Sharp MS722 - MiniDisc Recorder - Metallic Service Manual page 43

• The spindle motor fails to run.Does the head move
Does the waveform appear on the IC201 pins 24 and 25 after
TEST mode AUTO2 completion and in this state?
Does waveform appear on the IC601 pin 13?
Does waveform appear on IC901 pins 1, 19 and 20?
Replace the spindle motor.
• Recording/playback operation
Insert a low reflection disc, and ascertain audio output by normal playback, and then set TEST REC mode.
Does the head move down, failing to start record even
when the continuous record mode is set after address?
Does the RF waveform of TP201 appear when playback is
Does level of pins 34 of IC401 and pin 17 of IC101 change
depending on record and playback?
Is RF pattern output from IC201 pin 50?
Check whether there is any damage in IC101, periphery of
laser diode.
Check for defects of IC351 in head drive flexible PWB,
Q351 to 354, head, flexible PWB.
Is audio monitor output given in normal mode LINE IN
record?
Is waveform obtained on IC501 pins 3 and 6?
Is audio waveform observed on the pins 18 and 19 of
IC703?
Check whether input waveform is observed on the pins 5
and 6 of IC703.
Yes
Yes
Yes
No
No
Yes
Yes
No
No
Yes
Check the IC201 periphery.
No
Replace. IC601
No
L608, IC201, IC901, CN601 and flex, etc. soldering check
No
Check voltage of pins 52 and 53 of IC201, pins 2, 4, 7, and 9 of
Yes
IC651, pins 3 and 14 of CNS601. Check whether disc is record-
inhibited.
Yes
Check periphery of IC401 and IC101.
No
Check for soldering failure of IC201 .
No
Check waveforms of pins 9 to 12 of IC501, pins 70 to 73 of
Yes
IC201.
Check whether the pin 7 of IC501 and the pin 59 of IC201 are in
H state.
Yes
Does voltage on the IC701 pins 13 to 15 change in case of
No
record VOLUME UP/DWN?
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MD-MS722/C/W/MS721W