LG GCC-4241N Service Manual page 54

Recognition Fail Case1:
CD-ROM Fail.
LD Check.
OK
Does Focus Servo
operate normally?
OK
Does Tracking Servo
operate normally?
OK
Check
Pickup RF signal(TL320) was
200~800mVpp?
NG
1)Check Soldering of PG101.
2) Check voltage of TL331(5V).
3) Check voltage of TL327(2.2V).
4) Check insertion or damage of
Main FPC.
OK
Replace the P/U and execute LD
Power calibration.
Recognition Fail Case1:
Blank CD-R/RW Fail.
Is there WBL(TL117) signal?
NG
Replace IC101
56
NG
Go to "LD Control is abnormal".
NG
Go to "Focus Servo is unstable".
NG
Go to "Tracking Servo is
unstable".
OK
Is there
WBLI(IC201#116) signal?
OK
Replace IC201.