Sharp SM-SX1 (serv.man2) Service Manual ▷ View online
SM-SX1H
– 33 –
WAVEFORMS OF 1 BIT AMP. CIRCUIT
5
4
Observe
each pair.
each pair.
• QA1, QA5
• QA2, QA6
• QA3, QA7
• QA4, QA8
• QA2, QA6
• QA3, QA7
• QA4, QA8
Observe
each pair.
each pair.
• QA1, QA5
• QA2, QA6
• QA3, QA7
• QA4, QA8
• QA2, QA6
• QA3, QA7
• QA4, QA8
QA1
(QA2, 3, 4)
COLECTOR
QA5
(QA6, 7, 8)
COLECTOR
QA2
(QA1, 3, 4)
EMITER
QA6
(QA5, 7, 8)
EMITER
2
3
1
• OUTR(+), OUTR(-)
• OUTL(+), OUTL(-)
• OUTL(+), OUTL(-)
Observe
each pair.
each pair.
Observe
each pair.
each pair.
OUTR(+),
(OUTL(+))
(OUTL(+))
OUTR(-),
(OUTL(-))
(OUTL(-))
• RA5, RA7
• RA6, RA8
• RA6, RA8
Observe
each pair.
each pair.
• QA1, QA5
• QA2, QA6
• QA3, QA7
• QA4, QA8
• QA2, QA6
• QA3, QA7
• QA4, QA8
RA5
(RA6)
(RA6)
RA7
(RA8)
(RA8)
QA2
(QA1, 3, 4)
BASE
QA6
(QA5, 7, 8)
BASE
7
8
6
Observe Li and Hi of
ICA4 to 7 of each.
ICA4 to 7 of each.
Li
Hi
Observe SW section
of Lch and Rch of each.
of Lch and Rch of each.
Observe
each pair.
each pair.
• QA9, QA11
• QA10, QA12
• QA13, QA15
• QA14, QA16
• QA10, QA12
• QA13, QA15
• QA14, QA16
QA10
(QA9,13,14)
GATE
QA12
(QA11,15,16)
GATE
Set -22V at GND for observation of
6
to
8
.
Figure 33-1
Figure 33-2
Figure 33-3
Figure 33-4
Figure 33-5
Figure 33-6
Figure 33-7
Figure 33-8
SM-SX1H
– 34 –
TROUBLESHOOTING
No
• Power is not supplied.
Does AC100V stand between Pins 1 and 2 of the power
filter PWB connector CNP502?
filter PWB connector CNP502?
(LED does not come on and it does not sound.)
• Check the fuse F501.
• Check the parts on the power filter PWB.
• Check the wiring of the inlets SOC501 and CNS501.
• Check the parts on the power filter PWB.
• Check the wiring of the inlets SOC501 and CNS501.
Yes
No
Yes
Is any normal voltage is output from the power PWB
B1503/CNS503?
B1503/CNS503?
• Check the output voltage (OYT terminal) of UNT501 and
UNT502.
• Check the parts (L504 to L511, F502, FS503 and R503 to
R506) on the power PWB.
• Check the 1-bit amplification unit.
(Try to disconnect CNWAM4 and CNWAM3.)
(Try to disconnect CNWAM4 and CNWAM3.)
No
Yes
Is 5V supplied to Pin 13 of the microcomputer IC907?
• Check IC306 output.
• Check R391.
• Check R391.
No
Is any oscillating waveform found at Pins 14 (OSC2) and
15 (OSC1)?
15 (OSC1)?
• Check X900.
• Check IC907.
• Check IC907.
No
• It neither sound at the analog nor digital input.
Yes
Are the speaker relays RLY201 and RLY202 switched?
(when power is supplied and LED is lit.)
• Check whether 12V is supplied to RLY201 and RLY202 or not.
(Check the surroundings of Q201, Q202, R201 to R202.)
• Check whether Q203 and Q204 are on or not.
• Check the line Q203 and Q204 from Pin 41 of the
microcomputer IC907.
(Check the surroundings of Q201, Q202, R201 to R202.)
• Check whether Q203 and Q204 are on or not.
• Check the line Q203 and Q204 from Pin 41 of the
microcomputer IC907.
Are they properly wired to the 1-bit amplifying unit?
(CNWAM1, CNWAM2, CNWAM3, CNWAM4)
(CNWAM1, CNWAM2, CNWAM3, CNWAM4)
No
Yes
Is voltage properly supplied to 1-bit amplifier? (CNP306)
• Check whether the proper voltage is output from the AC
input filter CNP502 or not.
• Check whether RLY303 is activated or not.
• Check whether Q303 is on or not.
• Check the line Q303 from Pin 42 of the microcomputer
• Check whether Q303 is on or not.
• Check the line Q303 from Pin 42 of the microcomputer
IC907.
No
Yes
Is voltage properly supplied to 1-bit amplifier? (CNP305)
• Check -22V (around Q115 and Q114).
• Check 5V (around Q105 and Q106).
