NAD L-56 Service manual

SERVICE MANUAL

DVD/VIDEO CD/CD

L56

PLAYER

L56

DVD/VIDEO CD/CD

PLAYER

1-2

1-3

PRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS

CAUTION : DO NOT ATTEMPT TO MODIFY THIS PRODUCT IN ANY WAY. NEVER PERFORM CUSTOMIZED INSTALLATIONS WITHOUT MANUFACTURER’S APPROVAL. UNAUTHORIZED MODIFICATIONS WILL NOT ONLY VOID THE WARRANTY, BUT MAY LEAD TO YOUR BEING LIABLE FOR ANY RESULTING PROPERTY DAMAGE OR USER INJURY.

SERVICE WORK SHOULD BE PERFORMED ONLY AFTER YOU ARE THOROUGHLY FAMILIAR WITH ALL OF THE FOLLOWING SAFETY CHECKS AND SERVICING GUIDELINES. TO DO OTHERWISE, INCREASES THE RISK OF POTENTIAL HAZARDS AND INJURY TO THE USER.

WHILE SERVICING, USE AN ISOLATION TRANSFORMER FOR PROTECTION FROM A.C. LINE SHOCK.

SAFETY CHECKS

AFTER THE ORIGINAL SERVICE PROBLEM HAS BEEN

CORRECTED. A CHECK SHOULD BE MADE OF THE

FOLLOWING.

SUBJECT : FIRE & SHOCK HAZARD

1. BE SURE THAT ALL COMPONENTS ARE POSITIONED IN SUCH A WAY AS TO AVOID POSSIBILITY OF ADJACENT COMPONENT SHORTS. THIS IS ESPECIALLY IMPORTANT ON THOSE MODULES WHICH ARE TRANSPORTED TO AND FROM THE REPAIR SHOP.

2. NEVER RELEASE A REPAIR UNLESS ALL PROTECTIVE DEVICES SUCH AS INSULATORS, BARRIERS, COVERS, SHIELDS, STRAIN RELIEFS, POWER SUPPLY CORDS, AND OTHER HARDWARE HAVE BEEN REINSTALLED PER ORIGINAL DESIGN. BE SURE THAT THE SAFETY PURPOSE OF THE POLARIZED LINE PLUG HAS NOT BEEN DEFEATED.

3. SOLDERING MUST BE INSPECTED TO DISCOVER POSSIBLE COLD SOLDER JOINTS, SOLDER SPLASHES OR SHARP SOLDER POINTS. BE CERTAIN TO REMOVE ALL LOOSE FOREIGN PARTICLES.

4. CHECK FOR PHYSICAL EVIDENCE OF DAMAGE OR DETERIORATION TO PARTS AND COMPONENTS. FOR FRAYED LEADS, DAMAGED INSULATION (INCLUDING A.C. CORD). AND REPLACE IF NECESSARY FOLLOW ORIGINAL LAYOUT, LEAD LENGTH AND DRESS.

5. NO LEAD OR COMPONENT SHOULD TOUCH A RECEIVING TUBE OR A RESISTOR RATED AT 1 WATT OR MORE. LEAD

TENSION AROUND PROTRUDING METAL SURFACES MUST

BE AVOIDED.

6. ALL CRITICAL COMPONENTS SUCH AS FUSES, FLAMEPROOF RESISTORS, CAPACITORS, ETC. MUST BE REPLACED WITH EXACT FACTORY TYPES, DO NOT USE REPLACEMENT COMPONENTS OTHER THAN THOSE SPECIFIED OR MAKE UNRECOMMENDED CIRCUIT MODIFICATIONS.

7. AFTER RE-ASSEMBLY OF THE SET ALWAYS PERFORM AN A.C.LEAKAGE TEST ON ALL EXPOSED METALLIC PARTS OF THE CABINET, (THE CHANNEL SELECTOR KNOB, ANTENNA TERMINALS. HANDLE AND SCREWS) TO BE SURE THE SET IS SAFETY TO OPERATE WITHOUT DANGER OF ELECTRICAL SHOCK. DO NOT USE A LINE ISOLATION TRANSFORMER DURING THIS TEST USE AN A.C. VOLTMETER, HAVING 5000 OHMS PER VOLT OR MORE SENSITIVITY, IN THE FOLLOWING MANNER; CONNECT A 1500 OHM 10 WATT RESISTOR, PARALLELED BY A .15 MFD,

150.V A.C TYPE CAPACITOR BETWEEN A KNOWN GOOD EARTH GROUND (WATER PIPE, CONDUIT, ETC.) AND THE EXPOSED METALLIC PARTS, ONE AT A TIME. MEASURE THE A.C. VOLTAGE ACROSS THE COMBINATION OF 1500 OHM RESISTOR AND .15 MFD CAPACITOR. REVERSE THE A.C. PLUG AND REPEAT A.C. VOLTAGE MEASUREMENTS FOR EACH EXPOSED METALLIC PART.

