Read Sharp QT-CD180 (serv.man5) Service Manual online
QT-CD180H/QT-CD180W
– 22 –
• Focus servo sawtooth wave failure.
Is +8.1V applied to the pins 21 and 22 (VCC) of IC803 ?
Is sawtooh wave output to the pin 66 (FOO) of IC802 ?
IC802 is faulty.
No
Yes
Yes
Is sawtooth wave obtained between pins 17 and 18 of IC803 ?
No
Check the PWB pattern of IC803.
Check the PWB pattern of IC803.
No
Is sawtooth wave obtained between pins 3 and 4 of BI801/
CNS801 ? (as shown above)
CNS801 ? (as shown above)
Yes
Check the PWB pattern between BI801/CNS801 and IC803.
No
BI801/CNS801 connection failure or optical pickup failure.
Yes
1.5~2.5sec
1.5~2.5sec
• Focus failure.
Does the optical pickup move up and down when the disc is
removed ?
removed ?
Is the following waveform output at the pin 62 (FEI) of IC802
when the disc is set ?
when the disc is set ?
Is the waveform shown above input at the pin 63 (SBAD) of
IC802 ?
IC802 ?
Yes
Yes
No
No
The optical pickup is faulty.
Check as stated in item "FOCUS SERVO SAWTOOTH WAVE
FAILURE".
FAILURE".
Yes
Check the periphery of IC801 and BI801/CNS801. Is it normal ?
No
Check the pattern between pin 13 of IC801 and pin 63 of IC802.
Check the periphery of IC801 and BI801/CNS801.
Check the periphery of IC801 and BI801/CNS801.
IC801 is faulty.
Yes
pin 62
pin 86
pin 63
(FEI)
(FOO)
(SBAD)
Click on the first or last page to see other QT-CD180 (serv.man5) service manuals if exist.