LG LAB550H Service Manual page 60

ELECTRICAL TROUBLESHOOTING GUIDE
3A
"LG Logo"
Display on Monitor
OK?
YES
"LG Logo"
display on monitor
OK?
YES
System Part OK.
IC155: 1.5 V/
NO
IC153: 1.2 V/
IC157: 3.3 V OK?
X501
27.000 MHz
OK?
IC502 NF_ALE,
NF_CLE OK?
Replace IC501 MT8553.
3B
Display
NO
cable connection
OK?
2-47
NO
YES
NO
YES
NO
YES
YES
NO
Check IC155 / IC153 /
IC157 and SMPS board.
Replace X501.
Replace IC502
(NAND FLASH).
Proper display
cable connect.