Sharp AQUOS LC-37AD1E, Service Manual

Page: 45 / 262

45
LC-37AD1E
YES
No picture comes out at the time of external input. (Pictures come out at the time of TV broadcast receiving.)
<At the time of CVBS video signal input> Is the video signal input to pin (7) of IC401 (MAIN COMB FILTER)?
Check IC1301 (AV SWITCH) and the peripheral circuitry.
No TUNER (U/V) picture comes out.
No external input picture comes out. <<INPUT1>>
Is INPUT1 selected on the input change menu screen? Select an input signal on the input signal source menu screen. Is the signal input to each input terminal of IC1301 (AV SWITCH)? <CVBS video signal input> Is the signal input to pin (1)? <Y/C video signal input> Are the Y and C signals input to pins (3) and (5), respectively? <At the time of CVBS video signal input> Are the MAIN-Y and MAIN-C signals input to pins (5) and (7) of IC801 (MAIN VIDEO CHROMA), respectively? <At the time of Y/C video signal input> Are the MAIN-Y and MAIN-C signals input to pins (44) and (43) of IC801 (MAIN VIDEO CHROMA), respectively? Are the Y, Cb and Cr MAIN signals output to pins (21), (22) and (23) of IC801? Are the Y, Cb and Cr MAIN signals input to pins (69), (68) and (67) of IC803 (RGB DECODER)? Are the R, G and B MAIN signals output to pins (35), (37) and (39) of IC803? Are the R, G and B MAIN signals input to pins (25), (1) and (5) of FL810 (30/6.7MHz L.P.F.)? Are the R, G and B MAIN signals output to TP816, TP815 and TP814?
Check PC I/F Unit
Perform checking from IC1301 to IC401.
Perform checking from IC1301 to IC1551. (Q409, Q410, Q828, etc.)
Check IC801 (MAIN VIDEO CHROMA) and the peripheral circuitry.
Are the SUB-Y and SUB-C signals input to pins (1) of IC1550 (VIDEO DRIVER) and pin (1) of IC1551 (VIDEO DRIVER), respectively?
Is the video signal (CVBS) input to pin (63) of IC1301 (AV SWITCH)? Is the signal output to the video output terminal (pin (23)) of the tuner? Is the video signal output from the tuner to TP2509? Perform checking from the video output terminal (pin (23)) of the tuner to pin (63) of IC1301 (AV SWITCH).
Are the SUB-Y and SUB-C signals output to pins (6) and (7) of IC1550 and pins (6) and (7) of IC1551, respectively?
Check IC1550, IC1551 and the peripheral circuitry.
Check the tuner and peripheral circuitry.
Check PC I/F Unit
Perform checking from IC801 to IC803. (Q842-4, IC813, IC814-6, etc.) Check IC803 (RGB DECODER) and the peripheral circuitry. Perform checking from IC803 to FL810. (Q801-3, etc.) Is pin (21) of FL810 (30/6.7MHz L.P.F.) set to "L"? Check the peripheral circuitry of FL810.
<CVBS video signal input> Perform checking from pin (20) of SC1101 to pin (1) of IC1301. <Y/C video signal input> Perform checking from pins (20) and (15) of SC1101 to pins (3) and (5) of IC1301.
<At the time of CVBS video signal input> Is the CVBS video signal output to pin (56) of IC1301?
<At the time of Y/C video signal input> Are the MAIN-Y, MAIN-C, SUB-Y and SUB-C signals output to pins (56), (58), (44) and (47
) of IC1301, respectively?
(AVC System) <<MAIN system>>
<<SUB system>> <Y/C video signal>
<At the time of CVBS video signal and Y/C video signal input>
No external input picture comes out. <<INPUT2>>
Is INPUT2 selected on the input change menu screen? Select an input signal on the input signal source menu screen. Is the signal input to each input terminal of IC1301 (AV SWITCH)? <CVBS video signal input> Is the signal input to pin (8)? <Y/C video signal input> Are the Y and C signals input to pins (10) and (12), respectively?
Perform checking from pin (20) of SC1102 to pin (8) of IC1301. Perform checking from pins (15) and (20) of SC1102 to pins (10) and (12) of IC1301.
YES
No external input picture comes out. <<INPUT3>>
Is INPUT3 selected on the input change menu screen? Select an input signal on the input signal source menu screen. Is the signal input to each input terminal of IC1301 (AV SWITCH)? <CVBS video signal input> Is the signal input to pin (15)? <Y/C video signal input> Are the Y and C signals input to pins (17) and (19), respectively?
Perform checking from pin (41) of SC1102 to pin (15) of IC1301. Perform checking from pins (36) and (41) of SC1102 to pins (17) and (19) of IC1301.
No external input picture comes out. <<INPUT4>>
Is INPUT4 selected on the input change menu screen? Select an input signal on the input signal source menu screen. Is the signal input to each input terminal of IC1301 (AV SWITCH)? <CVBS video signal input> Is the signal input to pin (22)? <Y/C video signal input> Are the Y and C signals input to pins (24) and (26), respectively?
Perform checking from pin (2) of J2404 to pin (22) of IC1301. Perform checking from pins (3) and (4) of J2401 to pins (24) and (26) of IC1301.
<At the time of CVBS video signal input> Perform checking from IC1301 to IC801.(IC401, IC403, Q827, Q401-2, Q415, etc.) <At the time of Y/C video signal input> Perform checking from IC1301 to IC801.(Q404, Q403, etc.)
YES
YES YES YES
YES YES YES YES
NO
NO
YES
NO NO
NO NO NO NO NO NO
YES YES
YES
YES
NO
NO
NO
NO
YES
YES
YES
YES NO
YES
NO
YES
NO
YES
NO
YES