Laser Operating Is Abnormal - LG HB954TB Service Manual

ELECTRICAL TROUBLESHOOTING GUIDE

7. LASER OPERATING IS ABNORMAL

Laser operating is abnormal
Does
laser turn on?
NO
Is there
LDD vcc voltage input?
(LIC201 Pin32, 33)
YES
Check the LDD data signals.
(LCN700 Pin39,40,41,42)
OK
Check the connector
LCN700 and Pick-up FFC
cable connection
OK
Replace the traverse
assembly. (Pick-up)
YES
Replace the traverse assembly
and scan the Pick-up barcode.
Check the main PCB Pick-up
interface circuit
Pin32 : Check the 5V path.
NO
Pin33 : Check the 8.1V path
and LIC902 operation
Is there
NG
LDD data signal
communication? (LIC501
Pin44,45,46,
90)
Replace the LIC501.
4-8
NG
YES
Check the signal pattern and
application components
NO