LG MCV902 Service Manual page 57

1-6. READING OK CHECK #C (= "NO DISC" DISPLAY)
C
IS ?V APPLIED
TO PIN10 OF PN801
LASER SUPPLY
VOLTAGE CHECK
YES
CHECK PN801
CONNECTOR LINE
YES
DEFECTIVE PICKUP
LASER PART
IS 3.3V
APPLIED TO
PIN30, 36, 39, 41, 61,
NO
68, 75 OF IC801
RF IC SUPPLY
VOLTAGE
CHECK
IS 2.3V PIN18(LDO)
OF IC801
LASER CONTROL
VOLTAGE CHECK
DEFECTIVE Q801 OR D801
NO
DEFECTIVE PN801
CONNECTOR
4-6
NO
YES
NO
YES
DEFECTIVE IC804
DEFECTIVE IC801