SM-SX1/SX1W
– 35 –
No
Check IC801.
No
• No 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.
No
Yes
No sound on both Line 1 and Line 2?
Check the wiring from RLY101, RLY102, RLY103 and the
relays to the microcomputer IC907.
No
Yes
Is 5V supplied to drive the relays (RLY101, RLY102 and
RLY103)?
Check IC302.
No
Yes
Is any signal supplied to the analog line amplifying units
Q321, Q322, Q324 and Q323?
Check the wiring from RLY301, RLY302 and the relays to
the microcomputer IC907.
No
Is any signal output from the analog line amplifying
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.
No
• No 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.
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)
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?
• No sound on Digitals 1 and 4 at all.
No
Check the wiring from Pins 38, 39 and 42 of IC803 to the
microcomputer IC907.
Yes
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