LG RF-20CC20M 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?
No
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 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
OK
Abnormal
NO
Check the waveform
at pin 44 of IC01
Open
Check
FUSE of AC line OK
NO
Check the waveform
Check /replace
OK
at pin 15,18 of IC631
Fuse,DB801
Check the voltage
OK
of C806
0V
NO
Check the waveform
Check/Replace
254~380V at pin 4,12 of IC602
Check /replace IC602
DB801
OK
Check the voltage
pin3 of IC803
NO
Check the voltage Check/Replace
Q621,IC603
at pin 6,7 of IC602
OK
Check /replace
IC801,IC803,IC804 Check the waveform
at pin 1,2,14,15 of IC602
OK
NO
Check the voltage Check/Replace
at pin 3,13 of IC602
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 OK
Check/Replace
Check
CPT Board
FR404,FR902,P302
Components
Check
Check
IC01,ZD901
FBT T401
IC901,P902,P541
COMPONENT LOCATION GUIDE
C01.........B4 C404 ......G4
C612.......B3 C814 ......D1 D904.......B2 P541.......C3 R09.........B4
C02.........B4 C405 ......G4 C621.......A2 C815.......E3 DB801....G2 P601.......B2 R10.........B4
C03.........B3 C406 ......G4 C622.......A3 C816.......E3 HIC01.....D3 P602.......B2 R11.........B4
C04.........B4 C441 ......G3 C623.......A3 C817.......E3 IC01........B4 P603.......B2
R12.........B4
C05.........B4 C442.......E5 C624.......B2 C818 ......D3 IC02........B3 P701.......B2 R13.........B4
C06 ........C4 C443.......E5 C625.......A2 C819.......E4 IC03........B4 P901.......A2 R14.........B5
C07.........B3 C444 ......G5 C626.......A2 C820.......E3 IC130......A4 P902.......B1 R15.........B5
C09 ........C4 C446.......E5 C631 ......D1 C821.......E2 IC301......E4 P903.......B2 R16.........B4
C10.........B3 C447.......E5 C632 ......D2 C822.......E3 IC591 .....C3 P01A ......A4 R17.........B4
C11.........B4 C449.......F5 C633 ......D1 C823 ......G3 IC601 .....D1 P02A ......D1 R18.........B5
C16.........F1 C450 ......G5 C634 ......C1
C824 ......D1 IC602......A3 P03A ......D1 R19.........B4
C21.........E1 C452 ......G3 C635 ......D1 C825 ......G3 IC603......B3 P05A ......C1 R20.........A4
C51.........B4 C453.......E4 C636 ......C1 C826 ......D1 IC621......A3 P06A ......B2 R21.........E1
C101.......A5 C457 ......G5 C637 ......C1 C828 ......D2 IC631 .....D1 P07A ......D1 R22.........E1
C102.......A5 C501 ......C4 C638 ......C1 C829 ......G2 IC661 .....C2 P301A.....F4 R23.........E1
C103.......B5 C502.......B5 C639 ......C2 C830.......E2 IC662 .....C2 P301B.....F4 R25.........E1
C104.......B5 C503 ......C5 C640 ......C2 C831.......E3 IC801......F3 P301C ....F4 R26 ........D1
C105.......B5
C504 ......C4 C641 ......C2 C832.......F3 IC802......F3 P301D....G4 R27 ........D1
C106.......A5 C505 ......C4 C642 ......D2 C833.......F4 IC803 .....G2 P801A ....G1 R28.........B5
C107.......A5 C506 ......C5 C643 ......D2 C834.......F4 IC804......F3 P801B ....G1 R29 ........D1
C108.......A5 C507 ......C5 C644 ......D1 C835 ......D1 IC842 .....D2
P802A.....F1 R30.........B5
C109.......A4 C508 ......C3 C645 ......D2 C839.......E3 IC844......E3 P802B.....F1 R31.........B5