VOLTAGE MEASURE MUST NOT EXCEED 75 VOLTS R.M.S. THIS CORRESPONDS TO 0.5 MILLIAMP A.C ANY VALUE EXCEEDING THIS LIMIT CONSTITUTES A POTENTIAL SHOCK HAZARD AND MUST BE CORRECTED IMMEDIATELY.

SUBJECT : GRAPHIC SYMBOLS

SUBJECT : TIPS ON PROPER INSTALLATION

1. NEVER INSTALL ANY PRODUCT IN A CLOSED-IN RECESS, CUBBYHOLE OR CLOSELY FITTING SHELF SPACE. OVER OR CLOSE TO HEAT DUCT, OR IN THE PATH OF HEATED AIR FLOW.

2. AVOID CONDITIONS OF HIGH HUMIDITY SUCH AS: OUTDOOR PATIO INSTALLATIONS WHERE DEW IS A FACTOR, NEAR STEAM RADIATORS WHERE STEAM LEAKAGE IS A FACTOR, ETC.

3. AVOID PLACEMENT WHERE DRAPERIES MAY OBSTRUCT

REAR VENTING. THE CUSTOMER SHOULD ALSO AVOID THE USE OF DECORATIVE SCARVES OR OTHER COVERINGS WHICH MIGHT OBSTRUCT VENTILATION.

4. WALL AND SHELF MOUNTED INSTALLATIONS USING A COMMERCAL MOUNTING KIT MUST FOLLOW THE FACTORY APPROVED MOUNTING INSTRUCTIONS A PRODUCT MOUNTED TO A SHELF OR PLATFORM MUST RETAIN ITS ORIGINAL FEET (OR THE EQUIVALENT THICKNESS IN SPACERS) TO PROVIDE ADEQUATE AIR FLOW ACROSS THE BOTTOM, BOLTS OR SCREWS USED FOR FASTENERS MUST NOT TOUCH ANY PARTS OR WIRING. PERFORM LEAKAGE TEST ON CUSTOMIZED INSTALLATIONS.

5. CAUTION CUSTOMERS AGAINST THE MOUNTING OF A PRODUCT ON SLOPING SHELF OR A TILTED POSITION, UNLESS THE PRODUCT IS PROPERLY SECURED.

6. A PRODUCT ON A ROLL-ABOUT CART SHOULD BE STABLE ON ITS MOUNTING TO THE CART. CAUTION THE CUSTOMER ON THE HAZARDS OF TRYING TO ROLL A CART WITH SMALL CASTERS ACROSS THRESHOLDS OR DEEP PILE CARPETS.

7. CAUTION CUSTOMERS AGAINST THE USE OF A CART OR STAND WHICH HAS NOT BEEN LISTED BY UNDERWRITERS LABORATORIES, INC. FOR USE WITH THEIR SPECIFIC MODEL OF TELEVISION RECEIVER OR GENERICALLY APPROVED FOR USE WITH T.V.’S OF THE SAME OR LARGER SCREEN SIZE.

8. CAUTION CUSTOMERS AGAINST THE USE OF EXTENSION CORDS, EXPLAIN THAT A FOREST OF EXTENSIONS SPROUTING FROM A SINGLE OUTLET CAN LEAD TO DISASTROUS CONSEQUENCES TO HOME AND FAMILY.

THE LIGHTNING FLASH WITH ARROWHEAD SYMBOL, WITHIN AN EQUILATERAL TRIANGLE, IS INTENDED TO ALERT THE USER TO THE PRESENCE OF UNINSULATED “DANGEROUS VOLTAGE” WITHIN THE PRODUCT’S ENCLOSURE 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 USER TO THE PRESENCE OF IMPORTANT OPERATING AND MAINTENANCE (SERVICING) INSTRUCTIONS IN THE LITERATURE ACCOMPANYING THE APPLIANCE.

A.C. VOLTMETER

PLACE THIS PROBE ON EACH EXPOSED METAL PART

GOOD EARTH GROUND SUCH AS THE WATER PIPE. CONDUIT. ETC

10 WATT

1500 OHM

0.15uF

1-4

SERVICING PRECAUTIONS

CAUTION : Before servicing the DVD player covered by this service data and its supplements and addends, read and follow the SAFETY PRECAUTIONS. NOTE : if unforeseen circumstances create conflict between the following servicing precautions and any of the safety precautions in this publication, always follow the safety precautions.

