LG Multiplex Triple Combi TV Schematic

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REC/ITR

DVD TRK COPY VCR

REC PM TV

Triple Combi TV

SERVICE MANUAL

CAUTION

BEFORE SERVICING THE CHASSIS, READ THE SAFETY PRECAUTIONS IN THIS MANUAL.

CHASSIS : MV-033A

MODEL : Multiplex 72

website:http://biz.LGservice.com

e-mail:http://www.LGEservice.com/techsup.html

SERVICE MANUAL MODEL : Multiplex 72

LG Electronics inc.

CHASSIS : MV-033A

MODEL : Multiplex 72

CONTENT

SAFETY INSTRUCTIONS ............................ 1-2

SERVICING PRECAUTIONS ....................... 1-4

SPECIFICATION ................................................1-5

DESCRIPTION OF CONTROLS .................. 1-8

SECTION 1 SUMMARY

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OPEN/ CLOSE

STOP/ EJECT

PLAY

REC/ITR

DVD TRK COPY VCR

REC PM TV

Triple Combi TV SERVICE MANUAL

1-8

DESCRIPTION OF CONTROLS

TVCR DVDRESET EJECT

PSM

SSM

TV/AV

MUTE

VOL VOL

TEXT

1 2 3

4 5 6

7 8 9 0

C o m m u n i c a t o r

SP/LP

CLR/RST

TIMER PROG

CLK/COUNT

SYSTEMARCI/II

SLEEP

RECSTOP SKIPSKIP

PAUSEFFREW

PLAY

RETURN

TITLE

SETUP

DISC MENU

ZOOMPROGRAM

SUBTITLE

ANGLE 3D

AUDIO

REPEATMA-B

Q.VIEW LIST

POWER

8 9

All the functions can be controlled with the Communicator. Some functions can also be adjusted with the buttons on the front panel of the set.

Communicator

Before you use it, please select TV, VCR or DVD function by pressing the TVCR or DVD buttons.

1. I/II

selects the language during dual language broadcast. selects the sound output (option).

2. SLEEP

sets the sleep timer.

3. VCR BUTTONS

controls a LG video cassette recorder. For further details, see the ‘VCR Operation’ section.

4. DVD BUTTONS

controls a LG DVD player. For further details, see the ‘DVD Operation’ section.

5. RESET

When Communicator does not work, reset the Communicator by pressing the reset point with sharp one.

6. POWER

switches the set on from standby or off to standby.

7. NUMBER BUTTONS

switches the set on from standby or directly select a number.

8. MENU

selects a menu.

D / E

(Programme Up/Down)

selects a programme or a menu item. switches the set on from standby.

F / G

(Volume Down/Up)

adjusts the volume. adjusts menu settings.

accepts your selection or displays the current mode.

10. MUTE

switches the sound on or off.

11. ARC (Aspect Ratio Control)

changes the picture format.

12. TVCR / DVD

selects to control a LG video cassette recorder or DVD player.

13. EJECT

Open or close the disc tray. ejects the tape.

14. PSM (Picture Status Memory)

recalls your preferred picture setting.

15. SSM (Sound Status Memory)

recalls your preferred sound setting.

12 13

14 15

17 18

1-9

16. TV/AV

selects the remote operating mode. clears the menu from the screen. switches the set on from standby.

17. TELETEXT BUTTONS (option)

These buttons are used for teletext. For further details, see the ‘Teletext’ section.

18. LIST

displays the programme table.

19. Q.VIEW

returns to the previously viewed programme. selects a favourite programme.

COLOURED BUTTONS : These buttons are used for teletext (only TELETEXT models) or programme edit.

Internal generator charge

The communicator can be charged with the internal electric generator. To charge the communicator do the followings;

1. In first use, 20 rotation of the handle in the arrow direction as picture below

-> waiting for one minute -> 20 rotation again -> waiting for one minute again -> 20 rotation again -> beginning to use

2. In usual use 20 or 25 rotation -> resuming to use

Note : Do not rotate the handle too rapidly for the protection of the communicator.

8 9

12 13

14 15

17 18

C o m m u n i c a t o r

CLR/RST

TITLE

ANGLE 3D

Q.VIEW LIST

SYSTEMARCI/II

SP/LP

PAUSEFFREW

RECSTOP SKIPSKIP

RETURN

ZOOMPROGRAM

PSM

SSM

TV/AV

TEXT

SLEEP

TIMER PROG

CLK/COUNT

PLAY

SETUP

DISC MENU

SUBTITLE

AUDIO

REPEATMA-B

TVCR DVDRESET EJECT

POWER

1 2 3

4 5 6

7 8 9 0

VOL VOL

MUTE

Front panel

Multiplex 72 series

Multiplex 55 series

Side panel

Shown is a simplified representation of front or side panel. Here shown may be somewhat different from your set.

ON/OFF

STOP PLAY

OPEN/ CLOSE

STOP/ EJECT

PLAY

REC/ITR

ON/OFF

STOP PLAY

OPEN/ CLOSE

STOP/ EJECT

PLAY

REC/ITR

DVD TRK COPY VCR

REC

PM TV

DVD TRKCOPY VCR

REC PM TV

AV2

1 2 3 4 5 7 8 12119

310

ON/OFF

STOP PLAY

OPEN/ CLOSE

STOP/ EJECT

PLAY

REC/ITR

ST-BY

REC/ITR TIMER/REC

1-10

1. MAIN POWER (ON/OFF)

switches the set on or off.

2. STOP

Stops playback for DVD player.

3. PLAY

Starts playback for DVD player.

