LG S42S1-W Service Manual

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ELECTRICAL TROUBLESHOOTING GUIDE
3. POWER SUPPLY ON MAIN BOARD
No 3.3 V.
Check IC151 and replace.
Is the VCC 3.8 VA supplied to IC151 pin3?
Is there ‘H’ signal at IC153 pin2?
Check 3.8 VA on SMPS Board.
Check IC101 pin58 (DCDC33_CTRL).
NO
NO
YES
YES
YES
No 5 V.
Check IC153 and Replace.
Is the VCC 6 VA supplied to IC153 pin2?
Is there ‘H’ signal at IC153 pin1?
Check 6 VA on SMPS Board.
Check IC101 pin68 (LDO_CTRL).
NO
NO
YES
YES
YES
No 1.2 V.
Check IC155 and replace.
Is the VCC 14 VA supplied to IC155 pin2?
Is there 1.2V at IC155 pin8?
Check 14 VA on SMPS Board.
Check IC101 pin68 (LDO_CTRL).
NO
NO
YES
YES
YES
No 1.5 V.
Check IC150 and replace.
Is the VCC 14 VA supplied to IC150 pin13?
Is there 1.5 V at IC150 pin12?
Check 14 VA on SMPS Board
Check IC101 pin59 (DCDC15_CTRL).
NO
NO
YES
YES
YES

LG S42S1-W Specifications

General

Brand	LG
Model	S42S1-W
Category	Home Theater System
Language	English