Sharp MD-S301 Service Manual page 35

• "Normal playback"
When the address up to the cluster address has been proved to be normal in the TEST mode.
Is initialization performed normally in the high-reflection
disc playback mode?
No
Is the lead-in switch turned on when the optical pickup is
moved to the innermost periphery in the NORMAL mode?
(Is the level of pin 98 of IC401 Low?)
Yes
Is an attempt to read repeatedly the TOC part made on the
low-reflection disc?
Yes
Check position in the "INNER" mode.
• "Audio playback circuit"
When sound is not output although playback time display advances during continuous playback.
Is audio waveform observed on the pins 14 and 16 of
IC501?
Is audio waveform observed on the pins 1 and 7 of IC701?
Is audio waveform observed on the pins 3 and 4 of J701?
Check periphery of headphone jack and headphone.
• "Spindle motor fails to rotate"
Is waveform observed on the pins 24 and 25 of IC201 at the
focus gain rough adjustment step?
Yes
Is waveform observed on the pin 24 of IC601?
Yes
Is waveform observed on the pins 13 and 17 of IC901?
Yes
Replace the spindle motor.
Yes
Yes
Yes
Does playback time advance?
Yes
No
Check IC201, IC202 connection line.
Check the lead-in switch SW901, solder joint of mechanism
No
flexible PWB, pin 15 of CN601.
Replace disc.
No
Check the pins 70 to 72 and 74 of IC201, pins 1 to 3 and 6 of
No
IC501.
Check the pins 3 and 5 of IC701, pins 3 and 13 of IC702.
No
Is mute applied?
No
Check whether the level of pin 67 of IC401 is High.
Check periphery of IC201.
No
Replace IC601.
No
Check solder joint of L609, IC201, IC901, CN601, flexible PWB.
No
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MD-S301/S301W