LG CF-14F80K Service Manual page 26

PRINTED CIRCUIT BOARD
MAIN & CPT
TROUBLESHOOTING
NO RASTER
CHECK +B
at D807 cathode
Normal
Is the voltage at pin61,56
& 54 of IC01 3.3V?
Yes
No
Is the voltage at pin14
Is the voltage at pin3
& 39 of IC01 8V?
of IC02 5V?
Yes
No
Yes
Check the in/out
Check / Replace Check the In/Out of IC844
Check pin33
IC01,IC02 of IC842
No
of IC01(H-out)
No
Check &replace
Check the voltage IC01 Yes
Check IC01
at D805 or D815
Check Q402 pin1 high?
cathode
collector waveform
No
No
Check &replace
Check / Replace
Yes
Q402
F812
Check T402
& each pin voltage
No
Check &replace
Yes
T402
Check &replace
T402
AV STEREO
Select correct system
in menu
Abnormal
OK
Check the waveform NO
Open
Check
at pin 44 of IC01
FUSE of AC line
OK
Check /replace
OK
Fuse,DB801 Check the waveform NO
at pin 15,18 of IC631
Check the voltage
of C806
No
0V
OK
254~380V
Check /replace
NO
Check the waveform
DB801
at pin 4,12 of IC602
Check the voltage
pin3 of IC803
No
OK
NO
Check the voltage
at pin 6,7 of IC602
Check /replace
OK
IC801,IC803,IC804
Check the waveform
at pin 1,2,14,15 of IC602
OK
NO
Check the voltage
at pin 3,13 of IC602
COMPONENT LOCATION GUIDE
C01.........B4 C403 ......G4 C607.......B3 C811 ......G3 F812 .......E2 L801 .......E4 R05.........B4 R218 ......D5
C02.........B4 C404 ......G4 C611.......B3 C812.......E2 F801A ....G2 L802 .......E3 R06.........B3 R219 ......D5
C03.........B3 C405 ......G4 C612.......B3 C813 ......D2 F801B ....G1 LD01.......F1 R07.........B3 R220 ......D5
C04.........B4 C441 ......G3 C621.......A2 C814 ......D1 FB801.....F2 P102.......B5 R08.........B4 R221 ......D5
C05.........B4 C442.......E5 C622.......A3 C815.......E3 FB802.....F2 P302.......E5 R09.........B4 R222 ......D5
C06 ........C4 C443.......E5 C623.......A3 C816.......E3 FB803.....E3 P541.......C3 R10.........B4 R223 ......D5
C07.........B3 C444 ......G5 C624.......B2 C817.......E3 FR441 ....E5 P601.......B2 R11.........B4 R224 ......D5
C09 ........C4 C445.......E5 C625.......A2 C818 ......D3 FR442 ....E5 P602.......B2 R12.........B4 R225 ......D5
C10.........B3 C446.......E5 C626.......A2 C819.......E4 FR443 ....E5 P701.......B2 R13.........B4 R226.......E5
C11.........B4 C449.......F5 C631 ......D1 C820.......E3 FR802 ....E3 P901.......A2 R14.........B5 R227 ......D5
C16.........F1 C450 ......G5 C632 ......D2 C821.......E2 FR803 ....E2 P902.......B1 R15.........B5 R228 ......D5
C21.........E1 C452 ......G3 C633 ......D1 C822.......E3 FR901 ....B1 P903.......B2 R16.........B4 R251 ......C1
C51.........B4 C453.......E4 C634 ......C1 C823 ......G3 HIC01.....D3 P01A ......A4 R17.........B4 R254.......B2
C101.......A5 C457 ......G5 C635 ......D1 C824 ......D1 IC01........B4 P02A ......D1 R18.........B5 R255.......B2
C102.......A5 C501 ......C4 C636 ......C1 C825 ......G3 IC02........B3 P03A ......D1 R19.........B4 R301.......E4
C103.......B5 C502.......B5 C637 ......C1 C826 ......D1 IC03........B4 P05A ......C1 R20.........A4 R302.......E4
