LG FFH-185A Service Manual page 10

Fails to initial read
Disc motor turns.
YES
Does tracking
Does RF
NO
servo work?
waveform
Lower envelope
appear?
of Test Pin(RF)
Test Pin(RF)
waveform is flat.
Is rotation normal?
Is there no dropout of RF
signal?
YES
NO
Does signal
NO
appear at Test
Pin(TEO)?
1.3V
YES
Does signal appear at IC 502
Pin
26
NO Does GFS (IC503 pin 25)
show as below?
YES
Does laser light?
YES
Does TE2 signal
NO
appear at pin
of IC501?
YES
and Pin ?
27
YES
NO
- 2-4 -
NO
A
B
NO
53
Defective IC
801, pick up
and/or open
wire.
YES
Detective pattern.
Defective IC 501
NO
and/or IC 502
Defective pick-up
and/or connector.
NO
Defective IC 503.
Scratch in disc
initial read area.
Defective pick-up
adjustment focus offset.