Sharp Aquos LC 26D7U, Service Manual

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50
LC-26D7U
LC-32D7U
LC-37D7U
TROUBLE SHOOTING TABLE
(Continued)
NO NO NO NO NO NO
YES YES YES
YES YES
YES
YES YES YES
YES
YES
No sound comes out. (1)
No sound comes out at UHF/VHF reception. Is the SIF output from the tuner as specified?(TU1
101_Pin7)
Are the audio outputs (A-OUT_L/R) from pins (28) and (29) of IC2702 as specified? Is the audio input from pins (28) and (29) of IC2702 to pins (1
1) and (15) of IC2502 (STEREO
AMP) normal? Is the audio output from IC2502 normal? Is the speaker switching relay (R
Y2501) normal?
YES
Check the connector (SP_P2501) of
A
V_UNIT
and
periphery of speaker
.
Are the audio signals from pins (34) and (33) (SC2_OUTL/R) of IC2501 to pins (32) and (33) of IC2702 (DIR) as specified? Is the input signal to pin (67) (SOUNDIF1) of IC2501 (MUL
TI_SOUND_PROCESSOR) as
specified?
Check tuner and its peripheral circuits.
No external input sound comes out. Are the audio signals inputted to pins (56) (L-ch) and (57) (R-ch) of IC2501? Is the L-ch audio signal outputted to pin (15) of IC3805? Is the R-ch audio signal outputted to pin (1
1) of IC3805?
<INPUT
-1>
Is the L-ch audio signal inputted from pin (5) of input terminal J1
101 to pin (13) of IC3805?
Is the R-ch audio signal inputted from pin (2) of input terminal J1
101 to pin (9) of IC3805?
<INPUT
-2>
Is the L-ch audio signal inputted from pin (6) of input terminal J1
101 to pin (3) of IC3805?
Is the R-ch audio signal inputted from pin (3) of input terminal J1
101 to pin (7) of IC3805?
<INPUT
-3>
Is the L-ch audio signal inputted from pin (5) of input terminal J1
106 to pin (1) of IC3805?
Is the R-ch audio signal inputted from pin (2) of input terminal J1
106 to pin (6) of IC3805?
<INPUT
-4>
Is the L-ch audio signal inputted from pin (2) of input terminal J1900 to pin (5) of IC3805? Is the R-ch audio signal inputted from pin (3) of input terminal J1900 to pin (8) of IC3805? <INPUT
-5>
Is the digital audio signal (HDMI_SPDIF) inputted from pin (29) of IC1912 to pin (43) of IC2702?
Check the peripheral circuits of filter circuits (Q1
145, Q1
105-6).
Check IC2702 and its peripheral circuits. Check IC2502 and its peripheral circuits. Check circuits from pins (28) and (29) of IC2702 to pins (1
1) and (15) of IC2502. (MUTE circuit:
Q2515-7) Are signals LRCK, BICK, SDT
O and SDTI
inputted/outputted from IC2702 to IC2700 (DSP) normally? Check the lines from pins (34) and (33) (SC2_OUTL/R) of IC2501 to pins (32) and (33) of IC2702.
NO NO
YES YES
No audio output when receiving digital broadcasting Is audio signal supplied to pins (53) and (54) (SC2_IN_L/R) of IC2501? Is analog audio signal supplied from the digital unit to pins (1
1) and (9) of
A
V_UNIT
connector (DA,
P1
105)?
Check the digital unit. Check between P1
105 and IC2501.