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- 5 -

c. Qulckly move the soldering iron tip to the junction of the

component lead and the printed circuit foil, and hold it
there only until the solder flows onto and around both the
component lead and the foil.

CAUTION: 

Work quickly to avoid overheating the circuit

board printed foil.

d. Closely inspect the solder area and remove any excess

or splashed solder with a small wire-bristle brush.

IC Remove/Replacement

Some chassis circuit boards have slotted holes (oblong) through
which the IC leads are inserted and then bent flat against the
circuit foil. When holes are the slotted type, the following
technique should be used to remove and replace the IC. When
working with boards using the familiar round hole, use the
standard technique as outlined in parapraphs 5 and 6 above.

Removal

1.  Desolder and straighten each IC lead in one operation by

gently prying up on the lead with the soldering iron tip as the
solder melts.

2.  Draw away the melted solder with an anti-static suction-

type solder removal device (or with solder braid) before
removing the IC.

Replacement

1.  Carefully insert the replacement IC in the circuit boare.
2.  Carefully bend each IC lead against the circuit foil pad and

solder it.

3.  Clean the soldered areas with a small wire-bristle brush.

(It is not necessary to reapply acrylic coating to the areas).

"Small-Signal" Discrete Transistor
Removal/Replacement

1.  Remove the defective transistor by clipping its leads as

close as possible to the component body.

2.  Bend into a "U" shape the end of each of three leads

remaining on the circuit board.

3.  Bend into a "U" shape the replacement transistor leads.
4.  Connect the replacement transistor leads to the

corresponding leads extending from the circuit board and
crimp the "U" with long nose pliers to insure metal to metal
contact then solder each connection.

Power Output, Transistor Device
Removal/Replacement

1.  Heat and remove all solder from around the transistor leads.
2. Remove the heatsink mounting screw (if so equipped).
3.  Carefully remove the transistor from the heat sink of the

circuit board.

4.  Insert new transistor in the circuit board.
5. Solder each transistor lead, and clip off excess lead.
6.  Replace heatsink.

Diode Removal/Replacement

1.  Remove defective diode by clipping its leads as close as

possible to diode body.

2.  Bend the two remaining leads perpendicula y to the circuit

board.

3.  Observing diode polarity, wrap each lead of the new diode

around the corresponding lead on the circuit board.

4.  Securely crimp each connection and solder it.
5. Inspect (on the circuit board copper side) the solder joints of

the two "original" leads. If they are not shiny, reheat them
and if necessary, apply additional solder.

Fuse and Conventional Resistor
Removal/Replacement

1.  Clip each fuse or resistor lead at top of the circuit board

hollow stake.

2.  Securely crimp the leads of replacement component around

notch at stake top.

3.  Solder the connections.

CAUTION: 

Maintain original spacing between the replaced

component and adjacent components and the circuit board
to prevent excessive component temperatures.

Circuit Board Foil Repair

Excessive heat applied to the copper foil of any printed circuit
board will weaken the adhesive that bonds the foil to the circuit
board causing the foil to separate from or "lift-off" the board.
The following guidelines and procedures should be followed
whenever this condition is encountered.

At IC Connections

To repair a defective copper pattern at IC connections use the
following procedure to install a jumper wire on the copper
pattern side of the circuit board. (Use this technique only on IC
connections).

1.  Carefully remove the damaged copper pattern with a sharp

knife. (Remove only as much copper as absolutely
necessary).

2.  carefully scratch away the solder resist and acrylic coating

(if used) from the end of the remaining copper pattern.

3.  Bend a small "U" in one end of a small gauge jumper wire and

carefully crimp it around the IC pin. Solder the IC connection.

4.  Route the jumper wire along the path of the out-away

copper pattern and let it overlap the previously scraped end
of the good copper pattern. Solder the overlapped area and
clip off any excess jumper wire.

At Other Connections

Use the following technique to repair the defective copper
pattern at connections other than IC Pins. This technique
involoves the installation of a jumper wire on the component
side of the circuit board.

1.  Remove the defective copper pattern with a sharp knife.

Remove at least 1/4 inch of copper, to ensure that a
hazardous condition will not exist if the jumper wire opens.

2.  Trace along the copper pattern from both sides of the

pattern break and locate the nearest component that is
directly connected to the affected copper pattern.

3.  Connect insulated 20-gauge jumper wire from the lead of

the nearest component on one side of the pattern break to
the lead of the nearest component on the other side.
Carefully crimp and solder the connections.

