Pioneer PRO-R04U Service Manual page 136

1
No sound from the speakers (1/2)
No sound from the speakers
A
No
Is sound muting set?
No
Is the volume set to 0?
No
B
Is it the only TV sound that
doesn't come out?
Yes
Is a signal output normally
from the FE (U7501)?
(11)
40
Yes
C
Is a signal output from
IC7503?
(26), (27)
41 42
Yes
Is a signal input to IC8002?
D
(62), (64)
43 44
Yes
Check around IC8002 and
check the communications
between IC8002 and the
microcomputer.
E
F
136
1
2
Yes
Cancel muting then check
again.
Yes
Raise the volume then
check again.
No
Check the communications
No
around the FE and between
the FE and the
B
microcomputer.
No
Check around IC7503.
B
Check the communications
No
between IC7503 and
B
IC8002.
2
3
Is it only the VIDEO 3
sound that doesn't come
out?
Yes
Is a signal input to IC8003?
(4), (11)
Yes
Check around IC8003 and
check the communications
between IC8003 and the
microcomputer.
Is it sound other than the
TV or VIDEO 3 that doesn't
come out?
Yes
Is a signal input to IC8002?
Yes
PDP-R04U
3
4
No
Check the communications
No
between the jack and
B
IC8003.
No
A
Check the communications
No
between the jack and
B
IC8002.
4