Remember Safety First:

General Servicing Precautions

1. Always unplug the DVD player's AC power cord from the AC power source before: (1) Removing or reinstalling any component, circuit board,

module, or any other assembly.

(2) Disconnecting or reconnecting any internal electrical plug or

other electrical connection.

(3) Connecting a test substitute in parallel with an electrolytic

capacitor. Caution : A wrong part substitution or incorrect polarity installation of electrolytic capacitors may result in an explosion hazard.

2. Do not spray chemicals on or near this DVD player or any of its assemblies.

3. Unless specified otherwise in this service data, clean electrical contacts by applying an appropriate contact cleaning solution to the contacts with a pipe cleaner, cottontipped swab, or comparable soft applicator. Unless specified otherwise in this service data, lubrication of contacts is not required.

4. Do not defeat any plug/socket B+ voltage interlocks with which instruments covered by this service manual might be equipped.

5. Do not apply AC power to this DVD player and/or any of its electrical assemblies unless all solid-state device heat sinks are correctly installed.

6. Always connect test instrument ground lead to the appropriate ground before connecting the test instrument positive lead. Always remove the test instrument ground lead last.

Insulation Checking Procedure

Disconnect the attachment plug from the AC outlet and turn the power on. Connect an insulation resistance meter(500V) to the blades of the attachment plug. The insulation resistance between each blade of the attachment plug and accessible conductive parts (Note 1) should be more than 1M-ohm. Note 1 : Accessible Conductive Parts including Metal panels, Input terminals, Earphone jacks, etc.

Electrostatically Sensitive (ES) Devices

Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components commonly are called Electrostatically Sensitive (ES) Devices. Examples of typical Es 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 ES 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 ES devices.

4. Use only an antistatic solder removal device. Some solder removal devices not classified a “anti-static” can generate electrical charges sufficient to damage ES devices.

5. Do not use freonpropelled chemicals. These can generate electrical charge sufficient to damage ES devices.

6. Do not remove a replacement ES device from its protective package until immediately before you are ready to install it. (Most replacement ES devices are packaged with leads electrically shorted together by conductive foam, aluminum foil, or comparable conductive material).

7. lmmediately before removing the protective material from the leads of a replacement ES 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 handing unpackaged replacement ES devices. (Normally 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 ES device.)

1-5

DVD player/Outputs/Supplied Accessories

[DVD player]

[Outputs]

[Supplied

Accessories]

Power supply AC 230V / 50 Hz (EUROPE), AC 110V/60Hz (USA / CANADA)

Power consumption 15 W

Mass 3.3 kg

External dimensions (W X H X D) 285 x 103x 291 mm

Signal system PAL (EUR) , NTSC (USA / CANADA)

Laser Semiconductor laser, wavelength 650 nm

Frequency range (audio) 4 Hz to 20 kHz

Signal-to-noise ratio (audio) More than 100 dB (EIAJ)

Dynamic range (audio) More than 95 dB (EIAJ)

Harmonic distortion (audio) 0.008 %

Wow and flutter

Below measurable level (less than + 0.001 % (W.PEAK)) (EIAJ)

Operating conditions Temperature: 41°F to 95°F, Operation status: Horizontal

Video output 1.0 V (p-p), 75 , negative sync., RCA jack x 1

S-video output (Y) 1.0 V (p-p), 75 , negative sync., Mini DIN 4-pin x 1

SCART video output CVBS 1.0 V (p-p), 75 , negative sync., RCA jack x 1

(RGB) 0.63 V (p-p), 75

Audio output (digital audio) 0.5 V (p-p), 75 , RCA jack x 1

Audio output (optical audio) Optical connector x 1

Audio output (analog audio) 2.0 Vrms(1 KHz, 0 dB), 330 , RCA jack (L, R) x 1

Video cable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Audio cable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

* Designs and specifications are subject to change without notice.

