Sharp CD-SW440N, Руководство по обслуживанию

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CD-SW440N
7 – 3
Check the TE waveform at pin 14 on U10.
(2) Tracking system check.
If the waveform shown in Figure 3 appears and soon after NO
DISC appears?
Yes
The tracking servo is not activated.
Check the peripheral circuits at pins 2, 3, 14 and 127 on U10,
pins 15, 16 and 26 on U12 and FFC.
No
"Initialization" is possible, but play is not possible?
Yes
A normal jump operation cannot be completed or the
beginning of the track cannot be found.
Check the around pin 127 on U10.
U10
U10
126
14
4
1
FOO
TEI
Figure 3
(3) Spin system check.
Press the OPEN/CLOSE switch without inserting a disc, and
then try starting the play operation.
1. The turntable rotates a little?
(Waveform drawing Figure 4)
Yes
The spin driver circuit is OK.
No
2. The turntable doesn't rotate. Check around pin 123 on U10, pins 17, 18 and 23 on U12.
Figure 4
1
5
U10
U10
126
123
FOO
DMO