Sharp MD-MT80W(S) Service Manual page 41

• 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 43?
Does waveform appear on IC901 pins 1, 2 and 23?
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 appear at TP201 (When monitoring
the RF waveform, set to MSL:80H using the control setting
item of EEPROM) when recording/Playback is performed
Does level of pins 86 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,
head, flexible PWB.
Is audio monitor output given in normal mode LINE IN
record?
Is waveform obtained on IC501 pins 2 and 3?
Is audio waveform observed on the pins 8 and 17 of IC703?
Check whether input waveform is observed on the pins 4
and 21 of IC703.
Yes
Yes
Yes
No
Yes
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 3, 4, 7, and 9 of
Yes
IC651, pins 1 and 2 of CN601. Check whether disc is record-
inhibited.
Check periphery of IC401 and IC101.
No
Check for soldering failure of IC201 .
No
Check waveforms of pins 8,10,11,12 of IC501, pins 70 to 73 of
Yes
IC201.
Check whether the pin 13 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/DOWN?
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MD-MT80W/90W/90/90C