LG 21FU6RLX Service Manual Download Page 3

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SAFETY PRECAUTIONS

Many electrical and mechanical parts in this chassis have special safety-related characteristics. These parts are identified by      in the
Schematic Diagram and Replacement Parts List. 
It is essential that these special safety parts should be replaced with the same components as recommended in this manual to prevent
X-RADIATION, Shock, Fire, or other Hazards. 
Do not modify the original design without permission of manufacturer.

General Guidance

An isolation 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 circuitry 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: 

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 position, 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 exposed 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 specified, 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

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.

1.5 Kohm/10W

To Instrument’s
exposed 
METALLIC PARTS

Good Earth Ground
such as WATER PIPE,
CONDUIT etc.

AC Volt-meter

IMPORTANT SAFETY NOTICE

0.15uF

Copyright©2008 LG Electronics.Inc. All right reserved.
Only for training and service purposes.

LGE Internal Use Only

Summary of Contents for 21FU6RLX

Page 1: ...AD THE SAFETY PRECAUTIONS IN THIS MANUAL North Latin America http aic lgservice com Europe Africa http eic lgservice com Asia Oceania http biz lgservice com Sep 2008 Printed in China P NO MFL51851001 CHASSIS CW62E MODEL 21FU6RLX MODEL 21FU6RLX T8 Internal Use Only ...

Page 2: ...s 4 Specifications 7 Adjustment Instructions 8 SVC Remocon 13 Trouble Shooting 14 Printed circuit board 17 Block Diagram 19 Exploded View 20 SVC Sheet Copyright 2008 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Page 3: ...ic 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 position connect one lead of ohm meter to the AC plug prongs tied together and touch o...

Page 4: ...ber in accordance with BOM 5 The receiver must be operated for about 20 minutes prior to the adjustment O2 6Khe W2 6Xh 7 1h J L g 7 1 g g g 3 5 g N H g 3 5h V4 0Yh I4 0Mhe Test method No 1 2 3 4 5 6 7 8 9 10 Item Receiving System Available Channel Input Voltage Market Screen Size Aspect Ratio Display Method Tuning System Operating Environment Storage Environment Remark Korea L America Philippine T...

Page 5: ...rity problem or not on R G B white Raster Then Fix screw of DY At this time be careful about inclination and DY should be fixed keeping horizontality f Check the TV in direction of EAST WEST SOUTH NORTH Adjust with supporting MAGNET when adjustment is not operated 3 2 2 Convergence Adjustment This adjustment should be operated at the best condition of FOCUS after finishing the PURITY adjustment a ...

Page 6: ... h e h h e h h e h h e 3L g g J5 e N1 g g 7H e 3Lg gJ5f V X f f W Yf V Xe eW Y f V K g O Yg V46K e O20Y g I4 0M h O2 6K h W20M e I46X g W M g I Xg W YfW fV X f W Y f7 f V Xf 7Hf J gN1f J5 fW g 3L e 7H f7 Y g N1 e f J H h e f 75 h e fJ Y h e f7 g e 3L e f J5 e N1 g g 7H e 3Lg gJ5f V X f f W Yf V Xf fW Y f V K g O Yg V46K e O20Y g I4 0M h until the color coordinates in High and Low color satisfies t...

Page 7: ...nes are straight 10 H BOW Adjust the left and right crooked line on upper and lower side 11 H PARALL ANGLE Adjust the vertical slope 12 SCORRECT S CORRECTION Adjust the lattice width of the Top Center Bottom to be the same W Xhf W X he W Xhe W X h W Xh W X g W Xg W X f f V Y f V Yg V Y g V Yh V Y h V Yhe V Y he V Yhf As being decided by DY value of the using CPT set as default Initial Data of usin...

Page 8: ...k Description WHITE STRETCH BLACK STRETCH BLACK STRATCH DEPTH DYNAMIC SKIN CONTROL VIDEO DEPENDENT CORING PEAKING FREQUENCY DELAY RATION POSITIVE NEGATIVE PEAKS RATION PRE AFTER SHOOT PEAK WHITE LIMITER DAC IF DEMODULATIOR CHROMA SENSITIVITY AUTO COLOR LIMITING Clamping delay 50 Clamping delay 60 Clamping Pulse Length Clamping Duration DEGAUSS 25 32 32 32 32 32 5 13 25 AGC RG GG BG BLO R BLO G CDL...