CAUTION: 

Be sure the insulated jumper wire is dressed so

the it does not touch components or sharp edges.

Содержание RF/RT-14/21CA80M/MX

Страница 1: ...ERVICING THE CHASSIS READ THE SAFETY PRECAUTIONS IN THIS MANUAL CHASSIS MC 019A MODEL RF RT 20 21CA80VE VQ VW MODEL RF RT 14 21CA80M MX MODEL CF 21CA810EX RF 21CB90VQ website http biz LGservice com e mail http www LGEservice com techsup html ...

Страница 2: ...Servicing Precautions 4 Specifications 6 Description of Controls 7 Disassembly Instructions 10 Adjustment 11 Purity Convergence Adjustment 14 Block Diagram 17 Exploded View 18 20 Exploded View Parts List 19 21 Replacement Parts List 22 SVC Sheet ...

Страница 3: ...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...

Страница 4: ...s are integrated circuits and some fieldeffect transistors and semicounductor chip components The following techniques should be used to help reduce the incidence of component damage caused by static by static electricity 1 Immediately before handling any semiconductor component or semiconductor equipped assembly drain off any electostatic charge on your body by touching a known earth ground Alter...

Страница 5: ...the corresponding lead on the circuit board 4 Securely crimp each connection and solder it 5 Inspect on the circuit board copper side the solder joints of the two original leads If they are not shiny reheat them and if necessary apply additional solder Fuse and Conventional Resistor Removal Replacement 1 Clip each fuse or resistor lead at top of the circuit board hollow stake 2 Securely crimp the ...

Страница 6: ...SD On Screen Display EASY MENU O Voice coil impedance 8 ohm O Sound output 7W 2 MAX Dual Stereo A2 NICAM Option O External connection Head Phone Jack A V in 2 PERI Connector Full Scart 1 DVD in O External In Output Audio In 0 5Vrms 3dB over 10Kohm Audio Out 0 5Vrms 3dBb below 1Kohm Video In Out 1Vp p 3dB 75ohm DVD In Y 1Vp p 3dB Pb Pr 0 7Vp p 3dB O Feature Auto programme Manual programme CSM Color...

Страница 7: ...s a programme or a menu item switches the set on from standby scans programmes automatically F F G G Volume Up Down adjusts the volume adjusts menu settings OK accepts your selection or displays the current mode 6 Q VIEW returns to the previously viewed programme selects a favorite programme 7 TELETEXT BUTTONS option These buttons are used for teletext For further details see the Teletext section ...

Страница 8: ...e used for teletext only TELETEXT models or programme edit Battery installation The remote control handset is powered by two AAA type batteries To load the batteries turn the remote control handset over and open the battery compartment Install two batteries as indicated by the polarity symbols and marked inside the compartment Note To avoid damage from possible battery leakage remove the batteries...

Страница 9: ... AUDIO VIDEO IN SOCKETS AV option Connect the audio video out sockets of external equipment to these sockets Note If both the input jacks on the front side panel and back panel have been connected to external equipments simultane ously only the input jacks on the front side panel can be received 7 HEADPHONE SOCKET option Connect the headphone plug to this socket 8 TURBO SOUND PICTURE option switch...

Страница 10: ...oval 1 Pull out the CPT board from the CPT neck 2 Place the front cabinet on soft material not to mar the front surface or damage control knobs 3 Remove 5 screws securing the picture tube mounting brackets to the front cabinet 4 Carefully separate CPT from the front cabinet PICTURE TUBE HANDLING CAUTION Due to high vacuum and large surface area of picture tube great care must be exercised when han...

Страница 11: ... SVC mode 2 Press the Yellow button several times to find OPTION 1 or OPTION 2 3 Input the correspond OPTION data referring to Table below with the numeric buttons 4 Press the OK V button to memorize the data Table 1 OPTION 1 Function Table 2 OPTION 2 Function Table 3 OPTION 3 Function ADJUSTMENT 21 FCD 12 FLAT 14 16 CPT 8 15 CPT 10 FLAT 20 21 CPT 12 CDL Data Remark 0 1 0 1 0 1 0 1 0 1 SCART TOP 2...

