SHARP CD-C1831V Repair Manual

CD-C1831V
Y When the CD tray fails to open or close.
Is there following voltage input in specific state of IC701 pin 19?Check the OPEN CLOSE SW and the wiring from the IC701
No
Open state: 0Vpin 19 to the OPEN CLOSE SW.
Close state: 0V
Intermediate state between open state and close state: 4.3V
Yes
Is H output to IC2 pin 24 or 25 for 7 seconds when the OPEN/Check the wiring of the IC2 pins 24 and 25.
CLOSE key is pressed?IC91 is defective. Replace it.No
OK
YesIC2 defective.
Check the loading motor (M1) and the loading mechanism.
Y The CD function will not work.
The CD operating keys don't work.
Yes
Check the CD, DSP, power supply, and 16.93 MHz clock, and
reset terminal.
Yes
Check the waveform of SCK, SO (DATA) and SI (COMM).
Yes
See if the pick-up is in the PICKUP IN SW position.
Focus search is
Yes 0.5sperformed two
0.50 Vtimes when play
operation is done
If the items mentioned above are OK, check the mainwithout disc.IC1 16 FD
microcomputer IC701.
Y The CD operating keys work.
0.5s
0.50 V
IC1 7 TE
Check the Focus - HF system.
1
2
Playback can be performed without a disc.
Figure 40
Yes
Does the pick-up move up and down twice?Focus search OK
Yes
No
Does the output waveform of IC1(16)(FD) match that shown in
Check the area around IC3-CNP2.
Fig. 40?
Yes
No
Check the IC1(50)(CLK) line, 4MHz.
Check the microcomputer data on pins (51)(CL), (52)(DAT)
and (53)CE.
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