C104.......B5 C503 ......C5 C638 ......C1 C828 ......D2 IC130......A4 P06A ......B2 R21.........E1 R304.......E4
C105.......B5 C504 ......C4 C639 ......C2 C829 ......G2 IC301......E4 P301A.....F4 R22.........E1 R305.......E4
C106.......A5 C505 ......C4 C640 ......C2 C830.......E2 IC591 .....C3 P301B.....F4 R23.........E1 R306.......F4
C107.......A5 C506 ......C5 C641 ......C2 C831.......E3 IC601 .....D1 P301C ....F4 R25.........E1 R307.......E4
C108.......A5 C507 ......C5 C642 ......D2 C832.......F3 IC602......A3 P301D....G4 R26 ........D1 R308.......E4
C109.......A4 C508 ......C3 C643 ......D2 C833.......F4 IC603......B3 P801A ....G1 R27 ........D1 R310 ......D4
C110.......B5 C509 ......C4 C644 ......D1 C834.......F4 IC621......A3 P801B ....G1 R28.........B5 R311.......E4
C111.......B5 C510 ......C4 C645 ......D2 C835 ......D1 IC631 .....D1 P802A.....F1 R29 ........D1 R312.......E4
C112.......B5 C511 ......C5 C646 ......D1 C841 ......D3 IC661 .....C2 P802B.....F1 R30.........B5 R313.......E4
C113.......A4 C512 ......D4 C653 ......D2 C901.......B1 IC662 .....C2 PA01.......F1 R31.........B5 R401.......F4
C114.......A4 C513 ......D4 C654 ......D3 C902.......A1 IC801......F3 PJ201.....C5 R32.........E1 R402.......F4
C121.......A4 C514 ......C4 C655 ......C1 C903.......A2 IC802......F3 PJ202.....C1 R41.........A4 R442 ......G3
C123.......A4 C515 ......C5 C661 ......C3 C904.......B2 IC803 .....G2 Q01 ........E1 R51.........B4 R443.......F3
C131.......A4 C516 ......C5 C662 ......C3 C905.......A1 IC804......F3 Q11 ........B5 R52.........B4 R444 ......G4
C132.......A4 C517 ......C4 C663 ......C3 C906.......B1 IC842 .....D2 Q101 ......B5 R101.......B5 R446.......F5
C201 ......C5 C518 ......D4 C664 ......C3 D101.......B5 IC844......E3 Q102 ......B5 R102.......B5 R447.......E5
C202.......B5 C519 ......C4 C665 ......D3 D102 ......C5 IC901......A1 Q103 ......C5 R103.......B5 R448 ......G5
C203 ......C5 C524 ......D4 C666 ......D2 D301.......E4 L01 .........E1 Q123 ......A4 R105.......B5 R450.......E5
C204.......B5 C529 ......D4 C667 ......D3 D302.......E4 L04 .........B4 Q211 ......D4 R106.......B5 R451.......F3
C205 ......C5 C530 ......C4 C668 ......D3 D401 ......G4 L05 .........B3 Q212 ......D4 R107.......A5 R453.......F5
C206 ......D5 C531 ......C4 C669 ......D3 D403.......F4 L10 .........B3 Q213 ......E5 R108.......B5 R454 ......G3
C207 ......D5 C532.......B2 C670 ......D2 D441 ......G4 L102 .......B5 Q214 ......D5 R109.......B5 R455.......E5
C208 ......D5 C534 ......C4 C671 ......D2 D442.......E5 L201 .......C5 Q215 ......E4 R110.......B5 R456.......F5
C209 ......D5 C535 ......C4 C672 ......D2 D443.......E5 L202 .......B5 Q216 ......E5 R111.......B5 R501 ......C5
C210.......E5 C536 ......C4 C673 ......D2 D444 ......G5 L203 .......C5 Q301 ......E4 R112.......B5 R502 ......D3
C211 ......D5 C538 ......C3 C674 ......D2 D501.......B3 L204 .......D5 Q402 ......G4 R113.......B5 R503 ......C3
C212 ......D5 C540 ......C4 C675 ......C2 D571.......F5 L205 .......D5 Q442 ......G3 R114.......B5 R504 ......C4
