LG RHT497H Service Manual page 16

ELECTRICAL TROUBLESHOOTING GUIDE
1. Power SuPPly on SMPS board ............3-2
2. Power SuPPly on i/o board ..................3-4
3. SySteM circuit Part .................................3-8
4. diSc not recoGniZed ................................3-8
5. when PlayinG diSc,
no audio outPut .........................................3-9
6. no oPtical/diGital outPut ...................3-10
7. no tuner audio outPut .........................3-11
8. no external audio inPut ......................3-12
9. no rGb / coMPonent video SiGnal
when Play diSc ..........................................3-13
10. no coMPoSite / S-video SiGnal
when Play diSc ..........................................3-14
11. no tv, external inPut
video SiGnal ...............................................3-15
12. no dv (ieee1394)
inPut (video/audio) SiGnal ....................3-16
13. no dvb_t audio / video outPut ...........3-17
WAVEFORMS
........................................................3-18
1. SySteM block .............................................3-18
2. video block (color bar inPut) ..........3-21
3. audio block (1khz Sinewave inPut) ...3-22
4. Serial interFace block
(between Main & i/o) .................................3-24
5. tuner block ...............................................3-25
6. hdMi block ...................................................3-26
WIRING DIAGRAMS
1. wirinG diaGraM 1 ......................................3-27
2. wirinG diaGraM 2 ......................................3-28
BLOCK DIAGRAMS
1. overall block diaGraM ........................3-30
2. SMPS board block diaGraM ................3-31
3. Main board block diaGraM .................3-32
SECTION 3
ELECTRICAL
CONTENTS
..........3-2
...........................................3-27
............................................3-30
4. Power Main board block diaGraM ..3-33
5. i/o board block diaGraM ......................3-34
6. video inPut block diaGraM .................3-35
7. video outPut block diaGraM .............3-36
8. audio inPut block diaGraM .................3-37
9. audio outPut block diaGraM .............3-38
10. Power i/o block diaGraM .....................3-39
11. Fld tiMer board block diaGraM .......3-40
12. Power tiMer and
ci block diaGraM ......................................3-41
CIRCUIT DIAGRAMS
1. SMPS circuit diaGraM ............................3-43
2. MPeG circuit diaGraM ............................3-45
3. FlaSh / ddr circuit diaGraM ...............3-47
4. ieee1394 circuit diaGraM ......................3-49
5. ataPi / hdMi / uSb circuit diaGraM ....3-51
6. i/o µ-coM circuit diaGraM .....................3-53
7. Scart / rca circuit diaGraM ...............3-55
8. tuner / decoder circuit diaGraM ....3-57
9. ldo circuit diaGraM ...............................3-59
10. coMMon interFace board
circuit diaGraM(oPtional) ...................3-61
11. hdMi dauGhter board
circuit diaGraM ........................................3-63
12. tiMer circuit diaGraM ...........................3-65
13. key circuit diaGraM ................................3-67
• cIrcuIt VoltaGe cHart
PRINTED CIRCUIT BOARD DIAGRAMS
1. Main P.c.board ...........................................3-77
2. i/o P.c.board................................................3-79
3. SMPS (Power) P.c.board ........................3-83
4. tiMer & key P.c.board ............................3-85
5. coMMon interFace P.c.board
(oPtional) .....................................................3-87
6. hdMi P.c.board ...........................................3-87
3-1
..........................................3-43
...................3-69
..3-77