SHARP MDDR480H
Manual de Servicio

MD-DR470H/MD-DR480H
� Abnormal display
Is a waveform found in pins 8 to 10 of CN451 ? Is pin 2 (VCC) and pin 6 (GND) of CN451 normal ? No Check between IC401 and CN451. Check around IC401. Is a waveform found in pins 29 to 31 of IC401 ? Yes Yes No

Check the pattern and soldering of SW flexible PWB and LCD flexible PWB. If no problem is found, replace the LCD.

� Audio playback circuit
If playback time is counted but no sound is heard during continuous playback. Is an audio waveform found in pins 1 (TP721), 2 (TP722), 3 (TP723) and 4 (TP724) of J703 ? No Is there a pulse where duty varies in pins 2 and 5 of Q751, Q752, Q761 and Q762 ? No Is a pulse waveform found in pins 1, 4, 9 and 12 of IC751 and pins 1, 4, 9 and 12 of IC761 ? Are pins 2, 5, 10 and 13 of IC751 H ? Check pins 68, 69, 71 and 72 of IC201 and pin 19 of IC401. If the voltage of pin 6 of Q751 and Q752 and pin 3 of Q761 and Q762 is below 2 V when setting VOLUME to MAX, check the power supply circuit of IC813 and IC821. Check soldering of J703, the remote control and the earphones. Yes

Yes

No

� The spindle motor does not rotate.

Does a waveform appear in pins 26 and 27 of IC201 after ending the test mode AUTO2 ? Yes

No

Check the periphery of IC201.

Is a waveform found in pins 60 to 64 of IC601 ? Yes If there is no defect in soldering of IC601 and insertion of the flexible PWB, replace the spindle motor.

No

Check the periphery of IC601.

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