Sharp Aquos LC-42BX5H, Service Manual

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LC-42BX5H/M/X
6 – 12
No picture appears on the SUB side of the two-screen display.
No picture from Video or S-Video appears.
YES
Are waveforms of pins 27 (Video), 19 (S_Y) and 11 (S_C) of
IC8401 normal? NO Check if the routes from pins 23 (Video), 27 (S_Y) and 25 (S_C)
of IC3401 to pins 27 (Video), 19 (S_Y) and 11 (S_C) of IC8401
are normal.
YES
Are waveforms of output DE/HSO/VSO of IC8401 and each data
(R/G/B0-9) normal? NO Check IC8401 and its peripheral circuits.
No picture appears on the SUB side of the two-screen display.
No picture from Component appears.
YES
Is input waveform of IC3404 normal?
INPUT1: pin 27 (Y), pin 3 (Pb), pin 7 (Pr)
INPUT2: pin 25 (Y), pin 1 (Pb), pin 5 (Pr) NO Check circuits to IC3401 input.
YES
Are waveforms of pins 30 (Sync), 25 (Y), 17 (Pb) and 9 (Pr) of
IC8401 normal? NO Check peripheral circuits of IC3401 and if the routes from pins 17
(Y), 14 (Pb) and 11(Pr) of IC3401 to pins 30 (Sync), 25 (Y), 17
(Pb) and 9 (Pr) of IC8401 are normal.
YES
Are waveforms of output DE/HSO/VSO of IC8401 and each data
(R/G/B0-9) normal? NO Check IC8401 and its peripheral circuits.