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1
Pickup (P.U.) transmission initial
operation does not occur.
Does pulse of
1.65V 1.65V develop at
pin 162 of IC401?
Y
Check feed gear.
3
Does focus search
voltage of 1.65V 0.4V develop
at pin 23 of IC503 (E544)?
Y
Does search signal
output at both edges of focus coil?
(Pins 15 to 18 of CN501)
Y
Check pickup head
and wiring.
The pickup transmission initial operation is carried out to
determine the initial position by transmitting the pickup to the
innermost position once (start-limit switch (pin 4 of CN503)
develops "L".) and to the external direction at low speed
(start-limit switch develops "H", turning off the switch.).
N
Check BUS between IC401-IC306
and oscillation.
Fig. 1-3-2
2-1
"No disc" misjudgement display of
disc presence.
Does lens move with
N
UP/DOWN full stroke in
focus direction?
Y
N
Is laser current normal?
Y
Does RFSB signal
develop more than 0.3V?
Y
Check peripheral
circuit of IC605.
N
Check IC401.
N
Check IC503.
Fig. 1-3-3
N
Check IC502.
Lens cleaning.
Replace pickup head.
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