Sharp LC46D43U - Aquos - 720p LCD HDTV Service Manual page 27

No audio output from external input
<<HDMI>> [INPUT-4/INPUT5 (Digital audio mode)]
Is digital audio signal (DTV_SPDIF) fed from pin E12 of IC8101 to pin 4 of IC1404?
<<HDMI>> [INPUT-5 (Analog audio mode)]
Is L-ch audio signal fed from pin 3 of input terminal J1501 to pin 57 of IC1404?
Is R-ch audio signal fed from pin 2 of input terminal J1501 to pin 58 of IC1404?
PCINPUT<<INPUT-6>>
Is L-ch audio signal fed from pin 2 of input terminal J1502 to pin 55 of IC1404?
Is R-ch audio signal fed from pin3 of input terminal J1502 to pin 56 of IC1404?
<<INPUT-1>>
Is L-ch audio signal fed from input terminal J501 to pin 12 of IC1405?
Is R-ch audio signal fed from input terminal J501 to pin 1 of IC1405?
<<INPUT-2>>
Is L-ch audio signal fed from input terminal J502 to pin 14 of IC1405?
Is R-ch audio signal fed from input terminal J502 to pin 5 of IC1405?
Is L-ch audio fed from pin 13 of IC1405 to pin 53 of IC1404?
Is R-ch audio fed from pin 3 of IC1405 to pin 54 of IC1404?
YES
No audio output during digital broadcasting reception
Are the I2S signals DAKCK, SCLK, LRCK, and
DATAOUT sent from pins B22, F13, E13 and F12 of
IC8101 normally?
Are input signals of pins 24 (DAKCK), 11 (SCLK), 10
(LRCK), 32 (DATA) of IC1404 normal?
Are audio signals from pins 29 and 30 of IC1404 to pins 27 and
25 of IC1407 (DSP) normal?
Are audio outputs pins 38 and 39 of IC1404 normal?
Is audio input from pins 38 and 39 of IC1404 to pins 3 and 5 of
IC2701(STEREO_AMP) normal?
Is audio output from IC2701 normal?
Check the connector (P2703) of TERMINAL_UNIT and around
the speakers.
YES
YES
YES
YES
YES
YES
<<INPUT-3>>
Is L-ch audio signal fed from input terminal J501 to pin 15 of IC1405?
Is R-ch audio signal fed from input terminal J501 to pin 2 of IC1405?
Check around IC8101 BCM3551.
NO
NO Check the circuits between pins B22, F13, E13 and F12 of IC8101
and pins 24, 11, 10 and 32 of IC1404.
NO Check between pins 29 and 30 of IC1404 and pins 27 and 25 of
IC1407 (DSP).
NO Are the LRCK, BICK, SDTO and SDTI signals sent from IC1404 to
IC1407 (DSP) normally?
Check IC1403 and peripheral circuits.
NO Check the circuits between pins 38 and 39 of IC1404 and pins 3 and
5 of IC2701. (MUTE circuits: Q1307, Q1313, Q1314, Q1404)
NO Check IC2701 and peripheral circuits.
4 – 2
LC-42D43U
YES