No sound from the speakers No Is sound muting set? No Is the volume set to 0? No
B
Yes
Cancel muting then check again.
Yes
Raise the volume then check again.
Is it the only TV sound that doesn't come out? Yes Is a signal output normally from the FE (U7501)? (11)
C
No
Is it only the VIDEO 3 No sound that doesn't come out? Yes Is a signal input to IC8003? (4), (11) No Check the communications between the jack and IC8003.
No Check the communications around the FE and between the FE and the microcomputer.
B
Yes
B
Yes Check around IC8003 and check the communications between IC8003 and the microcomputer.
Is a signal output from IC7501? (12) 40 Yes Is a signal output from IC7502? (26), (27)
B
No Check the communications between the FE and IC7501 and around IC7501.
No
Check around IC7502. Is it sound other than the No TV or VIDEO 3 that doesn't come out? Yes Is a signal input to IC8002?
41 42
Yes
B
A
No Check the communications between IC7502 and IC8002.
D
Is a signal input to IC8002? (62), (64)
43 44
Yes
B
B
Yes
No Check the communications between the jack and IC8002.
E
Check around IC8002 and check the communications between IC8002 and the microcomputer.
