Sharp DV-740 (serv.man17) Service Manual ▷ View online
9
DV-740H/S(Y,F,S,R)
Picture does not operate normally.
Set the disc on the disc tray.
Are the video signals outputted to the pins
of video encoder chip U11?
U11 32PIN CVBS
U11 27PIN S-Y/YUV-Y
U11 26PIN S-C/YUV-Cr
U11 31PIN YUV/Cb
Is the setup menu “TV OUTPUT” set
correct?
YES
YES
Set it correct.
NO
NO
Check other pin of
U11.
Make sure
Pin38-42, 2-4;
Pin23 SCLOCK,
Pin24 SDATA,
Pin44 CLOCK
work normally.
Replace U11.
YES
NO
Check U1.
Are the video signals outputted to each
emitter of the Q12, Q17, Q18, and Q19?
Q12, Q17, Q18, Q19 is video buffer.
Q12: YUV-Y/S-Y
Q18: YUV-Cr/S-C
Q17: YUV-Cb
Q19: CVBS
Check the each buffer
and each filter.
NO
YES
Are the video signals outputted to the
specific output terminal?
Are the composite video signals outputted
to the Video Out terminal (Pin1 of P5)?
Are the Y/C signals outputted to the
S-Video out terminal (Pin5, 3 of P5)?
Are the YUV signals outputted to the YUV
Out terminal (Pin1, 2,3 of P5)?
YES
Check the connect circuit from
Q19 to P5.
Check the connect circuit from
Q12 and Q18 to P5.
Check the connect circuit from
Q12 and Q17 and Q18 to P4.
NO
NO
NO
DV-740H/S(Y,F,S,R)
10
Sound does not operate normally.
Set the disc on the disc tray.
Are the digital signals inputted to the
pins of audio D/A convert U12?
U12 PIN2 SDATA
U12 PIN3 SCLK
U12 PIN4 LRCK
U12 PIN5 MCLK
Is the setup menu “AUDIO OUTPUT” set
correct?
YES
YES
Set it correct.
NO
NO
Replace U12.
YES
Check U1.
Are the analog audio signals outputted to
the amplifiers?
U12 PIN12 AOUTL
U12 PIN16 AOUTR
Make sure the mute
pin is “L” level.
U12 PIN16 MUTEC
NO
YES
Are the L/R analog audio signals outputted
to the specific output terminal?
P3 2PIN LEFT OUT
P3 3PIN RIGHT OUT
YES
Check the audio amplifiers
U16 and peripheral circuit
and make sure it works
normally.
NO
Check U1.
NO
Check the audio mute circuit
works normally.
YES
NO
Check
the
connect
circuit.
11
DV-740H/S(Y,S,F,R)
8. NORMAL WAVEFORM
DV-740H/S(Y,S,F,R)
12
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