Service manual

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CD-PC1881V
• When the CD tray fails to open or close.
Is there following voltage input in specific state of IC701 pin 19?
Open state: 0V
Close state: 0V
Intermediate state between open state and close state: 4.3V
Is H output to IC2 pin 24 or 25 for 7 seconds when the OPEN/
CLOSE key is pressed?IC91 is defective. Replace it.
Check the loading motor (M1) and the loading mechanism.
Yes
Yes
No
No
IC2 defective.
OK
Check the OPEN CLOSE SW and the wiring from the IC701
pin 19 to the OPEN CLOSE SW.
Check the wiring of the IC2 pins 24 and 25.
• The CD function will not work.
The CD operating keys don't work.
Check the CD, DSP, power supply, and 16.93 MHz clock, and
reset terminal.
Check the waveform of SCK, SO (DATA) and SI (COMM).
Yes
Yes
See if the pick-up is in the PICKUP IN SW position.
If the items mentioned above are OK, check the main
microcomputer IC701.
Yes
Yes
No
Is there following voltage input on the IC701 pin 21 in the
specific state?
In other states: 4.3V
When the CD mechanism is moved up: 0V
• When turntable fails to move.
Check the MECHA UP SW and the wiring from the IC701 pin
21 to the MECHA UP SW.
Yes
Yes
Check the wiring of IC2 pin 26.
OK
No
Is L output from the IC2 pin 26 during SEC when the disc skip
switch is pressed?
Check turntable motor and turntable mechanism.
IC2 defective.