Page 9: ...VED RESERVED ENGLISH EAST EU ALL ENGLISH RUSSIAN RESERVED RESERVED RESERVED RESERVED RESERVED ENGLISH EU 7EA WEST EU ALL ENIGLISH GREEK RESERVED RESERVED RESERVED RESERVED ENGLISH INDONESIAN MALAY VIETNAMESE THAI ENGLISH GERMAN RUMANIAN POLISH HUNGARIAN CZECH RUSSIAN BULGARIAN ENGLISH RUSSIAN ENGLISH GERMAN FRENCH ITALIAN SPANISH NETHERLANDISH PORTUGUESE ENGLISH GERMAN FRENCH ITALIAN SPANISH NETHE...

Page 10: ...rating voice signal Kumi 5CH 25Ch O2 6K h W20Me I46X g W Mg I Xg W Y W2 6XeV X f W YeW MI X V Xf 7H e7HeN 1 eN1f J5f e e 3L e 7Hh 5 e N1 e hJ H f e h75g e g J Yg e 3LgW Y f J5 e N1f W Yg 7H e 3L eW Y O eJ5f V Xe7 W Yf V X W Y f V Kg O Yg V46Ke O20Y g I4 0M h Select a transmitted frequency in MENU OSD MENU SOUND X WAVE Set Frequency 87 7MHz O2 6Kh W20M eI46Xg W M gI X f W Ye W26X V Xf W Y eW XeV X ...

Page 11: ... Internal Use Only Power Input MEMORY CHANNEL SOUND MUTE PSM XD SSM TORBO SOUND AVL BALANCE ON OFF TIME AUTO SLEEP CHILD LOCK DEGAUSS EYE TILT BLUE BACK BOOSTER 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 ITEM No Shipping condition OFF TV Refer to CH MEMORY Management 30 STEPS OFF DYNAMIC ON FLAT OFF OFF 0 OFF OFF OFF OFF OFF 0 OFF OFF Remarks OPTION OPTION OPTION OPTION PSM CONTRAST BRIGHT CO...

Page 12: ... OK Check the waveform at pin 6 of IC601 Check Replace IC601 NO OK Check the waveform at pin 1 2 14 15 of IC601 Check Replace R823 D826 Check the Heater voltage of CPT 6 6 4 Vrms Check R G B out of CPT board Check IC901 P402A Check 190V line of CPT Board if no problem check and Replace Check the Heater pulse of FBT T402 Check RF901 P903C P903B FR401 Check FBT T402 Check HV Screen voltage of CPT Ch...

Page 13: ... Check Replace T402 Check the voltage pin4 of IC810 Check Replace IC810 IC802 Q830 Check Fuse and Diode of secondary Load of SMPS trans T802 Check the B at D829 cathode OPEN Check Replace DB801 NO Check Replace Fuse and IC810 NO OK NO Normal Abnormal Check Replace Q402 Check Replace T401 Check Replace Q401 Check Q402 collector waveform Check Replace IC11 NO OK Copyright 2008 LG Electronics Inc All...

Page 14: ...n3 Reset Voltage Check IC11 pin 83 84 85 R G B out Check SMPS Trans Secondary Voltage Go to No sound picture OK Check the waveform pin73 H out Check IC11 pin 83 84 85 R G B out Check receiving system in MENU execute Auto Program Does the auto Program operate properly Store on manual program MENU Copyright 2008 LG Electronics Inc All right reserved Only for training and service purposes LGE Interna...

Page 15: ... 15 PRINTED CIRCUIT BOARD MAIN Copyright 2008 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Page 16: ... 16 LED PRE AMP CONTROL Copyright 2008 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Page 17: ... 17 BLOCK DIAGRAM Copyright 2008 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Page 18: ...D VIEW It is essential that these special safety parts should be replaced with the same components as recommended in this manual to prevent X RADIATION Shock Fire or other Hazards Do not modify the original design without permission of manufacturer IMPORTANT SAFETY NOTICE 400 943 112 170 150 913 520 504 P801 Copyright 2008 LG Electronics Inc All right reserved Only for training and service purpose...

Page 19: ...P N EBY31683802 080201 ...

Page 20: ...SVC SHEET EBY31683802 S ...

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