C110.......B5 C509 ......C4 C646 ......D1 C841 ......D3 IC901......A1 P803A.....F1 R41.........A4
C111.......B5 C510 ......C4 C650.......A3 C901.......B1 L01 .........E1 P803B.....F1 R51.........B4
C112.......B5 C511 ......C5 C653 ......D2 C902.......A1 L04 .........B4 PA01.......F1 R52.........B4
C113.......A4 C512 ......D4 C654 ......D3 C903.......A2 L05 .........B3 PJ201.....C5 R101.......B5
C114.......A4 C513 ......D4 C655 ......C1 C904.......B2 L10 .........B3 PJ202.....C1 R102.......B5
C121.......A4 C514 ......C4
C661 ......C3 C905.......A1 L102 .......B5 Q01 ........E1 R103.......B5
C123.......A4 C515 ......C5 C662 ......C3 C906.......B1 L201 .......C5 Q11 ........B5 R105.......B5
C131.......A4 C516 ......C5 C663 ......C3 CC501....C4 L202 .......B5 Q101 ......B5 R106.......B5
C132.......A4 C517 ......C4 C664 ......C3 CC502....C4 L203 .......C5 Q102 ......B5
R107.......A5
C133.......A4 C518 ......D4 C665 ......D3 CC503....C4 L204 .......D5 Q103 ......C5 R108.......B4
C201 ......C5 C519 ......C4 C666 ......D2 CC504....C4 L205 .......D5 Q123 ......A4 R109.......B5
C202.......B5 C524 ......D4 C667 ......D3 CC505....C4 L210 .......E5 Q211 ......D4 R110.......B5
C203 ......C5 C529 ......D4 C668 ......D3 CC506....C4 L220 .......E5 Q212 ......D4 R111.......B5
C204.......B5 C530 ......C4 C669 ......D3 CC507....C4 L230 .......E5 Q213 ......E5 R112.......B5
C205 ......C5 C531 ......C4 C670 ......D2 CC508....C4 L251 .......C1 Q214 ......D5 R113.......B5
C206 ......D5 C532.......B2 C671 ......D2 D101.......B5
L252 .......C1 Q215 ......E4 R114.......B5
C207 ......D5 C533 ......C3 C672 ......D2 D102 ......C5 L253 .......B1 Q216 ......E5 R115 ......C5
C208 ......D5 C534 ......C4 C673 ......D2 D301.......E4 L254 .......B1 Q301 ......E4 R116 ......C5
C209 ......D5 C535 ......C4 C674 ......D2 D302.......E4 L255 .......C1 Q402 ......G4 R117 ......C5
C210.......E5 C536 ......C4 C675 ......C2 D401 ......G4 L260 .......C1 Q442 ......G3 R118 ......C5
C211 ......D5 C538 ......C3 C676 ......D2 D403.......F4 L401 .......F4 Q443 ......G5 R121.......A4
C212 ......D5 C540 ......C4 C677 ......D2 D441 ......G4 L402 .......F4 Q551 ......C3 R122.......A4
C213 ......D4
C541 ......C4 C678 ......C2 D442.......E5 L501 .......C5 Q552 ......D4 R123.......A5
C221 ......D5 C542 ......C4 C679 ......C2 D443.......E5 L502 .......D4 Q553 ......D3 R124.......A5
C222 ......D5 C543 ......C3 C680 ......C2 D444 ......G5 L503 .......D4 Q554 ......D3 R132.......A4
C223 ......D5 C544 ......C3 C681 ......C2 D501.......B3 L506 .......D4
Q555 ......C3 R133.......A4
C224.......E5 C545 ......C3 C682 ......C2 D571.......F5 L551 .......D3 Q571 ......E5 R134.......A4
C251 ......D1 C546 ......C3 C683 ......C2 D602.......B3 L552 .......D3 Q621 ......A3 R201 ......C5
C253 ......C1 C548 ......D4 C684 ......C2 D621.......A3 L553 .......D4 Q651 ......D5 R204 ......C5
C255 ......C1 C549 ......C4 C685 ......C2 D801.......E2 L601 .......D2 Q652 ......D5 R205 ......C5
C256.......B1 C551 ......D4 C686 ......C2 D802.......F3 L611 .......D3 Q653 ......D4 R206 ......C5
