Sharp XL-35 Service Manual page 33

• Focus servo sawtooth wave failure.
Is sawtooh wave output to the pin 28 (FOO) of IC801 ?
Yes
Is +6.2V applied to the pins 21 and 22 (VCC) of IC804 ?
Yes
Is sawtooth wave obtained between pins 26 and 27 of IC804 ?
Yes
1.5~2.5sec
Is sawtooth wave obtained between pins 3 and 4 of CNW801/
CNS801 ? (as shown above)
Yes
CNW801/CNS801 connection failure or optical pickup failure.
• Spindle motor clv servo failure.
Is following wave output to the pin 11,12 of IC804 when the CD
TEST MODE "STEP 3" is changed to " STEP 4" ?
Yes
VO2
Is above wave obtained between pins 9 and 10 of IC804 ?
Yes
Is above wave obtained between pins 5 and 6 of CNW801/
CNS801 ?
Yes
CNW801/CNS801 connection failure or optical pickup failure.
1.5~2.5sec
IC801 is faulty.
No
Check the PWB pattern between pin 5 of CNS605 and IC804.
No
Is +5V applied to the pin 7
No
(MUTE) of IC804 ?
Yes
Check the PWB pattern between pin 28 (FOO) of IC801 and pins
24 and 25 of IC804. If OK. IC804 is faulty.
Check the PWB pattern between CNW801/CNS801 and IC804.
No
Check the procedure in "HF ERROR".
No
If OK. IC801 is faulty.
Check the PWB pattern between pin 24,25 of IC801 and pins 9
No
and 10 of IC804. If OK. IC804 is faulty.
Check the PWB pattern between CNW801/CNS801 and IC804.
No
– 33 –
XL-35/35C
Check the PWB pattern
between pin 7 of IC804
No
and pin 60 (CD STB) of
IC701.