Samsung SC-148B Service Manual page 20

No laser on
Open and close tray(Disc insettion)
Y
IC101 10pin changes from 0V to +3.3V?
Y
IC101 9pin changes from 4.2V to 3.6V?
Y
CN501 3pin changes from 2V to 2.5V?
Y
CN501 2pin changes from 0V to 0.7V?
Y
Replace pick-up
N
Refer to 'No tray open/close'
N
Refer to 'Check power source and initial state'
N
Check IC101 power input and replace.
N
Check D101, L101, Q102, R102, C103 soldering
N
Check Pick-up FPC connection state
21