MD-DR470H/MD-DR480H
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Check pins 68, 69, 71 and 72 of IC201 and pin 19 of IC401.
No
No
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.
Yes
No
Is there a pulse where duty varies in pins 2 and 5 of Q751, Q752,
Q761 and Q762 ?
Check soldering of J703, the remote control and the earphones.
Yes
Yes
Yes
Check between IC401 and CN451.
No
Check around IC401.
• Audio playback circuit
Is an audio waveform found in pins 1 (TP721), 2 (TP722), 3
(TP723) and 4 (TP724) of J703 ?
If playback time is counted but no sound is heard during continuous playback.
• The spindle motor does not rotate.
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 ?
• Abnormal display
No
Is a waveform found in pins 8 to 10 of CN451 ?
Is pin 2 (VCC) and pin 6 (GND) of CN451 normal ?
Is a waveform found in pins 29 to 31 of IC401 ?
Check the pattern and soldering of SW flexible PWB and LCD
flexible PWB. If no problem is found, replace the LCD.
No
Yes
No
Yes
Check the periphery of IC201.
If there is no defect in soldering of IC601 and insertion of the
flexible PWB, replace the spindle motor.
Check the periphery of IC601.
Does a waveform appear in pins 26 and 27 of IC201 after
ending the test mode AUTO2 ?
Is a waveform found in pins 60 to 64 of IC601 ?
Содержание MD-DR470H
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