Sharp MD-C2 Service Manual page 75

• Record and playback operation
Insert the low reflection disc, and after verifying the audio output in the normal mode playback set the record/playback TEST mode
Recording from start address cannot be performed.
Yes
Is RF waveform output to the pin 1 IC1201 or TP1201 when
playback is performed after recording?
No
Does the level of pins 3 and 26,39 of IC1401 and the pins 9
and 19 of CNS1101 and the pins 7 and 23 of CNS1101 in
record state differ from that in playback state?
Yes
Does RF pattern appear on the pin 50 of IC1201?
Yes
Check the IC1300, Q1300 to 1303 and CN1300.
Is input waveform given to the pins 22 and 24 of CN1501 in
AUX input record in the NORMAL mode?
No
Is input waveform given to the pins 3 to 5 of IC1701?
Yes
Check the periphery of IC1701, check the pins 70, 71, 72,
and 73 of IC1201.
• Focus servo failure
Is waveform on the pins 27 and 28 of IC1101 normal in the TEST
mode focus gain coarse adjustment step?
Yes
Is level of pin 81 of IC1201 changed from H to L?
Is pulse waveform output to the pin 82 of IC1201?
Yes
Does the pulse waveform duty of pins 18 and 19 of IC1201
change?
Yes
Does waveform change on the pins 27, 28, 31 and 32 of
IC1601?
Yes
Does waveform change on the pins 1 and 3 of CN1101 and
the pins 2 and 4 of CN1901 ?
Yes
Check the pickup.
Check whether the disc is record-prohibited.
No
Yes
Check periphery of IC1401, CN1910 and
CNS1101.
No
Check for IC1201 soldering failure.
No
Check the system PWB.
No
Check connection between IC1701 and CN1501.
No
Check waveform on the pins 9 and 10 of IC1101 and soldering joint.
No
Check waveform on the pins 8 and 9 of IC1201 and soldering joint.
No
Check soldering joint and part of IC1201.
No
Check soldering joint and part of IC1601.
No
Check soldering joint and peripheral parts of CN1101 and CN1910.
No
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MD-C2