SHARP MD-MT90
Service Manual

MD-MT80W/90W/90/90C
� 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? Yes

No

Check the IC201 periphery.

Does waveform appear on the IC601 pin 43? Yes Does waveform appear on IC901 pins 1, 2 and 23? Yes

No

Replace. IC601

No

L608, IC201, IC901, CN601 and flex, etc. soldering check

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? No 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 No Does level of pins 86 of IC401 and pin 17 of IC101 change depending on record and playback? Yes Yes Yes Check voltage of pins 52 and 53 of IC201, pins 3, 4, 7, and 9 of IC651, pins 1 and 2 of CN601. Check whether disc is recordinhibited.

No

Check periphery of IC401 and IC101.

Is RF pattern output from IC201 pin 50? Yes 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.

No

Check for soldering failure of IC201 .

Is audio monitor output given in normal mode LINE IN record? No

Yes

Check waveforms of pins 8,10,11,12 of IC501, pins 70 to 73 of IC201.

Is waveform obtained on IC501 pins 2 and 3? No

Yes

Check whether the pin 13 of IC501 and the pin 59 of IC201 are in H state.

Is audio waveform observed on the pins 8 and 17 of IC703? Yes Check whether input waveform is observed on the pins 4 and 21 of IC703.

No

Does voltage on the IC701 pins 13 to 15 change in case of record VOLUME UP/DOWN?

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