PCB-SW AssÕy (8) by releasing the hook.

1. Remove the Lever-Lifter (9) from the Base-Main by releasing two hooks.

2. Remove four Rubber-CD (0) from the Lever-Lifter and then remove the Deck-CD (“).

3. Remove the Hook .

4. Remove the CD Main PCB with the soldering iron.

3-6

Samsung Electronics

Disassembly and Reassembly

Figure 3-6

Gear-Cam

Gear-Cover

Gear-Cam

Gear-Synchro

Gear-Disc

Insert

Gear-Tray

* Reinstall in reverse order.

* Align the Gear-cam with the gear-Tray as

shown in Figure3-6, then mount the Tray-Disc.

* When assembling the Tray-Disc, take extreme

care not to engage with Gear-Synchro.

Gear-Cam Timming Point

Figure 3-7

3-8 CD Deck

1. Remove the Shaft ! .

2. Lift the P/U @ .

Note : Take extreme care not to touch the surface of lens.

3. Lift the Center-ring # .

4. Remove the Spring-T/Table $ .

5. Remove the Turn-Table (M) % .

6. Remove 2 screw ^ and then remove the Spindle-Motor & .

7. Remove the Cover-Gear * by pushing the hook.

8. Remove the Gear(c) ( by pushing the hook.

9. Lift the Gear(b) ) .

10. Remove the Gear(a) 1 .

11. Remove 2 screws 2 and then remove the Feed-Motor 3 .

12. Remove the Chassis-Deck(M) 4.

Samsung Electronics 3-7

Figure 3-8

Disassembly and Reassembly

4. Alignment and Adjustments

4-1 Tuner

FM T.H.D Adjustment

SSG FREQ. 98MHz Adjustment

point FM DETECTOR COIL

(IFT2)

Minumum Distortion(Figure 4-1)

FM Search Level Adjustment

SSG FREQ. 98MHz Adjustment

point SEMI-VR(5KB)

(IVR1)

"TUNED" is shown on FLT(Figure 4-2)

FM Antenna Terminal

Speaker Terminal

Input

Figure 4-1 IF CENTER and T.H.D Adjustment

Figure 4-2 FM Auto Search Level Adjustment

Output

Distortion Meter

Oscilloscope

FM SSG

GND

26dB

75Ω Dummy

FM IN

FM Antenna

SET

5 kΩ

SET

Output GND

AM(MW) I.F Adjustment

SSG FREQ. 450KHz Adjustment

point AM I.F COIL

(IFT1)

Maximum output(Figure 4-3)

Figure 4-3 AM I.F Adjustment

AM ANT

60cm

IFT1

AM SSG 450KHZ

Speaker Terminal

INPUT

OUTPUT

VTVM

4-1Samsung Electronics

SPEAKER JACK

ANT JACK

Figure 4-4

Figure 4-6

4-2 Cassette Deck

4-2-1 Test Equipment

1. Oscilloscope

2. VTVM

4-2-1(a) TAPE

1. MTT-111 (or equivalent) : Test tape on which 3KHz signal is recorded (Tape speed adjustmant)

2. MTT-5512 (or equivalent)

3. MTT-113CN (or equivalent) : Test tape on which 8KHz signal is recorded (Azimuth)

4. MTT-112B (or equivalent) : Test tape on which 1KHz signal is recorded (L.R. channel unbalance)

AZIMUTH Adjustment Screw

REC PB Head

INSET

Frequency Counter

Speaker Terminal

SET

(GND)

VTVM

V H

Figure 4-5

Oscilloscope

OUT

OUTPUT

Item

Connection

Preparation

Tape speed (normal speed) adjustment

Figure 4-4

3 KHz

5200Hz ~ 6600Hz

CVR1

JPT1

Tape speed (high speed)

1) Insert MTT-111 to Deck 2.

2)Press PLAY button.

1) Insert MTT-111 to Deck 2.

2) Insert MTT-5512 to Deck1.

3) Press Hi-SPEED button.

4) Press RECORD button.

Remark

Adjustment Point

Samsung Electronics4-2

4-2-2 Location of Adjustment Points (Refer to page 4-1)

4-2-3 Adjustment Procedure

4-2-3(a) TAPE SPEED

4-2-3(b) AZIMUTH

1. DECK 1

2. DECK 2

Maximum output and identical phase of L,R channel. Set the screw after adjustment.

Item

Connection

Preparation

AZIMUTH

Figure 4-5

L-CH R-CH

0.5dB

Figure 4-6

JSVR15L

L,R unbalance

Play MTT113N in the DECK1.

Play MTT112B in the DECK1.

Remark

Adjustment Point

Item

Connection

Preparation

AZIMUTH

Figure 4-5

Figure 4-6

Play MTT113N in the DECK2.

Remark

Adjustment Point

3. Recording Frequency

85KHz

Item

Connection

Preparation

Bias oscillation frequency

LL1

Record MTT5512 in the DECK1.