C221 ......D5 C541 ......C4 C676 ......D2 D602.......B3 L210 .......E5 Q443 ......G5 R115 ......C5 R505 ......C5
C222 ......D5 C542 ......C4 C677 ......D2 D621.......A3 L251 .......C1 Q551 ......C3 R116 ......C5 R506 ......D5
C223 ......D5 C543 ......C3 C678 ......C2 D801.......E2 L252 .......C1 Q552 ......D4 R117 ......C5 R518 ......D4
C224.......E5 C544 ......C3 C679 ......C2 D802.......F3 L253 .......B1 Q553 ......D3 R118 ......C5 R521 ......D4
C251 ......D1 C545 ......C3 C680 ......C2 D803.......F3 L254 .......B1 Q554 ......D3 R121.......A4 R522 ......D4
C253 ......C1 C546 ......C3 C681 ......C2 D804.......E2 L255 .......C1 Q555 ......C3 R122.......A4 R523 ......D4
C255 ......C1 C548 ......D4 C682 ......C2 D805.......E2 L260 .......C1 Q571 ......E5 R123.......A5 R524 ......D4
C256.......B1 C549 ......C4 C683 ......C2 D806.......F2 L401 .......F4 Q621 ......A3 R124.......A5 R525 ......D4
C257.......B1 C551 ......D4 C684 ......C2 D807.......E4 L402 .......F4 Q651 ......D5 R132.......A4 R526 ......C4
C258 ......C1 C552 ......D4 C685 ......C2 D808.......E3 L501 .......C5 Q652 ......D5 R133.......A4 R537 ......C3
C259 ......C1 C553 ......D3 C686 ......C2 D809 ......D1 L502 .......D4 Q653 ......D4 R134.......A4 R538 ......C3
C260 ......C1 C561 ......C4 C687 ......C2 D810.......E1 L503 .......D4 Q671 ......D3 R201 ......C5 R539 ......C3
C261 ......C1 C573.......E5 C688 ......C2 D811 ......D1 L506 .......D4 Q672 ......D3 R204 ......C5 R540 ......C3
C262 ......C1 C574.......E5 C689 ......C2 D812.......E1 L551 .......D3 Q801 ......E4 R205 ......C5 R541 ......C3
C301.......F4 C593 ......C3 C690 ......C2 D813 ......D2 L552 .......D3 Q802 ......E4 R206 ......C5 R542 ......C3
C302.......E4 C594 ......C4 C801.......F2 D814.......E2 L553 .......D4 Q803 ......E2 R207 ......C5 R544 ......D4
C303.......E4 C595 ......C1 C802.......F2 D901.......A1 L601 .......D2 Q804.......F4 R208.......E5 R545 ......C3
C304.......E4 C601.......B3 C803 ......G2 D902.......A1 L611 .......D3 Q805 ......E4 R212 ......D5 R546 ......C3
C305.......E4 C602.......B2 C804.......F3 D903.......A1 L621 .......D3 Q806 ......E4 R213 ......D5 R547 ......C3
C306.......E4 C603.......B2 C806.......F2 D904.......B2 L631 .......D2 R01.........B4 R214.......E5 R548 ......C3
C307.......F4 C604.......B3 C807.......F2 DB801....G2 L661 .......B2 R02.........B4 R215.......E5 R551 ......C4
C401 ......G4 C605.......B2 C808 ......G2 F802.......G2 L662 .......D3 R03.........B4 R216 ......D5 R552 ......C4
C402.......F3 C606.......A2 C809 ......G1 F811 .......E2 L663 .......C2 R04.........B4 R217 ......D5 R553 ......C4
NO PICTURE / NO SONUD
Is any OSD displayed?
No
OK Check IC01 pin50,51,52,53
Check receiving system in MENU
(IK,R,G,B)
& excute Auto-program.
Check / Replace
NO
IC01
Does the Auto-program
Check/ Replace
IC01 operate properly.
Check the voltage
Store in manual-program MENU
at pin 6 of IC631
Check NO Check 5V, 33V & IIC Bus Line
5V, 33V & of TUNER
Check/Replace
IIC Bus Line
IC602
NO
Is the CVBS signal OK.
