Read Sharp LC-15M4E (serv.man3) Service Manual online
21
LC-15M4E
TROUBLE SHOOTING TABLE
(Continued)
No sound
fr
om fr
ont
speaker
s
Yes
No
Is pin (53) of
IC2001 at
“L
”?
No sound
fr
om rear
speaker
s
Chec
k all the settings on the microprocessor’
s adjust process men
u.
No sound
No
Are outputs at
pins (1) and (7)
of IC903 as
specified?
Yes
No
Are inputs and
outputs of
IC303 as
specified?
Yes
No
Are inputs at
pins (5) and (8)
as w
ell as
outputs at pins
(2) and (11), all
of IC301, as
specified?
Muting eff
ect is
on.
Chec
k the
FSMU line
.
Chec
k IC901,
IC903 and their
per
ipher
al
par
ts
.
Chec
k IC303
and its
per
ipher
al
par
ts
.
Chec
k the line
in question,
IC303 and its
per
ipher
al
par
ts
.
Yes
Chec
k the
speak
ers and
their per
ipher
al
par
ts
.
No sound
fr
om
headphone
Yes
No
Is pin (55) of
IC2001 at
“L
”?
Chec
k the
headphone and
its per
ipher
al
par
ts
.
Chec
k Q371,
J4310 and their
per
ipher
al
par
ts
.
Yes
No
Is pin (54) of
IC2001 at
“L
”?
No
Are input at pin
(5) as w
ell as
output at pin
(2) of IC302, as
specified?
Yes
Chec
k the
speak
er and its
per
ipher
al
par
ts
.
Chec
k the line
IC901, IC303
and their
per
ipher
al
par
ts
.
Muting eff
ect is
on.
Chec
k the
FSMU line
.
No sound
fr
om output
line
Yes
No
Is pin (52) of
IC2001 at
“L
”?
No
Are outputs at
pins (1) and (7)
of IC902 as
specified?
Yes
Chec
k the line
in question.
Chec
k the
LMUTE line
.
Chec
k IC902
and its
per
ipher
al
par
ts
.