Remark

Adjustment Point

Alignment and Adjustments

4-3Samsung Electronics

4-3 CD

TP2

TP1

Vref

NVR1704

NVR1703 NVR1702

NVR1701

TE CENTER

FE CENTER

E.F BAL

F.BIAS

---100mV

---0V

---250mV

---0 V

---100mV

---0 V

4-3-1 To Adjust FOCUS BIAS(STOP mode)

4-3-3 To Adjust Focus Gain (PLAY mode)

4-3-2 To Adjust Tracking Gain (PLAY mode)

1. Set Volt/Div of the oscilloscope to DC 100mV.

2. Ground the scope input and set the waveform to 0V, DC range.

3. Connect the GND terminal of the oscilloscope to Vref, and (+) terminal to center of TP1.

4. Set NVR1701 to 0mV.

1. Connect the GND terminal of the oscilloscope to Vref and (+) terminal to TP2.

2. Load and play the disc

3. While the disc is running adjust the gain with NVR1704 as shown below.

1. Connect the GND terminal of the oscilloscope to Vref and (+) terminal to TP1.

2. Load and play the disc

3. While the disc is running adjust the gain with NVR1703 as shown in the following figure.

VOLT/DIV : 0.2V TIME/DIV : 2mS

Normal frequency

Low frequency

High frequency

Low frequency

High frequency

VOLT/DIV : 0.1V TIME/DIV : 2mS

VOLT/DIV : 0.2V TIME/DIV : 2mS

A=B

4-3-4 To Adjust E/F Balance (PLAY mode)

1. Set TIME/DIV of the oscilloscope to 2mS.

2. Set Volt/DIV of the oscilloscope to 0.5V.

3. Ground the scope input and set to DC and then set the DC range.

4. Connect the GND terminal of the oscilloscope to Vref and (+) terminal to center to TP2.

5. Load and play the disc.

6. Turn NVR1704 counterclockwise to the minimum value.

7. Raise NVR1702 and adjust the waveform so that its middle comes to GND of the oscilloscope (or until the upper half of waveform becomes symmetrical to the bottom half, A=B)

8. Adjust NVR1704 (arrow) for normal sound.

Alignment and Adjustments

RF I-V Amp(1) and RF I-V Amp(2) currents are converted to voltage via internal resistance of 58k½ from the current of PD1(A+C) and PD2(B+D): These voltage are added by the RF summing amplifier. The signal (A+B+C+D) is applied to RFO (No. 2 terminal). RF output voltage is calculated as follows :

VFE = (R2/R1) x (V2-V1) = 5.4(V2-V1)

This FOCUS ERROR voltage is sent to FOCUS SERVO .

VRF = -R3 x (iPD1 + iPD2)

VRF = -R3 x (V1/R1 + V2/R2)

VRF = -R3 x ( + )

VRF = - x (V1 + V2)

10K 10K

V 1 V 2

10K

Photo Detector

PD1 PD2

58K

RF I-V AMP(1)

58K

10K R2

RF I-V AMP(2)

10K

RF SUMMING

V1 AMP

RFO

5-1-1 RF Amp (KA9220) : NIC9220

5-1-2 FOCUS ERROR Amp(KA9220) : NIC9220

174K

C1 25P

FOCUS ERROR

AMP

164K

FE Bias

GNDVcc

20K

32K

C2 25P

-(A+C)

-(B+D)

V1 32K

5-1-3 FOCUS SERVO SYSTEM (KA9220) : NIC9220

When FS3 is ON, high frequency gain decreases (time constant set by pin17, pin19 ; capacitor is connected to internal resistance). The capacitor between pin 18 and GND sets the time constant to pass the low frequencies in PLAY mode.

The maximum frequency of the focus phase compensation is inversely proportional to the resistance connected to pin 7. Focus search peak is about 1.1 Vp-p, and is inversely proportional to the resistance connected to pins 22,23 (if this resistance changes, the peak of track jump and sled kick change). The inverted input of FZC comparator is set to 5.7% of the difference between Vcc and VC(pin69) {{5.7% x (Vcc-Vc)}. Note : If the resistance connected to pin7 changes, the phase compensation peak of the focus tracking sled servos change. (The 'op-amp' dynamic range and offset voltage also change.)