Check / Replace
( IC01 pin40 )
IC01,TUNER
Check/Replace
Q621,IC603
OK NO
Check Check IK Check R,G,B signal
CVBS singal Line
signal at IC01 pin50 at IC501 pin51,52,53
& IC01
(similar to CVBS)
Check / Replace
CPT Board component
Check/Replace
F811,D824
NO RASTER / SOUND OK
Check the
Heater voltage of CPT
(6 ~ 6.5Vrms)
OK
Check Check
HV, Screen voltage of Ik Current of
CPT IC01,pin50
Not OK OK Not OK
Check/Replace
CPT Board
FR404,FR902,P302
Components
Check
Check
IC01,ZD901
FBT T401
IC901,P902,P541
WIRING DIAGRAM
R554 ......D4 R820.......F4
R555 ......D4 R822.......F4
R556 ......D4 R823.......E4
R557 ......D3 R824.......E4
R558 ......C4 R901.......B1
R559 ......C3 R902.......B1
R560 ......D4 R903.......B1
R561 ......D4 R904.......B1
R572.......E5 R905.......B1
R573.......E5 R906.......A1
R601.......B3 R907.......A1
R602.......B3 R908.......A1
R603.......B3 R909.......A1
CPT PWB
R604.......B2 R910.......A1
R606.......B2 R911.......A2
SPK(R)
R608.......B2 R912.......B1
4 P902
R609.......B2 RC801 ....F2
R610 ......C3 RL801.....E2
R611 ......C3 SG901 ....A1
1
R621.......A3 SG902 ....A1
R622.......A3 SG903 ....A2 " C "
R623.......A3 SG904 ....A2
R624.......A3 SW01 .....D1
" A "
R625.......A3 SW02 .....D1
POINT
R626.......A3 SW03 .....D1
R627.......A3 SW04 .....D1
R628.......A2 SW05 .....E1
R631 ......C1 SW06 .....E1 P802
R632 ......C2 SW801 ...G1
R633 ......C2 T101 .......B5
P602 P601
SPK(R) SPK(L)
R634 ......C2 T401 .......F5
R651 ......D5 T402.......G4 1
P541
R652 ......D4 T551.......D3
P01A
R653.......E5 T552.......D3
R654 ......D5 T553.......D3
MAIN PWB
R655 ......D5 T801 .......F1
JW2
R656 ......D5 T802 .......F3
R657 ......D4 T803 .......E1
R662.......B2 TH801 ....E1
R663.......B2 TH802.....F2
R664 ......C3 TU101 ....B5
R665 ......D3 VD801....G1
1. CONNECTOR LEAD
R666 ......D3 X01.........B4
R667 ......D2 X661.......C2
"A" POINT : P541, P301, P302, CPT EARTH,
R668 ......D2 Z102.......C5
JW1, FOCUS & SCREEN LEAD
R669 ......D2 Z551.......D4 TWISTER HOLDER
R670 ......C2 ZD01 ......A4
"B" POINT : TWISTER HOLDER
R671 ......C2 ZD101 ....A5
"C" POINT : D-COIL HOLDER SPEAKER(L)
R672 ......C3 ZD441.....F4
LEAD
R801.......F3 ZD442 ....E5
R802.......F3 ZD443 ....E4
"D" POINT : SPEAKER(L) LEAD & D-COIL
R803 ......G2 ZD447 ....G5
P802 D-COIL HOLDER 1
R804 ......G3 ZD501 ....C3
,JW2
R805 ......G2 ZD601 ....B3
R806.......F3 ZD801 ....E4
R807 ......D2 ZD901 ....B1
R808.......E4 ZD902 ....B1
NO SOUND / PICTURE OK
R809 ......G2 ZD903 ....B1
R810.......E2 ZD904 ....B1
R811 ......D1
R812 ......G3
MONO
R813.......E3
R814.......E3
R815.......F3
Select correct system
R816.......F3
R819.......F4 in menu
OK
Check the waveform Check the waveform
NO
at pin 44 of IC01 at pin 35 of IC501
OK
OK
Check the waveform NO
Check/Replace Q621
at pin 1 of IC601
OK
OK
NO
Check the waveform
Check/Replace IC601
at pin 4 of IC601
NO
OK
NO Check/Replace
Check the voltage
FR803,D804
at pin 5 of IC601
OK
Go to
NO SOUND /
PICTURE OK
OK RF STEREO
Select correct system
in menu
OK
OK
NO
Check the waveform Check / Replace
at pin 16 of TU101 TU101
OK
NO
Check the waveform Check the voltage
at pin 24,25 of IC661 at pin 16,33,46 of IC661
OK
NO
Check the waveform
Check/Replace
Not OK
at pin 4,12 of IC602 Q671,Q672
OK
Check the
NO
Check/Replace
Heater pulse of FBT Check the voltage
Q621,IC603
T401 at pin 6,7 of IC602
OK Not OK
OK
Check the waveform
at pin 1,2,14,15 of IC602
Check Check
FBT T401
OK
NO
Check the voltage Check/Replace
at pin 3,13 of IC602 F811,D824
" B "
POINT
SPK(L)
3
" D "
POINT
P801
P301
P302
Check the waveform
NO
at pin 4 of IC651
NO
Check the waveform
at pin 2,7 of IC651
NO
Check the waveform
at pin28 IC01
NO
OK
Check/Replace
Check / Replace
IC01
IC651
NO Check the voltage
at pin1 of IC131
NO
Check/Replace
IC131,IC661