F ront P anel

POWER indicator

(S tandby m ode : B lue colo r)

POWER button

REMOTE SENSOR

DISPLAY WINDOW

OPEN/CLOSE button

SKIP/SCAN buttons

Disc tray

PLAY button

PAUSE/STEP button

STOP button

OPERATING STATUS indicator

CD indicator

VCD indicator

DVD indicator

PROGRAM indicator

Repeat playback mode indicators

CHP/TRK NUMBER indicator

TOTAL PLAYING TIME/ELAPSED TIME indicator

TITLE NUMBER indicator

ANGLE ICON indicator

DVD / CD / MP3 Player L 56

Dis play Window

1-6

REMOTE CONTROL

1-8

1. POWER ON/OFF button (L76/L56)

2. DEVICE SELECTOR buttons

3. PROGRAM buttons (L56)

4. CLEAR button (L56)

5. REPEAT button (L56)

6. INPUT SOURCE SELECTOR buttons(L76), NUMERIC buttons (L76/L56)

7. OSD ON/OFF buttons (L76), DVD SET UP button (L56)

8. MUTE button (L76)

9. PRESET UP/DOWN buttons (L76), SLOW buttons (L56)

10. TEST TONE button (L76), ZOOM button (L56)

11. SURROUND MODE button (L76), RANDOM button (L56)

12. VOLUME UP/DOWN buttons (L76)

13. AM button (L76), TITLE button (L56)

14. FM button (L76), MENU button (L56)

15. ARROW buttons (L76/L56)

16. ENTER button (L76/L56)

17. DIGITAL INPUT/ RDS button (L76), DVD DISPLAY button (L56)

18. SLEEP button (L76), RETURN button (L56)

19. OPEN/CLOSE button (L56)

20. STOP button (L56)

21. PAUSE button (L56)

22. REV SCAN/SKIP button (L56)

23. PLAY button (L56)

24. FOR SCAN/ SKIP button (L56)

25. SURROUND LEVEL UP/DOWN buttons (L76)

26. CENTER LEVEL UP/DOWN buttons (L76)

27. SUBWOOFER LEVEL UP/DOWN buttons (L76)

DEVICE SELECTOR

AMP

TUNER

TAPE

PROGRAM

DVD

AUX

SETUP

10+

SLOW

PRESET

SLOW

TITLE

DISP

SURR.

 



DVD

CAB/SAT

VCR

CLEAR

VIDEO 1

TAPE

/ZOOM

TV/VIDEO

TEST

LEARN

RANDOM

SURR. MODE

ENTER

CHANNEL VOLUME

CENTER

HTR L76

OFF

MACRO

REPEAT

VIDEO 2

TUNER

MUTE

VOL

SLEEP

RTN

SUB

EXPLODED VIEW(L56C)

S10

S11

x11

S3 S4

S7 S8

S10

S11

DESCRIPTION

SCREW

SCREW,SPECIAL

SCREW SCREW

SCREW

PARTS-NO

CTB3+6F

CHD1A016 CTS3+8J

CTB3+6J

CTB3+10G CTW3+8J

CTW3+12J

CTB3+8J CTB3+10GFZ

CTB3+6JFZ 9

CTB4+6JFZ

QT`Y

DESCRIPTION

FRONT PANEL DOOR ORNAMENT

FIP WINDOW

SIDE BAR

LED INDICATOR

SENSOR WINDOW POWER KNOB

7 8

DISPLAY KNOB

SUB PANEL

FRONT PCB ASS'Y

SHEET

BOTTOM CHASSIS

FOOT

4 4

8 3

FOOT CUSHION

MECHA. SUPPORT

DVD PCB ASS'Y

MECHANISM,DV D

REAR PANEL

PCB HOLDER

AV PCB ASS'Y

POWER PCB ASS'Y

AC CORD BUSHING

AC CORD

TOP CABINET

PARTS-NO

KKM1A106WC37

CGR1A287M7ZK102

CGU1A244A8

KKM1A051C37

CGL1A188

CGU1A245A10

CBT1A746M7K102

CBT1A745M7K102

CGW2A298

C0P11559B KGX1A304

CUA1A224

CKL1A060

CHG1A171 CMH1A191

CIP11445HSMD

HJDRL-A70060R5

CKF4A229UK1

CHE170

COP11458I

COP11489CSMPS KHR1A028

CJA2B043Z CKC1B127S35

QT`Y

0.17

4 1

1 1

2-1

SECTION 2

ELECTRICAL

CONTENTS

ELECTRICAL TROUBLESHOOTING GUIDE......................................................................2-2

1. Power (SMPS) Circuit ..............................................................................................................2-2

............................................................................................................................2-3

3. MPEG Circuit............................................................................................................................2-6

4. Front Circuit (Digitron & Key) ...............................................................................................2-7

5. RF/Servo Circuit ......................................................................................................................2-8

BLOCK DIAGRAMS ..................................................................................................................2-12

1. Overall Block Diagram ..........................................................................................................2-12

