Sharp LC-40D68UT Service Manual page 60

LC-40D68UT
No audio at UHF/VHF broadcast signal reception.
Is TV selected on the input select menu screen?
Refer to "No video at UHF/VHF broadcast signal
reception".
YES
Is the audio output selected for "VARIABLE" on the menu screen?
Set the audio output to "FIXED".
YES
Is there the SIF signal output at pin (16) of tuner (TU1101)?
Is there the AFT signal output at pin (17) of tuner (TU1101)?
Check the Tuner I2C lines.
1) TU1101: pin (8) (TUN_SDA_C5), pin (9)
(TUN_SCL_C5)
2) SC1101/SC1201: pin (16), pin (15)
3) IC8001: pin (F2), pin (E1)
Check TU1101 and its peripheral circuits.
YES
Does the SIF signal come from pin (16) of tuner (TU1101) to pin
(D5) of IC8001 (CPU)?
Does the AFT signal come from pin (17) of tuner (TU1101) to pin
(W22) of IC8001 (CPU)?
Check the line between TU1101 and IC8001, and their
peripheral circuits (Q1101, Q1102, etc.).
1) TU1101: pin (16) (SIF), pin (17) (AFT_OUT)
2) SC1101/SC1201: pin (8), pin (12)
3) IC8001: pin (D5), pin (W22)
YES
Does the audio signal come from pins (C4/A3) (SPOUT_L/R) of IC8001 (CPU) to
pins (3) (INLP), and (7) (INRP) of IC2701 (AMP)?
YES
Is the audio output from IC2701 as specified?
YES
Check the connector (P2701), speakers and their peripheral circuits.
No audio (4)
NO
NO
NO
NO
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No audio at digital broadcast signal reception.
Is TV selected on the input select menu screen?
Refer to "No video at digital broadcast signal reception".
YES
If no video appears, refer to "No video at digital broadcast signal recep-
tion".
Is the audio output selected for "VARIABLE" on the menu screen?
Set the audio output to "FIXED".
YES
NO Check the line between IC8001 and IC2701, and
their peripheral circuits (Q1306/Q1307,
AMP_MUTE line, etc.).
NO Check IC2701 and its peripheral circuits.
NO
NO