General Guidance

An lsolation Transformer should always be used during the servicing of a receiver whose chassis is not isolated from the AC power line. Use a transformer of adequate power rating as this protects the technician from accidents resulting in personal injury from electrical shocks.

It will also protect the receiver and it's components from being damaged by accidental shorts of the circuitary that may be inadvertently introduced during the service operation.

If any fuse (or Fusible Resistor) in this TV receiver is blown, replace it with the specified.

When replacing a high wattage resistor (Oxide Metal Film Resistor, over 1W), keep the resistor 10mm away from PCB.

Keep wires away from high voltage or high temperature parts.

Due to high vacuum and large surface area of picture tube, extreme care should be used in handling the Picture Tube. Do not lift the Picture tube by it's Neck.

X-RAY Radiation

Warning:

The source of X-RAY RADIATION in this TV receiver is the High Voltage Section and the Picture Tube.

For continued X-RAY RADIATION protection, the replacement tube must be the same type tube as specified in the Replacement Parts List.

To determine the presence of high voltage, use an accurate high impedance HV meter.

Adjust brightness, color, contrast controls to minimum. Measure the high voltage.

The meter reading should indicate

23.5 !1.5KV: 14-19 inch, 26!1.5KV: 19-21 inch,

29.0!1.5KV: 25-29 inch, 30.0 ! 1.5KV: 32 inch

If the meter indication is out of tolerance, immediate service and correction is required to prevent the possibility of premature component failure.

Before returning the receiver to the customer,

always perform an AC leakage current check on the exposed metallic parts of the cabinet, such as antennas, terminals, etc., to be sure the set is safe to operate without damage of electrical shock.

Leakage Current Cold Check(Antenna Cold Check)

With the instrument AC plug removed from AC source, connect an electrical jumper across the two AC plug prongs. Place the AC switch in the on positioin, connect one lead of ohm-meter to the AC plug prongs tied together and touch other ohm-meter lead in turn to each exposed metallic parts such as antenna terminals, phone jacks, etc.

If the exposed metallic part has a return path to the chassis, the measured resistance should be between 1M??? and 5.2M???. When the exposed metal has no return path to the chassis the reading must be infinite.

An other abnormality exists that must be corrected before the receiver is returned to the customer.

Leakage Current Hot Check (See below Figure) Plug the AC cord directly into the AC outlet.

Do not use a line Isolation Transformer during this check.

Connect 1.5K/10watt resistor in parallel with a 0.15uF capacitor between a known good earth ground (Water Pipe, Conduit, etc.) and the exposed metallic parts.

Measure the AC voltage across the resistor using AC voltmeter with 1000 ohms/volt or more sensitivity.

Reverse plug the AC cord into the AC outlet and repeat AC voltage measurements for each esposed metallic part. Any voltage measured must not exceed 0.75 volt RMS which is corresponds to 0.5mA.

In case any measurement is out of the limits sepcified, there is possibility of shock hazard and the set must be checked and repaired before it is returned to the customer.

Leakage Current Hot Check circuit

AC Volt-meter

1.5 Kohm/10W

CANADA: LG Electronics Canada, Inc. 550 Matheson Boulevard East Mississauga, Ontario L4Z 4G3

CALIBRATION

Digital Audio

RF Connectors: Cable, Antenna Used to connect cable or antenna signals to the televi- sion, either directly or through your cable box.

Monitor Out Connects to a sec- ond TV or Monitor.

Variable Audio Out Used to connect either an external amplifier, or add a sub-woofer to your surround sound sys- tem.

Left/Right Audio

Used for stereo sound from various types of equipment.

Side Connections Panel

There are four jacks on the lower-right front side of your TV that make connecting Audio/Video devices like video games and camcorders very simple.

The jacks are like those found on the back jack connection panel. This means that most equipment that connects to those types of jacks on the rear jackpack, may be connected to the Side connection panel (FRONT VIDEO).

To use the Side jacks as the signal source, select them using Input source menu as described on page 25. They will be named ???front Video??? in the Input source menu.