2. Power (SMPS) Block Diagram ..............................................................................................2-13

3. RF/CD DSP/DVD DSP/DVD servo Block Diagram ..............................................................2-14

4. Audio Block Diagram ............................................................................................................2-15

5. MPEG Block Diagram...........................................................................................................2-16

...........................................................................................................2-17

CIRCUIT DIAGRAMS................................................................................................................2-18

1. Power (SMPS) Circuit Diagram ............................................................................................2-18

2. DVD DSP Circuit Diagram.....................................................................................................2-20

3. Drive & RF Circuit Diagram ..................................................................................................2-22

4. MPEG Circuit Diagram ..........................................................................................................2-24

4-1. WAVEFORMS ...................................................................................................................2-26

5. Audio DM & 5.1CH Circuit Diagram .....................................................................................2-28

....................................................................................................................2-30

7. DIGITRON & Key Circuit Diagram ........................................................................................2-32

8. Jack Circuit Diagram .............................................................................................................2-34

PRINTED CIRCUIT DIAGRAMS ............................................................................................2-36

1. MAIN P.C.BOARD ...................................................................................................................2-36

2. POWER P.C.BOARD..............................................................................................................2-38

3. AV P.C.BOARD .......................................................................................................................2-40

4. FRONT P.C.BOARD

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

2-42

2-2

ELECTRICAL TROUBLESHOOTING GUIDE

1. POWER (SMPS) Circuit

No LED

Is 5.2V applied to CN62 Pin 5 ?

Check R622, R623

Is 5.2V applied to PT61 Pin 1 ?

Check D601-D604

Check Q626, D609

YES

Check FRONT Circuit

Check L620, R620

No 8V No 3.3V

Check Q622, Q623, R632

No 5V_D, 5V_A

Is High State applied

to CN63 Pin 2 ?

YES

Check Q620, Q625, R625

Check IC67, R609

NO FLD

Is -24V applied to CN62 Pin 3 ?

YES

END

Check D625, IC62

Check IC64, D628, D621

2-3

2. u-COM Circuit A. NO Power

AC In

Is LED On?

YES

Power On Reconnect CN61

Is LED Off ?

YES

Does bar appear

on FLD ?

YES

Does logo appear on the screen?

YES

Is CN61 conneted

correctly?

Check L620, R620 Check Power Circuit

Is oscillation of X501 normal?

Are IC503 Pin 14, 28 and 29 normal?

YES

Is 5.2V applied to CN61 Pin 12 ?

YES

Check FRONT Circuit

Check the oscillation

The waveform on

A[00:21] and D[00:15] of

IC501 normal?

YES

Are IC506 Pin 7, 8 normal?

YES

Replace Main B/D

Check short

YES

Replace IC501 or IC503

2-4

B. Audio abnormal

D. Open/Close abnormal

Check the

connection of P5901.

Check IC501 Pins 13, 14.

Check Audio jack.

YES (If OK)

YES

(If OK)

YES

YES (If OK)

Check PLL FC of MPEG part.

Refer to Audio part.

Refer to MPEG part.

Replace B/D.

Check Front.

Reconnect it.

Refer to SERVO part.

Check the connection of MD.

AUDIO ABNORMAL

OPEN/CLOSE ABNORMAL

C. Video abnormal

Check Video jack.

YES (If OK)

Refer to Video part.

Refer to Encoder part.

Refer to MPEG part.

Replace B/D.

VIDEO ABNORMAL

2-5

E. Picture abnormal

Check the disc.

If OK

YES (If OK)

Refer to Servo part

Check PLL IC of MPEG part

Check DSP

Check MPEG

YES (If OK)

Replace B/D

PICTURE ABNORMAL

F. Disc Error

Check Disc

YES (If OK)

Refer to Servo part

Replace B/D

DISC ERROR

2-6

Power is on

Does LG Logo appear

on the screen?

Does the

moving picture of the DVD Disc

play on the screen

normally?

Is MPEG data signal normal?

Is error signal normal?

Is MPEG data signal normal?

Is Clock normal?

Does the audio

sound output from MPEG

decoder?

Does the

moving picture of the video

CD play on the screen

normally?

Does the audio sound

output normally?

END

Check power & clock.

Check CD/DVD DSP output

signal.

Check MPEG Decoder input

signal.

Check CD/DVD DSP output

signal.

Check MPEG Decoder input

signal.

Check CD/DVD DSP output

signal.

Check MPEG Decoder input

signal.

Check clock signal

YES

3. MPEG Circuit

OPTION

If included VCD function.

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