LC-37GA9EK (serv.man8). Troubleshooting Tables - Sharp TV Service Manual (repair manual). Page 3

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.

No sound from EXT4 
(AUDIO) connecting an 
external input device.

No sound from EXT5 
(AUDIO) connecting an 
external input device.

<EXT1>
Is IN1-L audio signal sent 
from pin (6) of SCART1 
terminal (J1101) to pin 
(14) of IC3002 (VCT)?
Is IN1-R audio signal sent 
from pin (2) of SCART1 
terminal (J1101) to pin 
(13) of IC3002 (VCT)?

<EXT2>
Is IN2-L audio signal sent 
from pin (27) of SCART2 
terminal (J1101) to pin 
(12) of IC3002 (VCT)?
Is IN2-R audio signal sent 
from pin (23) of SCART2 
terminal (J1101) to pin 
(11) of IC3002 (VCT)?

<EXT3>
Is IN3-L audio signal 
sent from pin (3) of 
J1201 terminal to pin 
(16) of IC3002?
Is IN3-R audio signal 
sent from pin (5) of 
J1201 terminal to pin 
(15) of IC3002?

Is the audio signal 
properly sent from pins 
(28) and (27) of IC3002?

Check IC3002 or 
peripheral circuits.

Is the audio signal of 
pins (7) and (1) of IC303 
(OP-AMP) sent properly?

Check IC303 or 
peripheral circuits.

<EXT4>
Is D-SUB-L audio signal 
sent from J2702 to pin 
(15) of IC2704?
Is D-SUB-R audio signal 
sent from J2702 to pin 
(2) of IC2704?

Is D-SUB-L audio signal 
sent to pin (10) of 
IC3002?
Is D-SUB-R audio signal 
sent to pin (9) of 
IC3002?

<EXT5>
Is HDMI-L audio signal 
sent from J2701 to pin 
(14) of IC2704?
Is HDMI-R audio signal 
sent from J2701 to pin 
(5) of IC2704?

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 
(J1201) and 5 
(J1201) of EXT3 
and connection to 
an external input 
device.

Is HDMI-L audio 
signal sent to pin 
(10) of IC3002?
Is HDMI-R audio 
signal sent to pin (9) 
of IC3002?

Is the audio output 
signal of pins (13) and 
(16) of IC302/IC301 
(MAIN-AMP) normal?

Check IC302/IC301 
(MAIN-AMP),
HEADPHONE and 
peripheral circuits.

Check CONNECTOR 
(P301) and SP-BOX 
(right and left).

Check output of pins 
(13) and (3) of 
IC2704 and 
peripheral circuits.

Check that Option-
HDMI Setup-Audio 
select is set to 
"Analog".