Service Manuals, User Guides, Schematic Diagrams or docs for : LG Audio FJ-X4AX fx4troub
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TROUBLE SHOOTING GUIDE (CDP)
Turn power on.
NO
Is power on? Check power supply circuit.
YES
NO
Does initial read work? Check laser circuit.
YES
Check focus circuit.
Check disc.
NO
Does it play? Check tracking servo circuit.
YES
NO
Does it output audio? Check audio circuit
YES
OK
-2-
Fails to initial read
Disc motor turns. Does laser light? A
YES
YES B
Does RF NO Does tracking NO Does signal NO Does TE1 signal NO
waveform servo work? appear at IC801 appear at pin 54
Lower envelope Defective IC
appear? 50 pin (TEO) of IC 801?
of IC801 74 801, pick up
(IC801 74 pin)
pin(RF) and/or short
waveform is flat. wire.
1.3V
YES YES
Defective pattern.
YES
Does signal appear at IC 803 NO Defective IC 801
Pin 26 and Pin 27 ?
and/or IC 803
YES Defective pick-up
and/or connector.
Is rotation normal? NO Does GFS (IC 802 pin 25 NO
Defective IC 801.
show as below?
YES
NO Scratch in disc
Is there no dropout of RF
signal? initial read area.
Defective pick-up
adjustment focus
YES offset or pick-up.
-3-
A Laser does not light.
Is "H" applied to pin 38 of IC 801?
YES NO
NO NO
Did pickup return to Is data transferred from
Defective -COM.
innermost circular? IC 101?
YES YES
Does voltage appear at NO
IC 803 pin 11 , 12 ? Defective IC 801, 802.
YES Defective slide motor
and/or connector.
Does it stop at inner pick Is defect output and input
circular after shift? YES to pin 2 of IC802?
NO Defective LMT SW
and/or connector.
OPEN CLOSE
YES Defective MICOM.
YES
NO
Is power supplied to laser Q801? Defective connector.
(Q801 collector: about 1.8V)
R801 1.0V YES
Defective Q801 and/or
YES
laser.
Does laser current flow? YES Defective laser and/or
1.0V across R801. R801 1.0V connector.
-4-
B Laser lights.
NO Does IC 801 out focus NO
Does lens move up/down? search signal? Defective IC 802.
YES
IC 801 pin 48 (FEO)
YES
Os focus search signal
applied to pin 1 , 2 of NO
Defective IC 803.
IC803?
Open activator and/or
YES connector.
Confirm Does IC801 pin 74 (RF) signal
initial appear even in low level?
read
with NO Open connector and/or
disc defective IC 801.
YES
Is laser output adjustment correct?
NO Incorrect turntable
height. Degraded laser
diode.
YES
Does FOK(focus ok) signal appear? NO
Defective IC 801.
IC801pin 74
(HF)
IC801 pin 40
(FOK)
YES
C
-5-
C
YES
Does FE1 signal appear? IC 801 59 pin
NO
Defective IC 801.
Open pick diode.
YES
Does FZC signal (focus zero cross signal)
appear at pin 31 of IC 801, ISTA(SENSE) NO
terminal? (Focus servo turns
Defective IC 801. ON by FZC signal
FER of FOK mod.)
SENSE
YES
Does SMON signal appear
NO
at pin 73 of IC 802? Defective pattern between IC 802 pin
27 , 36 , 37 , 38 and IC 101.
Does SMDP signal appear
at pin 75 of IC 802?
YES
Is drive voltage applied to disk motor?
NO
Defective IC 801, 803 and/or
peripheral circuit.
Start mode
YES
Defective disk motor and/or
insulation.
-6-
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