Sharp SM-SX100 Service Manual page 52

SM-SX100
• It does not sound at the analog input (Line 1 and Line 2) alone.
Is any signal input to CNP116 or CNP117?
Yes
Does it not sound on both Line 1 and Line 2?
Yes
Is 5V supplied to drive the relays (RLY101, RLY102 and
RLY104)?
Yes
Is any signal supplied to the analog line amplifying units
Q613, Q614, Q617 and Q618?
Yes
Is any signal output from the analog line amplifying
units?
Yes
Is any signal output from CNP108?
Yes
Check the wiring to 1-bit amplifying unit, and 1-bit amplifying
unit.
• It does not sound on the digital input alone.
• It does not sound on Digitals 1 to 4 at all.
Is 5V supplied to Pin 3 of CNP801?
Yes
Is any digital signal output from Pin 9 of IC801?
Yes
Is any digital signal output from Pin 4 of IC802?
Yes
Is any digital signal input to P37 of IC804?
Yes
Is any digital signal from IC804 to IC806?
(DATA, MC-, WC, MCC)
Yes
Is any digital signal supplied from IC806 to IC807?
Yes
Is any initial setting signal supplied from Pins 38, 39 and
42 of IC807?
Yes
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Check the wiring from the input terminal to CNP116 and
No
CNP117.
Check the wiring from RLY101, RLY102, RLY104 and the
No
relays to the microcomputer IC904.
Check IC107.
No
Check the wiring from RLY201, RLY601, RLY602 and the
relays to the microcomputer IC904.
No
Check the line amplifying circuit.
No
Check IC108.
No
Check IC801.
No
Check the wiring of CNP801 and CNS801.
No
Check IC802.
Check the wiring of CNP801 and CNS801.
No
Check IC804 and IC805.
No
Check IC806.
No
Check the wiring from Pins 38, 39 and 42 of IC807 to the
No
microcomputer IC904.
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