Страница 12: ...Press Channel UP DOWN button for desirous function adjustment 5 Adjust VOL or VOL button in each status of RG BG for X 272 8 Y 288 8 with color analyzer Europe Model X 288 8 Y 295 X 272 8 11 000K 7 Press the OK V button to memorize the data Test Point AGC TP C101 Adjust Remote Controller Tuner P N Marker AGC Voltage 6700VPF009G LG Innotek W S TUNER 2 7 0 05V 6700VPF016A DAEWOO W S TUNER 2 7 0 05V ...

Страница 13: ... is in accord with geometric horizontal center of the CPT VA Vertical Amplitude Adjust so that the circle of a digital circle pattern may be located within the effective screen of the CPT SC Vertical S Correction Adjust so that all distance between each horizontal lines are to be the same VS Vertical Shift Adjust so that the horizontal center line of a digital circle pattern is in accord with geom...

Страница 14: ...mpletely forward 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 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 recei...

Страница 15: ...e internal degaussing coil 9 Turn on the receiver 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 are accidentally move purity should be confirmed before proceeding with the convergence adjustments Note Make sure the focus is set correctly on this instr...

Страница 16: ... 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 equ...

Страница 17: ...7266 97 STEREO Sound Max SOUND AMP TDA7266 97 IC131 5V REG Option Part IIC Bus Line TDA9381 Non TXT Audio Mono TV OUT 28 33 21 22 38 Sound Trap Part Video OUT TV MNT OUT 50 42 51 53 STEREO B01K A13P MONO B01L 10 12 9 5 3 9 8 10 2 6 14V 1 ST BY TRANS 3W Opt SPK L OUT 24 25 47 44 AUDIO AM IN L L Only 30 39 31 40 28 30 14 39 8V From IC844 14 39 39 3 3V Reg 5V From IC842 3 3V 8V From IC844 IC844 8V RE...

Страница 18: ... 18 EXPLODED VIEW 913 112 153 170 150 174 330 320 310 120 121 530 340 700 400 943 350 354 520 550 ...

Страница 19: ...ON TURBO 350 3750V00021A 3750V00021A RACK BASE ASSY 354 4980V00035A 4980V00035A SUPPORTER BASE NON SWIVEL 400 3809V00A42B 3809V00285A 3809V00285A BACK COVER ASSY 3809V00285D 3809V00285D BACK COVER ASSY JACK 3809V00A42D 3809V00285B BACK COVER ASSY SCART ESSALEM 3809V00285C 3809V00285C BACK COVER ASSY SCART 520 6871VMM754T 6871VMM855R 6871VMM855S PWB ASSY MAIN 6871VMM855U PWB ASSY MAIN HAFIDH 6871VM...

Страница 20: ... 20 EXPLODED VIEW CB90 913 112 153 170 150 174 310 700 540 340 350 354 330 320 121 120 520 400 943 300 122 ...

Страница 21: ... SPRING KNOB 330 5020V00800A BUTTON POWER RT 21CB90 ABS HF 380 1KEY EXPORT SHAHAB 340 5020V00802A BUTTON TURBO RT 20CB90 ABS HF 380 2KEY EXPORT SHAHAB 350 3750V00046B RACK BASE ASSY RF 21CB90VQ PPL 354 4980V00035A SUPPORTER BASE EVA NONE 400 3809V00345B BACK COVER ASSEMBLY RF 21CB90VQ PPL 1PHONE 520 6871VMMP38Q PWB PCB ASSEMBLY MAIN MC019A RF 21CB90VQ KMLLKS2 SHAHAB PPL 540 6871VSM360R PWB PCB ASS...

Страница 22: ... D2SBA60 STK HOLDER LED MODULE ASSY 4PIN DIODE ZENERS MTZJ9 1B TP ROHM K DO34 0 5W DIODE ZENERS GDZJ5 1B TP GRANDE DO34 0 5W LOCA NO PART NO DESCRIPTION ZD441 ZD442 ZD443 ZD501 ZD601 ZD901 Q01 Q102 Q103 Q211 Q212 Q213 Q214 Q215 Q216 Q301 Q402 Q442 Q551 Q552 Q553 Q554 Q555 Q571 Q621 Q651 Q653 Q801 Q802 Q806 QV01 QV02 C01 C02 C03 C04 C05 C07 C21 C51 C101 C102 C107 C109 C110 C111 C112 C113 0DZ620009A...

