Sharp LC-26SA1E/RU Service Manual page 36

LC-26SA1E/RU, LC-32SA1E/RU
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.
Is the audio signal (L/R)
sent from pins (28) and
(27) of IC3002 (VCT)?
(AV-UNIT) YES
Is the audio signal of pins
(3) and (5) of IC303
(OP-AMP) sent properly?
YES
Is the audio signal of pin
(4) Of IC301/IC302
(AUDIO-AMP) sent
properly?
YES
Is the audio signal output
of pins (2) and (4) of P301
(AUDIO-CONNECTOR)
normal?
YES
Check Speaker (right and
left) and wire harness.
NO
NO Check IC303 or
peripheral circuits.
NO Check HEAD-PHONE
(J1301) or peripheral
circuits.
NO Check P301 (AUDIO-
CONNECTOR) and
peripheral circuits.
Is the SIF signal (SIF_IN+)
sent to pin (31) of IC3002
(VCT)?
NO
Is the audio signal (SIF)
sent from pin (1) of
CONNECTOR (SC2705)?
(TUNER) NO
Is the audio signal (SIF)
sent from pin (12) of IC201
(IF-DEMOD)?
NO
Is the SIF signal sent to
pins (23) and (24) of IC201
(IF-DEMOD)?
NO
Is the IF signal sent from
pin (11) of TUNER
(TU201)?
NO
Check whether 33V and
5V are supplied to pins (9)
and (7) of TUNER (TU201)
respectively. Check SDA/
SCL and AGC signal.
6 – 2
Check whether +5V and
+8V are supplied to pins
YES
(33) and (18) of IC3002
respectively. Or, check
peripheral circuits.
YES Check pin (31) of IC3002
(VCT) and peripheral
circuits.
YES Check Q203 (AMP) and
peripheral circuits.
YES Check IC201 and
peripheral circuits.
YES Check FL202 and
peripheral circuits.
YES Replace TUNER (TU201).