Sharp CD-C811W Service Manual page 42

CD-C811W/821W
• When turntable fails to move.
Is there following voltage input on the IC701 pin 41 in the
specific state?(CD-C811W)
Is there following voltage input on the IC701 pin 42 in the
specific state?(CD-C821W)
When the CD mechanism is moved up: 0V
In other states: 4.3V
Is L output from the IC2 pin 27 during SEC when the disc skip
switch is pressed?
Is 4V output from the Q51 emitter during operation stated
above?
Check turntable motor and turntable mechanism.
• When the CD tray fails to open or close.
Is there following voltage input in specific state of IC701 pin 39?
(CD-C811W)
Is there following voltage input in specific state of IC701 pin 37?
(CD-C821W)
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 button is pressed? IC3 is defective. Replace it.
Is 4V output between IC3 pins 38 and 39 during operation
stated above?
Check the loading motor (M3) and the loading mechanism.
• The CD function will not work.
The CD operating buttons 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).
See if the pick-up is in the PICKUP IN switch position.
If the items mentioned above are OK, check the main
microcomputer IC701.
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Check the MECHA UP switch and the wiring from the IC701
pin 41 to the MECHA UP switch.(CD-C811W)
No
Check the MECHA UP switch and the wiring from the IC701
pin 42 to the MECHA UP switch.(CD-C821W)
Check the wiring of IC2 pin 27 and Q51 pin 2.
No
Check Q51 and the periphery.
No
Check the OPEN/CLOSE switch and the wiring from the
No IC701 pin 39 to the OPEN/CLOSE switch.(CD-C811W)
Check the OPEN/CLOSE switch and the wiring from the
IC701 pin 37 to the OPEN/CLOSE switch.(CD-C821W)
Check the wiring of the IC2 pins 24 and 25, IC3 pins 38 and 39.
No
Check the periphery of IC3.
No
– 42 –
OK
IC2 defective.
OK
IC2 defective.
OK
IC3 defective.