Sharp MS722 Service Manual - Page 43

• The spindle motor fails to run.Does the head move MD-MS722/C/W/MS721W Does the waveform appear on the IC201 pins 24 and 25 after TEST mode AUTO2 completion and in this state? Yes Does waveform appear on the IC601 pin 13? Yes Does waveform appear on IC901 pins 1, 19 and 20? Yes Replace the spindle motor. No Check the IC201 periphery. No Replace. IC601 No L608, IC201, IC901, CN601 and flex, etc. soldering check • 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 Yes Check voltage of pins 52 and 53 of IC201, pins 2, 4, 7, and 9 of IC651, pins 3 and 14 of CNS601. Check whether disc is record- inhibited. Yes Does the RF waveform of TP201 appear when playback is No Does level of pins 34 of IC401 and pin 17 of IC101 change depending on record and playback? Check periphery of IC401 and IC101. No Yes 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, Q351 to 354, head, flexible PWB. No Check for soldering failure of IC201 . Is audio monitor output given in normal mode LINE IN record? No Is waveform obtained on IC501 pins 3 and 6? No Is audio waveform observed on the pins 18 and 19 of IC703? Yes Check whether input waveform is observed on the pins 5 and 6 of IC703. Yes Check waveforms of pins 9 to 12 of IC501, pins 70 to 73 of IC201. Check whether the pin 7 of IC501 and the pin 59 of IC201 are in Yes H state. Does voltage on the IC701 pins 13 to 15 change in case of No record VOLUME UP/DWN? - 43 -