• Check reset 5V.
(Connection from Pin 21 of the microcomputer IC904.)
• Check 5V (around Q105 and Q106).
• Check reset 5V.
(Connection from Pin 21 of the microcomputer IC904.)
No
Is any signal output from the connectors CNP303 and
CNP304 for 1-bit amplifier?
CNP304 for 1-bit amplifier?
• Check CNS601A/B and main volume, VOL601.
• Check the IC107 output voltage which is supplied to drive
• Check the IC107 output voltage which is supplied to drive
the relay.
• Check the relays RLY601 and RLY602 and drive circuit.
Yes
Check the inside of the 1-bit amplifying unit.
SM-SX1H
– 35 –
No
Check IC801.
No
• It does not sound at the analog input (Line 1 and Line 2) alone.
Yes
Is any signal input to CNP116 or CNP117?
Check the wiring from the input terminal to CNP116 and
CNP117.
CNP117.
No
Yes
Does it not sound on both Line 1 and Line 2?
Check the wiring from RLY101, RLY102, RLY103 and the
relays to the microcomputer IC907.
relays to the microcomputer IC907.
No
Yes
Is 5V supplied to drive the relays (RLY101, RLY102 and
RLY103)?
RLY103)?
Check IC302.
No
Yes
Is any signal supplied to the analog line amplifying units
Q321, Q322, Q324 and Q323?
Q321, Q322, Q324 and Q323?
Check the wiring from RLY301, RLY302 and the relays to
the microcomputer IC907.
the microcomputer IC907.
No
Is any signal output from the analog line amplifying
units?
units?
Check the line amplifying circuit.
Yes
Is any signal output from CNP108?
Yes
Check the wiring to 1-bit amplifying unit, and 1-bit amplifying
unit.
unit.
No
• It does not sound on the digital input alone.
Yes
Is 5V supplied to Pin 8 of CNS800?
Check IC303.
No
Yes
Is any digital signal output from Pin 9 of IC102?
Check IC102.
No
Yes
Is any digital signal output from Pin 8 of IC103?
Check the wiring of CNS800 and CNP800.
Check IC103.
Check IC103.
No
Yes
Is any digital signal input to P37 of IC800?
Check the wiring of CNP800 and CNS800.
No
Is any digital signal from IC800 to IC801?
(DATA, MC-, WC, MCC)
(DATA, MC-, WC, MCC)
Check IC800 and IC802.
Yes
Is any digital signal supplied from IC801 to IC803?
Yes
Is any initial setting signal supplied from Pins 38, 39 and
42 of IC803?
42 of IC803?
• It does not sound on Digitals 1 and 4 at all.
No
Check the wiring from Pins 38, 39 and 42 of IC803 to the
microcomputer IC907.
microcomputer IC907.
Yes
To next page
SM-SX1H
– 36 –
No
Yes
Is any 1-bit signal from Pins 27 and 33 of IC803 output
to RLY801?
to RLY801?
Check IC808, IC809, IC811, IC812 and IC813.
No
Yes
Does RLY800 and RLY801 operate?
Check the operation of Q801 and Q802 and the wiring of
each to the microcomputer IC907.
each to the microcomputer IC907.
Check the wiring from CNP303 to CNP304 and
1-bit amplifying unit.
1-bit amplifying unit.
From the front page
No
• 1-bit amplifying section check (Signal is output from CNP303 and CNP304 but it does not sound.)
Yes
Is any signal output form Pins 2, 3, 5 and 6 of ICA1?
(Fig. 33-1)
(Fig. 33-1)
Check the waveform of the input pin, ICA1, voltage supplied
to ICA1 and ICA1 oscillating circuit.
to ICA1 and ICA1 oscillating circuit.
No
Are the waveforms of QA1 to QA8 proper?
(Fig. 33-3, Fig. 33-4, Fig. 33-5)
(Fig. 33-3, Fig. 33-4, Fig. 33-5)
Check ICA2, ICA3, QA1 to QA7.
Yes
No
Are the waveforms of ICA4 to ICA7 proper? (Fig. 33-6)
Check ICA4 to ICA7.
Yes
No
Are the waveforms of QA9 to QA16 proper?
(Fig. 33-7, Fig. 33-8)
(Fig. 33-7, Fig. 33-8)
Check RA53 to FA60 and QA9 to QA16.
Yes
No
Is any signal output from CNWAM6 and CNWAM7?
Check LA802 to LA808.
Check the soldering.
Check the soldering.
Yes
Check the surrounding of the relay PWB.
No
• 1-bit amplifying section check (power trouble/protector activation)
Yes
Don't the protector activate together with drop of voltage
±
22V if CNWAM4 and CNWAM3 are disconnected?
Recheck the main body section.
No
Does the oscillating circuit operate? Check Pin 9.
Replace ICA1.
Check CXA1 crystal and CA8, CA9.
Check CXA1 crystal and CA8, CA9.
Yes
Check ICA4 to ICA7, CA36 to CA39 and RA53 to RA60.
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