When you select Side video or Side S-Video, the Front Audio inputs are automatically select- ed as well.

Do not connect to both Video and S-Video at the same time. Connect either Video or S- Video only.

S-Video

A connection available on some very high-end equipment that provides bet- ter picture quality than video input.

Video in

Connects the video signals from any piece of equipment.

Side A/V Panel

VIDEO-S

IN VIDEO

L/MONO

AUDIO

R

FRONT VIDEO

Left/Right Audio

Used for stereo sound from various types of equipment.

MODE

Selects the remote operating mode: TV, VCR, Cable, DVD or Satellite. Select other operating modes, for the remote to oper- ate external devices.

TV INPUT

Selects: TV and CATV.

TV/VIDEO

Selects: Antenna, Cable, Video1, Video2, Front video, Component 1-2 and HDMI/DVI input sources.

MUTE

Switches the Mute or the EZ mute. Mute: The sound is off. EZ mute: The sound is off, and the caption is display.

EZ SOUND

Adjusts the factory preset picture according to the room.

RATIO

Changes the aspect ratio.

FREEZE

Captures and freezes the currently-viewed picture.

THUMBSTICK

Allows you to navigate the on-screen menus and to adjust the system set- tings and preferences, by moving to an option withF ED G and selecting the high- lighted option with .

MENU

Brings up the main menu to the screen.

MODE INDEX POWER

INPUT TV/VIDEO COMP1

COMP2 HDMI FRONT

1 2 3

4 5 6

7 8 9

RATIO FREEZE SAP SURROUND

INFO TIMER CC SIGNAL

PLAY PAUSE STOP RECORD

MODE INDICATOR

LIGHTS

Show active remote mode every time any button is pressed.

INDEX

Switches LED Display on or off.

COMP1

Selects the Component 1 input source.

FAV

Use to scroll the FAV chan- nel list.

EZ PIC

Adjusts the factory preset picture depend- ing on the viewing environment.

SURROUND

Selects : Off, 3D

EchoSound System and

SRS TruSurround XT.

SAP

Selects MTS sound: Mono,

Stereo, and SAP.

Change the audio language in

DTV mode.

CC

Lets you select a closed caption mode for displaying captioning information when provided for DTV/Analog signal.

EXIT

Clears all on-screen dis- plays and returns to TV viewing from any menu.

COMP2

Selects the Component 2 input source.

HDMI

Selects the HDMI input source.

NUMBER KEYPAD

For direct channel selection and programming functions.

DASH(-)

Is used to enter a program number for multiple program channels such as 2-1,2-2,etc.

VOLUME UP/DOWN

Increases/decreases the sound level.

INFO

When you watch the TV, dis- plays information on top of the screen. Not available in Component 1-2 and HDMI/DVI.

TIMER

Lets you select the amount of time before your TV turns itself off automatically.

RECORD, PAUSE, REW,

FFWD, PLAY, STOP

Control the functions on your VCR.

RATIO FREEZE SAP SURROUND

INFO TIMER CC SIGNAL

POWER

Turns your TV or any other programmed equipment on or off, depending on mode.

FRONT

Selects the front video input source.

FLASHBK

Use to scroll the recent chan- nel list.

CHANNEL UP/DOWN

Scrolls through available chan- nels present in EZ Scan memory.

SIGNAL

Displays the digital signal strength.

ENTER

When in the menu system and other on-screen dis- plays, selects highlighted options.

SKIP LEFT/RIGHT

Playing CDs: Selects songs.

Playing DVDs: Selects movie chapters.

1. Application Object

These instructions are applied to the AC-02SA/C chassis.

2.Notes

(1)Because this is not a hot chassis, it is not necessary to use an isolation transformer. However, the use of an isolation transformer will help protect test instruments.

(2)Adjustments must be done in the correct order.

(3)The input voltage of the receiver must remain at 120V??10% while adjusting.

(4)The receiver must be operated for about 20 minutes prior to the adjustment.

[Never operate the set over 10 minutes with a still picture because a fluorescent material may get damage.

