Sharp SM-SX100 Service Manual page 54

SM-SX100
• 1-bit amplifying section check (power trouble/protector activation)
Don't the protector activate together with drop of voltage
±32V if CNWAM4 and CNWAM3 are disconnected?
Yes
Does the oscillating circuit operate? Check Pin 9.
Yes
Check ICA4 to ICA7, CA36 to CA39, QA9 to QA16 and
RA53 to RA60.
* When protection is activated, even if the function is switched, switching is not possible. Moreover, the volume is not variable, and
the volume indicator does not change. It is released when the power switch is turned off.
1
• OUTR(+), OUTR(-)
• OUTL(+), OUTL(-)
Observe
each pair.
OUTR(+),
(OUTL(+))
OUTR(-),
(OUTL(-))
Figure 54-1
3
• QA1, QA5
• QA2, QA6
• QA3, QA7
• QA4, QA8
QA2
Observe
(QA1, 3, 4)
each pair.
BASE
QA6
(QA5, 7, 8)
BASE
Figure 54-2
4
• QA1, QA5
• QA2, QA6
• QA3, QA7
• QA4, QA8
QA2
Observe
(QA1, 3, 4)
each pair.
EMITER
QA6
(QA5, 7, 8)
EMITER
Figure 54-3
5
• QA1, QA5
• QA2, QA6
• QA3, QA7
• QA4, QA8
Observe
each pair.
QA1
(QA2, 3, 4)
COLECTOR
QA5
(QA6, 7, 8)
COLECTOR
Figure 54-4
Recheck the main body section.
No
Replace ICA1.
No
Check CXA1 crystal and CA8, CA9.
6
Observe Li and Hi of
ICA4 to 7 of each.
Li
Hi
7
• QA9, QA11
• QA10, QA12
• QA13, QA15
• QA14, QA16
Observe
QA10
each pair. (QA9,13,14)
GATE
QA12
(QA11,15,16)
GATE
8
Observe SW section
of Lch and Rch of each.
– 54 –
Figure 54-5
Figure 54-6
Figure 54-7