LG S90QY Service Manual page 36

WIRING DIAGRAM ............................................................................................................................................ 3-2
BLOCK DIAGRAM ............................................................................................................................................ 3-3
ONE POINT REPAIR GUIDE ............................................................................................................................ 3-4
1. NO BOOTING WHEN YOU TURN THE UNIT ON, NO MESSAGE OR "HELLO" ON FRONT PANEL..... 3-4
2. NO SOUND ............................................................................................................................................. 3-7
3. PROTECTION ERROR ......................................................................................................................... 3-11
WAVEFORMS OF MAJOR CHECK POINT .................................................................................................... 3-14
1. CRYSTAL .............................................................................................................................................. 3-14
2. REMOTE CONTROL ............................................................................................................................ 3-15
3. OPTICAL ............................................................................................................................................... 3-16
PRINTED CIRCUIT BOARD DIAGRAMS ....................................................................................................... 3-17
1. SMPS P. C. BOARD DIAGRAM ........................................................................................................... 3-17
2. MAIN P. C. BOARD DIAGRAM ............................................................................................................ 3-21
3. AMP P. C. BOARD DIAGRAM ............................................................................................................. 3-25
4. FRONT P. C. BOARD DIAGRAM ......................................................................................................... 3-29
5. TOUCH P. C. BOARD DIAGRAM ........................................................................................................ 3-29
SECTION 3
ELECTRICAL
CONTENTS
3-1
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