Sharp QT-CD210 Service Manual page 15

• Laser failure.
Is +5V applied to the emiter of Q204 ?
Yes
Is +5V applied to the collector of Q204 ?
Yes
Is +5V applied to the pin 75 (VDD) of IC802 ?
Yes
Is +5V applied to the pin 1 (VCC) of IC801 ?
Yes
Is +0V applied to the pin 74 (SEL) of IC802 ?
Yes
Is approx. 1.8V applied to the collector of Q801.
Yes
Check BI801/CNS801. If it is normal, the optical pickup is
faulty.
• Focus failure.
Does the optical pickup move up and down when the disc is
removed?
Yes
Is the following waveform ouput at the pin 62 (FEI) of IC802
when the disc is set?
Yes
Is the waveform shown above input at the pin 63 (SBAD) of
IC802?
Yes
IC801 is faulty.
pin 62
(FEI)
pin 86
(FOO)
pin 63
(SBAD)
Check the PWB pattern of Q204.
No
Check the peripheral parts of IC803 and Q204.
No
Check the PWB pattern between collector of Q204 and pin 75 of
No
IC802.
Check the PWB pattern between collector of Q204 and pin 1 of
No
IC801.
Check the laser come on when pattern cut between pin 8 (SEL) of
No
IC801 and pin 74 (SEL) of IC802.
Check the peripheral parts of IC801 and Q801. If it is normal, the
No
optical pickup is faulty.
Check as stated in item "FOCUS SERVO SAWTOOTH WAVE
No
FAILURE".
Check the periphery of IC801 and BI801/CNS801. Is it normal?
No
Yes
The optical pickup is faulty.
Check the pattern between pin 13 of IC801 and pin 63 of IC802.
No
Check the periphery of IC801 and BI801/CNS801.
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QT-CD210/C