Sharp MD-MS701H Service Manual page 41

• Abnormal display
Is waveform output from CNS 482 pins 1 to 3?
Are the pin7 (VCC) and pin 6 (GND) normal?
Yes
Check for pattern breakage of flexible PWB, check for
defects of display microcomputer (replace the display unit).
• Playback state cannot be set
When it has been ascertained that the address up to cluster address is normal in the TEST mode.
Is initialization performed normally in case of high- reflection
disc playback?
No
Is the lead-in photointerrupter set to OFF when the optical
pickup moves to the innermost periphery in NORMAL mode?
(Is TP660 in H level?).
Yes
Ia an attempt to repeat repeatedly the TOC part performed
on the low-reflection disc?
Yes
Position check in INNER mode
• Audio playback clrcult
Although the playback time display is acting., no sound is given during playback in the normal mode.
Is audio wavefrom output from IC501 pins 19 and 20?
Yes
Is audio wavefrom output from IC703 pins 18 and 19.
Yes
Is audio wavefrom output from J703 pins 3 and 4.
Yes
Check headphones jack,and periphery of headphone.
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No
Yes
No
No
No
No
No
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Is waveform output from IC 401 pins 45 to 47?
Yes
Check between IC401 and
CNS482.
Does the playback time display advance?
Check IC201 and IC202 connection line.
Check the lead-in photointerrupter, mechanical flex
PWB soldering and CNS601 connection.
Replace the disc.
Check IC201 pins 70 to 72, pin 74 and IC501 pins 9, 10, 11,
15
Check the pins 5 and 6 of IC703.
Check whether there is defective solder joint of audio signal
line between IC703 and J703
MD-MS701H/MS702H
No
Check the periphery of IC401.
No