Sharp LC-26D43U Service Manual page 28

LC-26D43U
TROUBLESHOOTING TABLE
Is SIF output from the tuner (TU1101_Pin15) normal?
Yes
Is input signal fed to pin21 (SOUNDIF 1)of IC1401(SIF
Demodulator) normal?
Yes
Are audio signals from pins 29 and 30 (SC2_OUTL/R) of
IC1401 to pins 51 and 52 of IC1404 (CODEC) normal?
Yes
Are audio outputs (A-OUT_L/R) of pins 38 and 39 of
IC1404 normal?
Yes
Is audio input from pins 38 and 39 of IC1404 to pin 3 and 5
of IC2701 (STEREO_AMP) normal?
Yes
Is audio output from IC2701 normal?
Yes
Check the connector (P2703) of AV_UNIT and around the
speakers.
Is monitor audio output set to "Variable"?
No
Are audio output pins 40 and 41 of IC1404 (CODEC)
normal?
Yes
Are audio output pins 7 and 1 of IC1408 (Buffer_AMP)
normal?
Yes
Check between IC1408 and MONITOR OUTPUT terminal
(J501,J502).
No audio output during UHF/VHF reception
No
Check the tuner and peripheral circuits.
No
Check the filter circuits (Q1102-3) and peripheral
circuits
No
Check between pins 29 and 30 (SC2_OUTL/R) of
IC1401 and pins 51 and 52 of IC1404(CODEC)
Are the DSP_LRCK,DSP_BCKIN,DSP_SDIN1,
No
DSP_MCLK,DSP_SDOUT1,DSP_SDOUT2 signals
sent from IC1404 to IC1407(DSP) normally?
Check IC1404 and peripheral circuits.
No
Check the circuits between pins 38 and 39 of
IC1404 and pins 3 and 5 of IC2701. (MUTE
cercuits:Q1307,Q1314,Q1313)
No
Check IC2701 and peripheral circuits
No monitor audio output
Yes
Reset monitor audio output to "Fixed".
No
Check IC1404 and peripheral circuits.
No
Check IC1408 and peripheral circuits.
28
(Continued)
Yes