Sharp LC-32DH57RU, LC-32DH57S Service Manual page 32

LC-32DH57E/RU/S
No audio output during DTV
reception
Checklist:
1) Is the volume set to MIN or MUTE on the remote control? ••• Set the desired volume.
2) Is ANT-CABLE disconnected or connected improperly? ••• Connect it correctly as per the operation manual.
3) Attention: The terminal of IC3303 (VCT) cannot be actually checked by hiding oneself, and check it with another terminal of the same line,
please.
(MAIN-UNIT)
Is the audio signal
(AOUT_SP_L/R) output
from pins (H26) and (H25) of
IC3303 (VCT)?
(MAIN-UNIT) YES (OUTPUT_SIDE)
Is the audio signal
(SPKOUT_L/R) output
form pins (17) and (18) of
IC1302 (A-SW) normally?
YES
Is the audio signal (LCH±/
RCH±) output form pins
(31) (27) and (11) (14) of
IC2701 (A-AMP) prop-
erly?
YES
Is the audio output signal
outputted to pins (1)-(4) of
SP-Connector (P2701)
normally?
YES
Is the SP-Wire harness
(SP) connected and oper-
ated orthopedically nor-
mally?
YES
Check right and left SP-
BOX, and exchange
defective SP-BOX
(R: RSP-ZA392WJZZ/
L: RSP-ZA391WJZZ)
No sound (1-2) (during the reception of DTV broadcasting)
NO
NO Check S9V power supply
(10) (15) pin, D3.3V power
supply (3) (36) pin, and
AUSW-mute signal (29)
pin of IC1302 (A-SW) or
the peripheral circuits.
NO Check AMP12.5V power
supply (1) (10) pin, AMP-
STBY input signal (17) pin,
and audio-mute signal pin
(19) of IC2701 (A-AMP) or
the peripheral circuits.
NO Check SP-Connector
(P2701) and peripheral cir-
cuits.
NO Correct an abnormal part
of SP- harness.
A-BLOCK
(MAIN-UNIT)
Is the digital IF signal
(D_IF±) input to pins
(T25) (R25) of IC3303
(VCT)?
NO
Is the digital IF signal
(D_IF±) output from pins
(17) (16) of tuner
(TU1102)?
NO
Check whether the IF5V
power supply is sup-
plied to pin (3) of tuner
(TU1102).
YES
Check whether the I2C
signal (SDA/SCL) is
functioning by pin (9) (8)
of tuner (TU1102).
YES
Check whether IF_AGC
is functioning between
pins (E24) of IC3303
and pin (15) of tuner
(TU1102)
YES
Replace tuner
(TU1102).
4 – 6
(TUNER SIDE)
YES Check whether there
are a power supply of
IC3303 (VCT), the short
circuit, and other abnor-
malities.
YES Check whether there
are open-circuit or
short-circuit between
tuner (TU1102) and
IC3303.
NO Check whether there
are open-circuit or
short-circuit between
Q1105 (5V-REG) and
tuner (TU1102).
NO Pursue an I2C line and
look for the part of an
open circuit or the Short
circuit.
NO Check whether there is
an open circuit or the
short circuit in an
IF_AGC signal line.