Sharp LC-45GD5U - Page 49

49
LC-45GD5U
TROUBLE SHOOTING TABLE (Continued)
<Component video signal> input No video output (3)
NO
No video output from external input <<INPUT-1>>
Is INPUT-1 selected in the input switching menu
screen?
When it cannot be selected since the characters
INPUT-1 on the menu screen are gray.
When it cannot be selected since the characters
INPUT-1 on the menu screen are gray.
Is the detection function of component video
signal normal? Check from pin 11 of J1107 to pin
38 of IC3800 (AV SWITCH) and to pin 78 of
IC2501 (MULTI_SOUND_ PROCESSOR).
YES
NO
Are component video signals supplied to pins 21
(Y), 23 (PB) and 25 (PR) of IC3800 (AV
SWITCH)?
YES
Check between J1107 and each input pin of
IC3801.
Are Y, PB and PR signals sent to pins 60, 59 and 58 of IC3800 respectively?
NO
No video output from external input <<INPUT-2>>
Is INPUT-2 selected in the input switching menu
screen?
When it cannot be selected since the characters
INPUT-2 on the menu screen are gray.
Select INPUT-2 and the input signal in the input
switching menu screen.
Is the detection function of component video
signal normal? Check between pin 10 of J1107
and pin 40 of IC3800 (AV SWITCH).
YES
YES
NO
NO
Are component video signals supplied to pins 27
(Y), 29 (PB) and 31 (PR) of IC3800 (AV
SWITCH)?
Check between J1107 and each input pin of
IC3801.
Check IC3800 and its peripheral circuits.
YES
Is Y signal supplied to pin 1 of IC3807 (MULTI_PLEXER)?
Is Cb signal supplied to pin 5 of IC3807 (MULTI_PLEXER)?
Is Cr signal supplied to pin 3 of IC3807 (MULTI_PLEXER)?
NO
Check between IC3800 and IC3807.
(Q3807, Q3806, Q3805, etc.)
YES
Is Y signal sent to pin 20 of IC3807 (MULTI_PLEXER)?
Is Cb signal sent to pin 18 of IC3807 (MULTI_PLEXER)?
Is Cr signal sent to pin 16 of IC3807 (MULTI_PLEXER)?
NO
Are control signals supplied to pins 3 and 22 of
IC3807?
YES
Is Y signal sent to pin 22 of AV_UNIT connector (PB_P5404)?
Is Cb signal sent to pin 20 of AV_UNIT connector (PB_P5404)?
Is Cr signal sent to pin 18 of AV_UNIT connector (PB_P5404)?
NO
Check between IC3807 and P5404.
(Q3803, Q3808, Q3802, Q3809, Q3801, Q3810,
etc.)
YES
Is Y signal supplied to pin 6 of IC3700 (ADC)?
Is Cb signal supplied to pin 2 of IC3700 (ADC)?
Is Cr signal supplied to pin 14 of IC3700 (ADC)?
NO
Check Y signal between pins 24 and 25 of IC3702 and pin 6 of IC3700.
Check Cb signal between pins 20 and 21 of IC3702 and pin 2 of IC3700.
Check Cr signal between pins 16 and 17 of IC3702 and pin 14 of IC3700.
YES
Are digital video signals sent from output terminals of IC3700?
NO
Check IC3700 and its peripheral circuits.
YES
Is Y signal supplied to pin 8 of IC3702 (L.P.F)?
Is Cb signal supplied to pin 11 of IC3702 (L.P.F)?
Is Cr signal supplied to pin 13 of IC3702 (L.P.F)?
NO
Check between connector PB and IC3702.
YES
Is Y signal supplied to pin 22 of MAIN_UNIT connector (PB_CN1800)?
Is Cb signal supplied to pin 20 of MAIN_UNIT connector (PB_CN1800)?
Is Cr signal supplied to pin 18 of MAIN_UNIT connector (PB_CN1800)?
NO
Check B to B "PB".