Sharp XL-35 Service Manual page 35

• Track search failure
Does the sled motor run in FF/REW state when the SERVO
TEST MODE "STEP1" is set?
Yes
Is the following wave output to the pin 27 (TRO) of IC801
during track search in normal playback?
Yes
Is the following wave output to the pins 20(TEOUT) of IC802
during track search in normal playback?
Yes
Is the above wave output to the pins 33 (TE) of IC801 during
track search in normal playback?
Yes
Is the following wave output to the pin 38 (/RFDET) of IC801
during track search in normal playback?
Yes
/RFDET
Normal.
• Sled motor operation failure.
Is following sled feed signal input the pin 3 (VIN1) of IC804
when FF/REW key is pressed after the CD TEST MODE
"STEP 1" is seted?
Yes
Is following sled feed signal output the pins 1 and 2 of IC804
when FF/REW key is pressed after the CD TEST MODE
"STEP 1" is seted?
Yes
Is sled feed voltage applied between both terminals of sled
motor?
Yes
Check the CD mechanism (periphery of sled motor).
If the sled motor does not run when DC2.0V is applied to
both terminals of sled motor, the sled motor is faulty.
• Sled servo failure.
Is following sled signal output the pin 3 (VIN1) of IC804 during
playback?
Yes
VIN1
Normal.
TRO
TEOUT
TE
FF REW
VIN1
FF REW
SL ±
Check as stated in item "SLED MOTOR OPERATION FAILURE".
No
IC801 failure.
No
Check the PWB pattern between pin 27 (TRO) of IC801 and pin
No
19 of IC804.
Check the PWB pattern between pins 17 and 18 of IC804 and
Optical pickup.
If OK. Optical pickup failure.
Check the PWB pattern between pin 20 (TEOUT) of IC802 and pin
No
33 of IC801. If OK. IC802 failure.
Check the PWB pattern pin38 (/RFDET) of IC801 and pin8 (ARF) and
No
pin15 (NRFDET) of IC802 . If OK. IC802 failure.
C801 is faulty.
No
IC804 is faulty.
No
Check the CNW803/CNS803.
No
IC801 is faulty.
No
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XL-35/35C