3.6K

60K

FZC

0.0022

20K

0.1UF

FDFCT

HFGD

EFR

FE2

470K

DFCT

FS4

20K 48K

58 60

46K

580K FS3

FSW

470K

130K

0.1UF

40K

PFSET

FS2

PHASE COMPENSATION

92K

40K

10K

4.7UF

FSCH

FS1

50K

5.5U 11U

VREG

180K

ISET

FCE

120K

FOCUS COIL

FSEO

FE1

Samsung Electronics

5-1

5-1 CD

FOCUS ERROR Amp amplifies the difference between RF I-V Amp(1) output (A+C) and RF I-V Amp(2) output(B+D). These two signals are supplied to (-) and (+) input terminals of FOCUS ERROR Amp. The FOCUS ERROR output is applied to FE (Terminal No.57). The FE output voltage of this low frequency component varies according to {(A+C) - (B+D)}. VFE is calculated as follows :

5. Special Circuit Descriptions

5-1-4 TRACKING SLED SERVO SYSTEM (KA9220) : NIC9220

The capacitor between pin 15 and 16 attenuates high frequencies when TG2 is off. The maximum frequency of tracking phase compensation is inversely proportional to the resistance connected to pin 7 (about 1.2kHz at 470k). The tracking jump (FWD and REV) is determined when TM3 and TM4 are ON, and the peak voltage induced from the tracking coil is determined by both TM3 and TM4 currents and the feed back resistance of pin 47. Track jump max voltage = TM3 (TM4) current x feedback resistance.

FWD or REV sled kick occurs when TM5 or TM6 is ON, and the peak voltage added to sled motor (determined by TM5 or TM6 current and the feedback resistance of pin 41.) Sled jump max. voltage = TM5(TM6) current x feedback resistance Each SW current is determined by the resistance connected to pin 22 and 23.

When the resistance is about 150½,

TM3 or TM4 = 11µA, TM5 or TM6 = 22µA,

This current is inversely proportional to the resistor, variable within a range of t 5 to 40 µA for TM3. STOP is the ON/OFF detection signal for the limit SW (or the sled motor's innermost cirumference).

22 23

40 41 39

47 48

0.022UF

TZC

0.047UF

150K

BPF

1K 1K

TZC

100K

ATC

20K

TE 1

TE2

470K

100K

ATS

TDFC1

0.1UF

680K

66PF

10K

DFCT

0.1UF

RTG

20K

TGSW

470K

TG2

82K

110K

PHASE

COMPENSATION

S STOP

100K

S STOP

SLED

SLEI

SLEN

10K

56K

100K

ISET VREG

180K

SLED DRIVER

120K

100K

TKEO

TKEI

TM2

TM6

TM5

TM4

5.5U

TM3

5.5U

10K

90K

TM7

PFSET

470K

TRACKING COIL

5-2 Samsung Electronics

Special Circuit Descriptions

Samsung Electronics 6-1

6. Troubleshooting

6-1 Amplifier

6-1-1 Power Malfunction

Front PCB µ-com VDD(5V)

normal?

UIC1 pin no. 18,47,90

Replace RIC1

Main PCB RIC1(BA3950) IN: 23V

Input voltage normal?

Yes

Check the Power PCB; RD7,8,13(1N5392)

Yes

Front PCB

Does UX1(12MHz)

oscillate ?

FRONT PCB PWR-SENS

voltage normal ?

(pin no. 27 ; 5V)

Check the Main PCB RD16,RR10,11,12,RC12 RD9

Yes

Front PCB

When the power is

ON 'H' displays

at pin no. 5 ?(5V)

Yes

Connect Front PCB and Main PCB.

Check the connector Main PCB.

Wafer MCW2

Replace µ-com.

Yes

Check the Power PCB : P/T, FUSE

6-2 Samsung Electronics

Yes

AQ103L,R Base B+ ?

Is Mute selected ?

Headphone Jack short ?

Remove it with Remocon.

Replace Headphone jack soldering condition.

Main PCB AIC101

(STK4121,4141,4181-Option)

pin no. 9,11,12,14

B+,B- circuits

Check the B+ power source part in RD1(PBL403), RC2,3 and RIC1.

Yes

Confirm for TR short replace it.

Check if the output line is short.

Yes

Troubleshooting

6-1-2 No Output

Samsung Electronics 6-3

IZD1(8.2V) Voltage ok ?

Yes

Check TUNER IC(LA1836)

pin no.10 ; 8.2V pin no.14 ; 7.2V

AM ; 0V ?

Yes

LC72131

CONTROL ok?

Yes

FM VT

LC72131 pin no.20

1.7V 7.5V ?

Yes

AM VT

LC72131 pin 20

Check the LC72131

CONTROL ok?

Yes

Check HIC1

pin 20 ?

LPF1,2

output ok?

Check TDA7318 function ok?

Check FEP interior

pattern, and any line

disconnections.

 1) Power impaired

so repair defects.

2) LC72131 Oscillator (HX1 : 7.2MHz) ok ?

3) System line ok?

Yes

Check for µ-com IC

Replace LC72131

HZD1 (5.6V) Voltage ok?

HIC1 (LC72131) FM/AM BAND

Switching ok?

0.9V 7V

Power section defective

RIC1(BA3950) Voltage ok?

PIN NO.8 : 12V

Check the voltage ok ?

Troubleshooting

6-1-3 Tuner Malfunction (FM/AM)

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