LG FH6 - Page 40

3-21
ELECTRICAL TROUBLESHOOTING GUIDE
YES
YES
YES
YES
YES
YES
YES
No PVDD (50 VA / 40 VA)
Check IC501 (MLC3730S) IC on MAIN board.
Replace IC931.
Replace D981.
Replace C981, C982.
Power line of MAIN PCB is short.
Is Q901 normal?
Check or replace Q901.
Replace Q921.
NO
NO
NO
NO
NO
NO
Is the P-CTRL normal?
Is IC931 normal?
Is D981 normal?
Is C981, C982 normal?
Is the VCC
(18 V ~ 25 V) supplied to IC931
pin4?
Is Q921 normal?
SYSTEM POWER SUPPLY ON SMPS BOARD