3.Focus Adjustment

A

(1) Set Picture condition to ???APC ON???.

CONTRAST : 100

BRIGHT : 50

APC ON TINT : 55

COLOR : 0

SHARPNESS : 55

(2)Set the Aspect ratio to Wide Mode.

(3)Receive a Cross Hatch Pattern, adjusting the FOCUS Knob on the flyback transformer for the best focus in the area designated ???A??? above.

[ Heat run over 15 minutes before adjustment.

4-2. Adjustment

(1)Select EZ Adjust 3. CUT-OFF, by pressing the ADJ key on the SVC Remote control.

When it enters to adjustment mode, the pattern from a signal generator is being selected, it becomes with Normal image 16:9 and the CUT-OFF DRIVE data setting 31.

(2)Connect the oscilloscope ground lead to GND on the CPT board and the probe to the GK pin connector of the CPT socket.

Using the SCREEN knob on the Flyback Transformer, adjust the black level voltage to 180??2V.

180??2V

CUT-OFF Adjustment

(SCREEN voltage adjustment OSCILLOSCOPE, 100:1 PROBE, VOLTS/DIV : 0.5V/DIV SEC/DIV : 5us, The TRIGGER MODE it puts in the TV-H)

5. Deflection Adjustment

5-1. Preliminary Steps

Select EZ Adjust 1. Raster, Cent, H/V Size by using the ADJ key on the SVC Remote control.

In the adjustment mode a Digital Pattern signal signal is displayed.

5-2. Raster V-Center(V.Center) Adjustment

Select 62. V-Postition in the adjustment mode and adjust it to position the vertical center line in vertical center of the CPT.

5-3. Vertical Deflection Size Adjustment

(Overscan : 10%)

(1)Select 59. V-SIZE in the adjustment mode.

(2)Adjust until the smaller inscribed circle coincides with the outer frame of screen.

(3)Select 95. LO-VLIN or 94. UP-VLIN and adjust until the larger inscribed circle coincides with the outer frame of screen.

5-4. Raster H-center(H.CENTER) Adjustment

Select 77. H Postion in the adjustment mode and adjust until left and right screen are symmetrically equal.

5-5. Horizontal Deflection Size Adjustment

(1)Reduce 66 H-Size to verify screen protection (overscan) on the right and left sides.

(2)Adjust the horizontal size, using a test pattern.

5-6. Horizontal Pincushion Adjustment

(1)Select EZ Adjust 2. Pin-Cushion by pressing the ADJ key on the SVC Remote control.

(2)Select PIN-PHASE, PIN-AMP, AFC-BOW, AFC-ANGLE, UP-CPIN, LO-CPIN in the adjustment mode and adjust until there is no Pincushion distortion or trapezoid distortion on the screen.

6.Component AD9883A Offset/Gain Adjustment

6-1. Test equipment

(1)SVC Remote Control,

(2)801GF(802B, 802F, 802R) pattern generator

<1080I Hoz30Bar Pattern>

7. White Balance Adjustment

Perform the screen adjustment first.

Color Temp must be adjusted from Medium Mode.

(The image condition must be adjusted from Normal condition) Manual adjustment is also possible by the following sequence.

(1)Receive White Pattern.

(2)Set screen size to wide mode

(3)Select EZ Adjust 4. White Balance on the SVC Remote control.

(4)Adjustment

1.Set an image with Normal image.

2.Adjust R-DRIVE and B-DRIVE data so the color coordinates in High light are the values in Table below. (bright level : 25Ft_L)

3.Adjust ???CONTRAST??? and ???BRIGHT??? so the bright level is 4.5??0.5Ft_L.

4.Adjust R-CUT and B-CUT data so the color coordinates in Low light are the values in Table below.

5.Repeat 1 ~ 4 until the color coordinates in High and Low color satisfies the Table.

6.Check the adjusted color coordinates with the white balance meter.

High Light : x=287!3, y=293!3

Low Light : x=287!3, y=293!3

Color temperature : 9,000K!1000(-5MPCD)

[The White Balance it executes from automatic adjustment hour Normal image condition.

