Sharp CD-C821W User Manual

CD-C811W/821W
– 42 –
• When the CD tray fails to open or close.
Is there following voltage input in specific state of IC701 pin 39?
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.
Yes
Yes
Yes
No
No
IC2 defective.
No
Check the periphery of IC3.
IC3 defective.
OK
OK
Check the OPEN/CLOSE switch and the wiring from the
IC701 pin 39 to the OPEN/CLOSE switch.(CD-C811W)
Check the wiring of the IC2 pins 24 and 25, IC3 pins 38 and 39.
• 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).
Yes
Yes
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
No
Is there following voltage input on the IC701 pin 41 in the
specific state?(CD-C811W)
In other states: 4.3V
When the CD mechanism is moved up: 0V
• When turntable fails to move.
Check the MECHA UP switch and the wiring from the IC701
pin 41 to the MECHA UP switch.(CD-C811W)
Is 4V output from the Q51 emitter during operation stated
above?
Yes
Yes
Check the wiring of IC2 pin 27 and Q51 pin 2.
OK
No
No
Is L output from the IC2 pin 27 during SEC when the disc skip
switch is pressed?
Yes
Check turntable motor and turntable mechanism.
Check Q51 and the periphery.
IC2 defective.
Is there following voltage input on the IC701 pin 42 in the
specific state?(CD-C821W)
Check the MECHA UP switch and the wiring from the IC701
pin 42 to the MECHA UP switch.(CD-C821W)
Is there following voltage input in specific state of IC701 pin 37?
(CD-C811W)
(CD-C821W)
Check the OPEN/CLOSE switch and the wiring from the
IC701 pin 37 to the OPEN/CLOSE switch.(CD-C821W)

Sharp CD-C821W Specifications

General

Brand	Sharp
Model	CD-C821W
Category	Stereo System
Language	English