LC-37GA9EK (serv.man8). Troubleshooting Tables - Sharp TV Service Manual (repair manual). Page 2

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33
 LC-26GA5E
 LC-32GA5E
  LC-32GA9E/LC-32BV9E
  LC-37GA9E/LC-37BV9E
Troubleshooting Table (continued)
29
LC-32/37GA9E
LC-32/37BV9E
TROUBLESHOOTING TABLE
 (Continued)
No sound (1) (during the reception of TV broadcasting)
No audio output during UHF/VHF reception
Checklist:
1) Is the volume set to MIN or MUTE on the remote control? ••• Set the desired volume.
2) Are headphones connected to HEADPHONE (J1301)? ••• Disconnect them.
3) Is ANT-CABLE disconnected or connected improperly? ••• Connect it correctly as per the operation manual.
NO
Is the audio signal (L/R) sent from pins (28) and (27) of IC3002 
(VCT)?
NO
YES
Is the audio signal of pins (3) 
and (5) of IC303 (OP-AMP) 
sent properly?
(AV-UNIT)
(TUNER)
Check IC303 or peripheral 
circuits.
NO
YES
YES
Is the audio signal of pin (4) 
of IC301/IC302 (AUDIO-
AMP) sent properly?
Check HEAD-PHONE 
(J1301) or peripheral 
circuits.
NO
Is the audio signal output of 
pins (2) and (4) of P301 
(AUDIO-CONNECTOR) 
normal?
YES
Check SP-BOX (right and 
left) and wire harness.
Check P301 (AUDIO-
CONNECTOR) and 
peripheral circuits.
YES
NO
Is the audio signal (SIF) sent 
from pin (1) of CONNECTOR 
(SC2705)?
Check pin (31) of IC3002 
(VCT) and peripheral 
circuits.
YES
Is the SIF signal (SIF_IN1+) 
sent to pin (31) of IC3002 
(VCT)?
Check whether +5V and +8V 
are supplied to pins (18) and 
(33) of IC3002 respectively.  
Or, check peripheral circuits.
YES
NO
NO
NO
NO
Is the audio signal (SIF) sent 
from pin (12) of IC201 (IF-
DEMOD)?
Check Q203 (AMP) and 
peripheral circuits.
YES
Is the SIF signal sent to pins 
(23) and (24) of IC201 (IF-
DEMOD)?
Check IC201 and peripheral 
circuits.
YES
Is the IF signal sent from pin 
(8) of TUNER (TU201)?
Check FL202 and peripheral 
circuits.
YES
Check whether 33V and 5V 
are supplied to pins (9) and 
(7) of TUNER (TU201) 
respectively. Check SDA/SCL 
and AGC signal.
Replace TUNER (TU201).
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