Start adjustments from initial setting of R.DRIVE=31, G.DRIVE=31, B.DRIVE=31, R.CUT=31, G.CUT=31, B.CUT=31.

6-2. Preliminary Steps

(1)Turn the power supply on.

(2)Enter the Component mode.

(3)Receive the 1080I, Hoz30Bar Pattern of the 801GF.

6-3. ADC Offset Adjustment

(1)After receiving a signal press the ADJ Key on the SVC Remote Control repeatedly to acess the Adjustment mode.

(2)#9. Set Adjustment will set the AD9883A automatically.

8. Sub Bright, TINT, COLOR Adjustment

8-1. Sub Bright Adjustment

0 1 2 3 4 5 6 7 8 9

US14CH

Caution:

Convergence and Purity have been factory aligned. Do not attempt to tamper with these alignments.

However, the effects of adjacent receiver components, or replacement of picture tube or deflection yoke may require the readjustment of purity and convergence.

5.Reconnect the internal degaussing coil.

6.Position the beam bender locking rings at the 9 o'clock position and the other three pairs of tabs (2,4 and 6 pole magnets) at the 12 o'clock position.

?? Purity Adjustment

This procedure DOES NOT apply to bonded yoke and picture tube assemblies.

The instrument should be at room temperature (60 degrees F or above) for six (6) hours and be operating at low beam current (dark background) for approximately 20 to 30 minutes before performing purity adjustments.

CAUTION: Do not remove any trim magnets that may be attached to the bell of the picture tube.

1.Remove the AC power and disconnect the internal degaussing coil.

2.Remove the yoke from the neck of the picture tube.

3.If the yoke has the tape version beam bender, remove it and replace it with an adjustable type beam bender (follow the instructions provided with the new beam bender)

4.Replace the yoke on the picture tube neck, temporarily remove the three (3) rubber wedges from the bell of the picture tube and then slide the yoke completely forward.

7.Perform the following steps, in the order given, to prepare the receiver for the purity adjustment procedure.

a.Face the receiver in the "magnetic north" direction.

b.Externally degauss the receiver screen with the television power turned off.

c.Turn the television on for approximately 10 seconds to perform internal degaussing and then turn the TV off.

d.Unplug the internal degaussing coil. This allows the thermistor to cool down while you are performing the purity adjustment. DO NOT MOVE THE RECEIVER FROM ITS

"MAGNETIC NORTH" POSITION.

e.Turn the receiver on and obtain a red raster by increasing the red bias control (CW) and decreasing the bias controls for the remaining two colors (CCW).

f.Attach two round magnets on the picture tube screen at 3 o'clock and 9 o'clock positions, approximately one (1) inch from the edge of the mask (use double-sided tape).

1.ADJUST YOKE Z-AXIS FIRST

TO GET EQUAL BLUE

COLOR CIRCLES

MAGNETS

RED

8.Referring to above, perform the following two steps:

a.Adjust the yoke Z-axis to obtain equal blue circles.

b.Adjust the appropriate beam bender tabs to obtain correct purity (four equal circles).

9.After correct purity is set, tighten the yoke clamp screw and remove the two screen magnets.

10.Remove the AC power and rotate the receiver 180 degrees (facing "magnetic south").

11.Reconnect the internal degaussing coil.

12.Turn the receiver on for 10 seconds (make sure the receiver came on) to perform internal degaussing, and then turn the receiver off.

13.Unplug the internal degaussing coil.

14.Turn the receiver on and check the purity by holding one (1) round magnet at the 3 o'clock and a second round magnet at 9 o'clock position. If purity is not satisfactory, repeat steps 8 through 14.

15.Turn off the receiver and reconnect the internal degaussing coil.

?? Convergence Adjustment

Caution: This procedure DOES NOT apply to bonded yoke and picture tube assemblies.

Do not use screen magnets during this adjustment procedure. Use of screen magnets will cause an incorrect display.