4. OPEN/CLOSE

Opens or closes the disc tray.

5. DISC TRAY

Places a disc on the disc tray.

6. LED (Light Emitting Diode) DISPLAY

7. CASSETTE COMPARTMENT

Inserts a video cassette tape here.

8. STOP/EJECT

stops the tape during playback or recording or ejects the tape.

DD / EE

(Programme Up/Down)

selects a programme or a menu item. switches the set on from standby.

FF / GG

(Volume Down/Up)

adjusts the volume. adjusts menu settings.

10. REC/ITR

starts a manual recording or instant timer recording.

11. POWER (

/ I)

switches the set on from standby or off to standby.

12. COMMUNICATOR SENSOR

Note : Only use the supplied Communicator.

(When you use others, they’ll be not able to function.)

13. HEADPHONE SOCKET (option)

Connect the headphone plug to this socket.

14. AUDIO/VIDEO IN SOCKETS (AV2)

Connect the audio/video out sockets of external equipment to these sockets.

S-VIDEO/AUDIO IN SOCKETS (S-Video) (option)

Connect the video out socket of an VCR to the S-VIDEO socket. Connect the audio out sockets of the VCR to the audio sockets as in AV2.

15. STANDBY / REC/ITR / TIMER REC INDICATOR

3-2

ADJUSTMENT INSTRUCTIONS

1. APPLICATION RANGE

These adjustment instructions is applied to MV-033A chassis.

2. Notes

2.1. Because this is a cold chassis, it is not necessary to use an isolation transformer. But operate it using a transformer between the power supply line and chassis input to prevent electric shock and to protect the test instrument.

2.2. All adjustment must be done in correct sequence. However, for the better productivity, it can be changed in pre-permitted range.

2.3. Environment conditions : If not specified, it must be done in following conditions.

1) Temperature : 25

cC ! 5 cC

2) Humidity : 65 % ! 10 %

2.4. Power supply of a SET which is adjusted is AC110-240V, 50/60Hz.(EU model : AC230V,50HZ)

2.5. If not specified, the receiver must be operated for more than 20 minutes prior to the adjustment.

2.6. Signal Receive the standard color signal. (65dB ! 1dB uV) LG standard signal means the digital pattern PAL-B/G 05CH.

3. DECK Line Adjustment.(VCR DECK Part)

3.1. P2/P3 Pre-Adjustment

3.1.1. Necessary Instrument

1) PAL SP Normal TAPE

2) OSCILLOSCOPE

3) 10:1 PROBE : 2 PIECES

4) SPECIAL NUT DRIVER (for P2/P3 Control)

3.1.2. Adjustment

1) Play the PAL standard Tape(SP).

2) Connect to J261(H/SW) the OSCILLOSCOPE(CH-1) on the MAIN1 PCB.

3) Connect to J219(RF) the OSCILLOSCOPE(CH-2) on the MAIN1 PCB.

4) With observing the RF envelope waveform, adjust P2, P3 until it becomes the waveform C.

5) Check the envelope waveform is in the maximum size by pressing the TRK UP(+).

3.2. CTL/AUDIO LEVEL ADJUSTMENT

3.2.1. NECESSARY INSTRUMENT

1. CTL TAPE

2. PAL SP Standard TAPE(for Audio level adjustment)

3. OSCILLOSCOPE

4. 10:1 PROBE : 2 PIECES

5. RMS METER(for Audio level adjustment)

3.2.2. CTL ADJUSTMENT

THIS ADJUSTMENT MUST BE DONE WHEN THE UNCONTROLLED DECK IS WAREHOUSED.

1) Connect the OSCILLOSCOPE to J101(CTL)

2) After playing the CTL control tape, make sure the CTL waveform range is From 1.5 :1 to 2.5 : 1. If it is out of range , adjust CTL waveform to the following procedures. ¤ If is over 2.5 :1, lower the head height.

After turning the height adjust screw counter-clockwise to adjust its level from 1.5 : 1 to 2 : 1. Check the tape location at P4. Readjust the TILT.(2:1)

¤ŁIf is under 1.5:1, heighten the head height.

After turning the height, adjust the screw clockwise to adjust its level from 2 : 1 to 2.5 : 1. Check the tape location of P4. Readjust the TILT.(2:1)

3) Play the standard tape and adjust the azimuth screw right and left by using the oscilloscope and level-meter to maximize the audio sound. Adjust the azimuth screw & the height adjust screw at the same time because they have mutual relationship. (Check CTL again after the adjustment) *A/C head adjustment order Height adjust screw->check the TILT->azimuth screw-> check CTL

<A> P2 POST ADJUSTMENT

<B> P3 POST ADJUSTMENT

<C> The Waveform after adjustment

TAKE- UP

REEL

AZIMUTH ADJUST SCEW

CAPSTAN

T/UP ARM

SUPPLY

REEL

DRUM

FE HEAD

TENTION ARM

TAKE- UP

REEL

AZIMUTH ADJUST SCEW

CAPSTAN

T/UP ARM

SUPPLY

REEL

DRUM

FE HEAD

TENTION ARM

TAKE- UP

REEL

AZIMUTH ADJUST SCEW

CAPSTAN

T/UP ARM

SUPPLY

REEL

DRUM

FE HEAD

TENTION ARM

X-Value Fixed Screw

X-Value Adjustment Hole

Tilt Adjustment screw

Height Adjustment Screw

PINCH - ROLLER

<Fig1> Adjustment Position

<Fig2> P2/ P3 Adjustment Waveform

CTL WAVEFORM

<Fig3>

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