Sharp LC-60E77UN Service Manual page 56

LC-60E77UN/LC-65E77UM/LC-C6077UN/LC-C6577UM
INPUT-1 No audio.
Is INPUT-1 selected on the input select menu screen?
NO
Refer to ": No external input video [INPUT-1]".
YES
Is the audio output selected for "VARIABLE" on the menu screen?
NO
Set the audio output to "FIXED".
YES
Does the audio signal come from pins (5) (L) and (3) (R) of input
terminal (J507) to pins (V30)(L) and (V29) (R) of IC8001 (CPU)?
NO
Check the line between J507 and IC8001.
YES
Does the audio signal come from pins (N29/N30) (PGA0OUT_L/R) of IC8001 (CPU) to pins (4/7)
(INLP/INRP) of IC2701 (AMP)?
NO
Check the line between IC8001 and IC2701,
and their peripheral circuits (Q1306,
AMP_MUTE line, etc.).
YES
Is the audio output from IC2701 as specified?
YES
Check the connector (P2701), speakers and their peripheral cir-
cuits.
No audio (1)-1
Is INPUT-2 selected on the input select menu screen?
YES
Is the audio output selected for "VARIABLE" on the menu screen?
YES
Does the audio signal come from pins (2) (L) and (4) (R) of input
terminal (J503) to pins (U29) (L) and (U28) (R) of IC8001 (CPU)?
YES
NO Check IC2701 and its peripheral circuits.
6 – 8
INPUT-2 No audio.
NO
Refer to ": No external input video [INPUT-2]".
NO
Set the audio output to "FIXED".
NO
Check the line between J503 and IC8001.