Sharp LC-37XD10, Service Manual

Page: 36 / 190

LC-37XD10E/RU
4 – 3
No sound from external input devices (2) -1
No sound from an external input
device connected to EXT1
(SCART1). No sound from an external
input device connected to
EXT2 (SCART2). No sound from an external input
device connected to EXT3.
<EXT1>
Is IN1-L audio signal sent from
pin (6) of SCART1 terminal
(J1101) to pin (53) of IC3701
(MSP)?
Is IN1-R audio signal sent from
pin (2) of SCART1 terminal
(J1101) to pin (54) of IC3701
(MSP)?
YES
<EXT2>
Is IN2-L audio signal sent
from pin (27) of SCART2 ter-
minal (J1101) to pin (56) of
IC3701 (MSP)?
Is IN2-R audio signal sent
from pin (23) of SCART2 ter-
minal (J1101) to pin (57) of
IC3701 (MSP)?
YES
<EXT3>
Is IN3-L audio signal sent from
pin (3) of
J1201 terminal to pin (47) of
IC3701?
Is IN3-R audio signal sent from
pin (5) of J1201 terminal to pin
(48) of IC3701?
NO NO NO
Check pins (6) and (2) of
SCART1 and connection to an
external input device. Check pins (27) and (23) of
SCART2 and connection to
an external input device. Check pins 3 and 5 of EXT3
(J1201) and connection to an
external input device.
Is the audio signal properly sent from pins (28) and (27) of IC3701 ?
NO YES
Check IC3701 or peripheral circuits. Is the audio signal of pins (1)
and (7) of IC303 (OP-AMP)
sent properly? NO Check IC303 or peripheral circuits.
YES
Is the audio output signal of
pins (13) and (16) of IC302/
IC301(MAIN-AMP) normal? NO Check IC302/IC301 (MAIN-AMP), HEAD-
PHONE and peripheral circuits.
YES
. Check CONNECTOR(P301)
and SP-BOX(right and left).