Страница 23: ...C541 C542 C548 C549 C551 C561 C573 C574 C593 C594 C595 C601 C602 C603 C605 C606 C607 C612 C631 C632 C633 C634 C635 C636 C637 C638 C639 C640 C641 C642 C643 C644 C645 C646 C653 C655 C801 C802 C803 C804 C805 C806 0CN1030F679 0CE225CK636 0CQ1041N509 0CN1030F679 0CF4741L438 0CN2230H949 0CN2230H949 0CN2230H949 0CN8210K519 0CQ4721N509 0CX4700K409 0CE107DD618 0CE476DF618 0CQ1021N509 0CE475DK618 0CQ1041N50...

Страница 24: ...C253 C255 C546 20 D813 FR441 FR442 14 20 FR443 FR802 FR901 J30 J33 J39 J67 J81 J101 J149 J154 L01 L10 L251 L252 L631 R01 R02 R03 R04 R05 R06 R07 0LA0102K119 0LA0102K119 0LA0681K119 0LA0561K119 0LA0102K049 150 C02F 0LA0101K119 0LA0681K119 0LA0681K119 0LA0681K119 6174V 6002K 6174Z 6040C 6170VC0003C 151 A13P 6170VMCB01K 0RD4702F609 0RD4702F609 0RD1503F609 0RD1103F609 0RS0272H609 0RF0470J607 0RF0121K6...

Страница 25: ...2 R223 R224 R225 R226 R227 R228 R251 R254 R255 R301 R302 20 R304 20 R305 R306 20 R307 20 R310 R311 R312 R313 R401 R402 R442 R444 R446 R447 14 20 R450 R451 14 21 R453 14 20 R455 R456 14 20 R501 R502 0RD1801F609 0RD4702F609 0RD1201F609 0RD4701F609 0RD3901F609 0RD1201F609 0RD3901F609 0RD4701F609 0RD1201F609 0RD1801F609 0RD1300F609 0RD2200H609 0RD2200A609 0RD2200H609 0RD2200A609 0RD0101F609 0RN1501F40...

Страница 26: ...812 R813 R815 R816 R901 R902 R903 R904 R905 R906 R907 R908 R909 R910 R911 R912 RC801 RV01 RV02 SW01 SW02 SW03 SW04 SW05 SW06 SW07 SW08 SW801 FB801 FB802 FB803 L611 T551 T552 T553 T801 0RD2000F609 0RD2701F609 0RD2201F609 0RD1001F609 0RD4701F609 180 A01P 0RD2401F609 0RD4701F609 0RS4702K607 0RK8204H609 0RD1002F609 0RD0751H609 0RD0751A609 0RD2001F609 0RD2200F609 0RD2200F609 0RD2200F609 0RD2200F609 0RD...

Страница 27: ... OWNERS NON LG AR EN REMOTE CONTROLLER W TXT GS REMOTE CONTROLLER W O TXT REMOTE CONTROLLER W O TXT LG REMOTE CONTROLLER W O TXT LG LGEIN REMOTE CONTROLLER W TXT LG ANTENNA 2 POLE 3 SECTION 700MM 650MM SOCKET CPT PCS030A 8PIN 14 360 SOCKET CPT PCS031A 7PIN THERMISTOR PTC J502P84D140M290Q TUNER DT5 BF70D PARTSNIC MULTI FS W TUNER TAEM G001D LG PAL TUNER TUMLF4EG 775F2 VARISTOR TVR621D14A 620V 10 U ...

Страница 28: ...P NO 3854VA0083A S 2002 11 14 ...

Страница 29: ...PRINTED CIRCUIT BOARD ...

Страница 30: ...54 B1 L255 C1 L260 C1 L401 F4 L402 F4 L501 C5 L502 D4 L503 D4 L506 D4 L551 D3 L552 D3 L553 D4 L601 D2 L611 D3 L621 D3 L631 D2 L661 B2 L662 D3 L663 C2 L801 E4 L802 E3 LD01 F1 P102 B5 P302 E5 P541 C3 P601 B2 P602 B2 P701 B2 P901 A2 P902 B1 P903 B2 P01A A4 P02A D1 P03A D1 P05A C1 P06A B2 P301A F4 P301B F4 P301C F4 P301D G4 P801A G1 P801B G1 P802A F1 P802B F1 PA01 F1 PJ201 C5 PJ202 C1 Q01 E1 Q11 B5 Q1...

Страница 31: ...SVC SHEET 3854V A0083A S SVC SHE ...

Страница 32: ...Dec 2003 Printed in Korea P NO 3828VD0107N ...

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