1.Remove AC power and disconnect the internal degaussing coil.

2.Apply AC Power and set the brightness to the Picture Reset condition. Set the Color control to minimum.

3.Make horizontal line.

4.Adjust the Red, Green and Blue Bias controls to get a dim white line.

2 .ADJUST BEAM BENDER 2 POLE

MAGNET TO GET FOUR EQUAL

COLOR CIRCLES

RED

5.Restore the screen by removing the horizontal line.

6.Reconnect the internal degaussing coil and apply AC power.

7.Turn the receiver on for 10 seconds to perform internal degaussing and then turn the receiver off again.

8.Unplug the internal degaussing-coil.

9.Turn the receiver on, connect a signal generator to the VHF antenna terminal and apply a crosshatch signal.

Caution: During the convergence adjustment procedure, be very careful not to disturb the purity adjustment tabs. Purity should be confirmed before proceeding with the convergence adjustments.

Note: Make sure the focus is set correctly on this instrument before proceeding with the following adjustment.

10.Converge the red and blue vertical lines to the green vertical line at the center of the screen by performing the following steps (below TABLE).

a.Carefully rotate both tabs of the 4-pole ring magnet simultaneously in opposite directions from the 12 o'clock position to converge the red and blue vertical lines.

b.Carefully rotate both tabs of the 6-pole ring magnet simultaneously in opposite directions form the 12 o'clock position to converge the red and blue (now purple) vertical lines with the green vertical line.

11.Converge the red and blue horizontal with the green line at the center of the screen by performing the following steps. (below TABLE)

a.Carefully rotate both tabs of the 4-pole ring magnet simultaneously in the same direction (keep the spacing between the two tabs the same) to converge the red and blue horizontal lines.

b.Carefully rotate both tabs of the 6-pole ring magnet simultaneously in same direction (keep the spacing between the two tabs the same) to converge the red and blue (now purple) horizontal lines with the green horizontal line.

c.Secure the tabs previsouly adjusted by locking them in place with the locking tabs on the beam bender.

UP/DOWN ROCKING OF THE YOKE CAUSES

OPPOSITE ROTATION OF RED AND BLUE

RASTERS

GREEN

LEFT/RIGHT ROCKING OF THE YOKE

CAUSES OPPOSITE SIZE CHANGE OF

THE RED AND BLUE RASTERS

GREEN

12.While watching the 6 o'clock positions on the screen, rock the front of the yoke in a vertical (up/down) direction to converge the red and blue vertical lines. (Fig upper left)

13.Temporarily place a rubber wedge at the 12 o'clock position to hold the vertical position or the yoke.

14.Check the 3 o'clock and 9 o'clock areas to confirm that the red and blue horizontal lines are converged.

If the lines are not converged, slightly offset the vertical tilt of the yoke (move the rubber wedge if necessary) to equally balance the convergence error of the horizontal lines at 3 o'clock and 9 o'clock and the vertical lines at 6 o'clock and 12 o'clock.

15.Place a 1.5 inch piece of glass tape over the rubber foot at the rear of the 12 o'clock wedge.

16.While watching the 6 o'clock and 12 o'clock areas of the screen, rock the front of the yoke in the horizontal (left to right) motion to converge the red and blue horizontal lines.

(Fig. upper right)

17.Temporarily place a rubber wedge at the 5 o'clock and 7 o'clock positions to hold the horizontal position of the yoke.

18.Check the 3 o'clock and 9 o'clock areas to confirm that the red and blue vertical lines are converged. If the lines are not converged, slightly offset the horizontal tilt of the yoke (move the temporary rubber wedges if necessary) to equally balance the convergence error of the horizontal lines at 6 o'clock and 12 o'clock and the vertical lines at 3 o'clock and 9 o'clock.

19.Using a round magnet confirm purity at the center, right and left sides and corners. See Purity Adjustment Procedure.

20.Reconfirm convergence and apply a 1.5 inch piece of glass tape over the rubber foot at the rear of the 5 o'clock and the 7 o'clock wedges.