LG RH188S Service Manual page 71

Recognition Fail Case 2 :
DVD Disc
Check Pick-up Read Power
was 1.1~1.3mW.
YES
Is there RF signal at LIC121
Pin81?
YES
Is there
RF signal at LIC121 Pin95(RFP)
and Pin96 (RFN)?
YES
Check again after the replace
LIC121 It is OK?
YES
OK
Recognition Fail Case 3 :
Blank DVD+R/RW
Is there WBL
(LIC121 pin63) Signal?
NO
Replace LIC121.
NO
Go to 'LD CHECK'.
NO
Replace the Pickup.
NO
Replace the LIC121.
NO
Replace the LIC201.
YES
Is there WBL
(LIC201 pin39) Signal?
Check the connection
between LIC121 and LIC201.
4-10
YES
NO
Replace LIC201.