C257.......B1 C552 ......D4 C687 ......C2 D803.......F3 L620 .......A3 Q671 ......D3 R207 ......C5
C258 ......C1 C553 ......D3
C688 ......C2 D804.......E2 L621 .......D3 Q672 ......D3 R208.......E5
C259 ......C1 C561 ......C4 C689 ......C2 D805.......E2 L631 .......D2 Q801 ......E4 R212 ......D5
C260 ......C1 C573.......E5 C690 ......C2 D806.......F2 L661 .......B2 Q802 ......E4 R213 ......D5
C261 ......C1 C574.......E5 C801.......F2 D807.......E4 L662 .......D3 Q803 ......E2
R214.......E5
C262 ......C1 C593 ......C3 C802.......F2 D808.......E3 L663 .......C2 Q804.......F4 R215.......E5
C301.......F4 C594 ......C4 C803 ......G2 D809 ......D1 L801 .......E4 Q805 ......E4 R216 ......D5
C302.......E4 C595 ......C1 C804.......F3 D810.......E1 L802 .......E3 Q806 ......E4 R217 ......D5
C303.......E4 C601.......B3 C805.......F2 D811 ......D1 L901 .......B1 R01.........B4 R218 ......D5
C304.......E4 C602.......B2 C806.......F2 D812.......E1 L902 .......B1 R02.........B4 R219 ......D5
C305.......E4 C603.......B2 C807.......F2 D813 ......D2 LD01.......F1 R03.........B4 R220 ......D5
C306.......E4 C604.......B3 C808 ......G2 D814.......E2
P102.......B5 R04.........B4 R221 ......D5
C307.......F4 C605.......B2 C809 ......G1 D816.......E2 P103.......A5 R05.........B4 R222 ......D5
C401 ......G4 C606.......A2 C811 ......G3 D901.......A1 P104.......A4 R06.........B3 R223 ......D5
C402.......F3 C607.......B3 C812.......E2 D902.......A1 P302.......E5 R07.........B3 R224 ......D5
C403 ......G4 C611.......B3 C813 ......D2 D903.......A1 P501.......C3 R08.........B4 R225 ......D5
NO PICTURE / NO SONUD
Is any OSD displayed?
No
OK
OK
Check IC01 pin50,51,52,53
Check receiving system in MENU
(IK,R,G,B)
& excute Auto-program.
Check / Replace
NO
IC01
Check/ Replace Does the Auto-program
operate properly.
IC01
NO
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
IIC Bus Line
OK
NO Is the CVBS signal OK.
Check / Replace
( IC01 pin40 )
IC01,TUNER
OK
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)
OK
Check / Replace
CPT Board component
F811,D824
WIRING DIAGRAM
" B "
POINT
CPT PWB
SPK(R)
4 P902
Not OK
1
" C "
" A "
POINT
Check the
Heater pulse of FBT
P802
P801
T401
P602 P601
SPK(R) SPK(L)
1
P301
Not OK P541
P01A
MAIN PWB
JW2 P302
Check
FBT T401
1. CONNECTOR LEAD
"A" POINT : P541, P301, P302, CPT EARTH,
JW1, FOCUS & SCREEN LEAD
TWISTER HOLDER
"B" POINT : TWISTER HOLDER
"C" POINT : D-COIL HOLDER SPEAKER(L)
LEAD
"D" POINT : SPEAKER(L) LEAD & D-COIL
P802 D-COIL HOLDER 1
,JW2
SIDE A/V
R226.......E5 R601.......B3 R908.......A1
R227 ......D5 R602.......B3 R909.......A1
R228 ......D5 R603.......B3 R910.......A1
R251 ......C1 R604.......B2 R911.......A2
R254.......B2 R606.......B2 R912.......B1
R255.......B2 R608.......B2 RC801 ....F2
R301.......E4 R609.......B2
RL801.....E2
R302.......E4 R610 ......C3 SG901 ....A1
R304.......E4 R611 ......C3 SG902 ....A1
R305.......E4 R621.......A3 SG903 ....A2
R306.......F4 R622.......A3 SG904 ....A2
R307.......E4 R623.......A3 SW01 .....D1
R308.......E4 R624.......A3 SW02 .....D1
