Sharp MD-MT180 Service Manual page 46

MD-MT180
• Audio playback circuit
Although the playback time display is acting., no sound is given during playback in the normal mode.
Is audio waveform output from IC501 pins 15 and 16?
Yes
Is audio waveform output from IC703 pins 8 and 17.
Yes
Is audio waveform output from J703A pins 2 and 3.
Yes
Check headphones jack, and periphery of headphone.
• 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 36?
Does waveform appear on IC601 pins 56, 57 and 58?
Replace the spindle motor.
Yes
Yes
Yes
Check IC201 pins 70 to 72, pin 74 and IC501 pins 9, 10, 11, 12.
No
Check the pins 4 and 21 of IC703.
No
Check whether there is defective solder joint of audio signal line
between IC703 and J703A
No
Check the IC201 periphery.
No
Replace. IC601
No
L605, IC201, IC601, CN601 and flex, etc. soldering check
No
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