LG LPC-M155X Service Manual page 17

When laser does not light
Is IC1 pin90 voltage about 2.5V?
No
Has pick-up returned to the
innermost position?
Yes
Yes
Does pick-up stop after
naving moved to the
innermost position?
Has laser power source
returned to the Q5?
(Q5 collector voltage about
1.7V)
Yes
Flow laser current?
Both voltage of R33 is
about 1.0?
LGE Internal Use Only
No
Are data transferrd form IC1?
Yes
Does voltage appear at
IC2 17, 18?
Yes
Are input/output detected
at CON1 pin5?
Yes
OPEN
CLOSE
Yes
No
»
R33 1.0V
«
R33 1.0V
- 3-6 -
No
IC1 defective.
IC1, 2 Defective.
No
Slide motor defective.
Connector defective.
No
LMT SW defective.
Connector defective.
IC1 defective.
Connector defective .
Yes
Q5 defective.
laser defective
Yes
Defective laser and/or
connector.
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