R310 ......D4 R625.......A3 SW03 .....D1
R311.......E4 R626.......A3 SW04 .....D1
R312.......E4 R627.......A3 SW05 .....E1
R313.......E4 R628.......A2 SW06 .....E1
R401.......F4 R631 ......C1 SW801 ...G1
R402.......F4 R632 ......C2 T101 .......B4
R442 ......G3 R633 ......C2 T401 .......F5
R443.......F3 R634 ......C2 T402.......G4
R444 ......G4 R651 ......D5 T551.......D3
R446.......F5 R652 ......D4 T552.......D3
R447.......E5
R653.......E5 T553.......D3
R448 ......G5 R654 ......D5 T801 .......F1
R449 ......G5 R655 ......D5 T802 .......F3
R450.......E5 R656 ......D5 T803 .......E1
R451.......F3 R657 ......D4 TH801 ....E1
R453.......F5 R660 ......D2 TH802.....F2
R454 ......G3 R662.......B2 TU101 ....B5
R455.......E5 R663.......B2 VD801....G1
R456.......F5 R664 ......C3 X01.........B4
R501 ......C5 R665 ......D3 X661.......C2
R502 ......D3 R666 ......D3
Z102.......C5
R503 ......C3 R667 ......D2 Z551.......D4
R504 ......C4 R668 ......D2 ZD01 ......A4
R505 ......C5 R669 ......D2 ZD101 ....A5
R506 ......D5 R670 ......C2 ZD121 ....C3
R518 ......D4 R671 ......C2 ZD122 ....C3
R521 ......D4 R672 ......C3 ZD203 ....C5
R522 ......D4 R801.......F3 ZD205 ....C5
R523 ......D4 R802.......F3 ZD206 ....D5
R524 ......D4 R803 ......G2 ZD207 ....D5
R525 ......D4 R804 ......G3 ZD253 ....C1
R526 ......C4 R805 ......G2 ZD255 ....C1
R537 ......C3 R806.......F3 ZD441.....F4
R538 ......C3 R807 ......D2 ZD442 ....E5
R539 ......C3 R808.......E4 ZD443 ....E4
R540 ......C3 R809 ......G2 ZD447 ....G5
R541 ......C3 R810.......E2 ZD501 ....C3
R542 ......C3
R811 ......D1 ZD502 ....C3
R544 ......D4 R812 ......G3 ZD503 ....C3
R545 ......C3 R813.......E3 ZD504 ....C3
R546 ......C3 R814.......E3 ZD505 ....B4
R547 ......C3 R815.......F3 ZD534 ....D4
R548 ......C3 R816.......F3 ZD601 ....B3
R551 ......C4 R819.......F4 ZD634 ....D1
R552 ......C4 R820.......F4 ZD669 ....D2
R553 ......C4 R822.......F4 ZD801 ....E4
R554 ......D4 R823.......E4 ZD901 ....B1
R555 ......D4 R824.......E4
ZD902 ....B1
R556 ......D4 R888.......F1 ZD903 ....B1
R557 ......D3 R901.......B1 ZD904 ....B1
R558 ......C4 R902.......B1
R559 ......C3 R903.......B1
R560 ......D4 R904.......B1
R561 ......D4 R905.......B1
NO SOUND / PICTURE OK
R572.......E5 R906.......A1
R573.......E5 R907.......A1
MONO
Select correct system
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
Check the waveform NO
Check/Replace IC601
at pin 4 of IC601
OK
Go to
NO
Check/Replace
Check the voltage
NO SOUND /
FR803,D804
at pin 5 of IC601
PICTURE OK
RF STEREO
Select correct system
in menu
OK
Check the waveform NO Check / Replace
at pin 16 of TU101 TU101
OK
Check the waveform NO
Check the voltage
at pin 24,25 of IC661 at pin 16,33,46 of IC661
SPK(L)
3 OK
Check the waveform NO
Check/Replace
at pin 4,12 of IC602 Q671,Q672
" D "
POINT
OK
NO Check/Replace
Check the voltage
Q621,IC603
at pin 6,7 of IC602
OK
Check the waveform
at pin 1,2,14,15 of IC602
OK
NO
Check the voltage
Check/Replace
at pin 3,13 of IC602 F811,D824
NO Check the waveform
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