Read Sharp VC-M303 (serv.man9) Service Manual online
45
FLOW CHART NO.21 DECODER TROUBLESHOOTING
SELECT
OUTPUT
INPUT SIGNAL
OUTPUT SIGNAL
<Normal Audio Double scart>
MODE
SIG.
DECODER CIRCUIT
SIG.
FLOW
INPUT
(switch)
FLOW
(A)
Pin47 of IC701(Y/C video output)
E2(L2) video input
→
pin19
pin18
pin20
→
E1(L1) video output
21PIN CONNECTOR
(B)
→
(A)
Pin11 of IC201(Audio output)
E2 audio input
→
pin36
pin1
pin35
→
E1(L1) audio output
21PIN CONNECTOR
(B)
→
(A)
Tuner video output
E1(L1) video input
Pin47 of IC701(Y/C video output)
→
pin16
pin14
pin19
pin23
→
E2(L2) video output
21PIN CONNECTOR
(B)
→
(C)
→
(A)
Tuner audio output
E1 audio input
Pin11 of IC201(Audio output)
→
pin9
pin5
pin36
pin29
→
E2(L2) audio output
21PIN CONNECTOR
(B)
→
(C)
→
(A)
E2(L2) video input
E1(L1) video input
Tuner video output
→
pin18
pin14
pin16
pin21
→
Pin31 of IC201
Y/C video input
(Tuner/Aux. input)
(B)
→
(C)
→
(A)
E2 audio input
E1 audio input
Tuner audio output
→
pin1
pin5
pin9
pin31
→
Pin9 of IC201
(Audio input)
(B)
→
(C)
→
NO
NO
NO
YES
YES
YES
Check STBY 5V line.
Check STBY 10.5V line.
Check line between pins(25), (26)
of IC2501 and pins(17), (18) of
IC701.
Is there SDA and SCL signal
applied to pins(25) and (26) of
IC2501?
Is voltage 5V applied to the video
section power terminal at pins(15),
(17) of IC2501?
Is voltage 10.5V applied to the
audio section power terminal at
pins(8), (10) of IC2501?
Check signal line from video and
audio function logic table as shown
below.
Not output from 21pin connector in video and audio signal.
YES
YES
NO
NO
NO
NO
FLOW CHART NO.19 LINEAR SOUND MODE TROUBLESHOOTING(1)
Check the AUDIO MUTE (H) line
between pin(99) of IC6301 and
pin(21) of IC701.
Is there "L" level at pin(99) of IC201?
Is there a signal at pin(4) of IC201?
Replace IC201.
YES
YES
NO
Check the bias oscillation circuit
(T651,Q651,Q652) and A-ERASE
BIAS CTL line.
Check AT 12V line.
Check peripheral circuit of T651.
No linear sound recording(Hi-Fi E-E mode is possible)
Is the supply voltage of 12V fed to
pin(2) of T651?
YES
Is there a signal(Bias) at pin(5) of
T651?
Is there a signal(Bias+Audio sig.)
at pin(6) of T651?
Check the MH-AA harness and A/C
head.
YES
YES
YES
YES
NO
NO
NO
NO
NO
FLOW CHART NO.20 LINEAR SOUND MODE TROUBLESHOOTING(2)
Are the MH-AA harness and the PB
AMP peripheral parts normal?
Check the AUDIO MUTE (H) line
between pin(99) of IC6301 and
pin(21) of IC701.
Check line between pin(11) of
IC201 and pin(54) of IC6301.
For Hi-Fi models :
Is there audio signal inputted at
pin(54) of IC6301?
Except Hi-Fi models :
Check line ranging from ext. audio
output terminal.
Clean A/C head.
YES
Is azimuth height of A/C head
properly adjusted?
YES
Replace A/C head.
Readjust azimuth hight.
Replace IC201.
Is there a signal at pin(100) of IC201?
Is there "L" level at pin(99) of IC201?
Is there a signal at pin(11) of IC201?
No linear sound playback(Hi-Fi E-E mode is possible)
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