Sharp VC-M313 (serv.man9) Service Manual ▷ View online
42
FLOW CHART NO.16 DRUM SERVO TROUBLESHOOTING
Drum servo does not function.
Check peripheral circuit of X703.
Is there 14.318MHz oscillation at
pins(37) and (38) of IC701?
NO
In PB mode
YES
In REC mode
Is there drum FG signal at pin(85)
of IC701 present?
Is the V-SYNC signal(reference) at
pin(50) of IC701?
YES
NO
NO
Check peripheral circuit of pin(50) of
IC701, C746, C747 and R745.
Check drum FG signal line.
Is the head switching pulse at pin(23)
of IC701 present?
NO
See FLOW CHART NO.15
(HEAD SWITCHING PULSE
TROUBLESHOOTING.)
YES
YES
Is the drum APC output at pin(34) of
IC701 and drum AFC output at
pin(32) of IC701 present?
NO
Replace IC701.
YES
YES
Is the drum control voltage applied
to pin(29) of IC702?
YES
Is pin(58) of IC701 in high
impedance?
NO
YES
NO
Check line between pins(34) and
(32) of IC701 and pin(29) of IC702.
Does the IC702 operate normally?
Replace IC701.
Replace drum motor.
43
1
2
FLOW CHART NO.17 CAPSTAN SERVO TROUBLESHOOTING
Capstan servo does not function
.
Only PB mode inoperative
YES
Only REC mode inoperative
YES
YES
NO
YES
NO
NO
NO
NO
NO
Check peripheral
circuit of pin(50) of
IC701, C746, C747
and R745.
Is there 14.318MHz
oscillation at pins
(37) and (38) of
IC701?
Check peripheral
circuit of X703.
YES
YES
Dose pin(59) of
IC701 operate
normally?
Check "1"
Check "2"
Check capstan
motor unit and/or
replace.
Is there capstan
AFC and APC
at pins(31) and (33)
of IC701?
Replace IC701.
Replace A/C head.
YES
YES
YES
NO
NO
NO
Is there capstan
AFC signal at pin
(31) of IC701?
NO
NO
NO
Is there capstan
APC signal at pin
(33) of IC701?
YES
NO
Replace IC701.
Does PB CTL
signal appear at
pin (76) of IC701?
Replace IC701.
Is there REC CTL
signal output at
pins(75) and (74)
of IC701?
Does PB CTL
signal appear at
pin(76) of IC701?
Does A/C head
operate normally?
Adjust the height
of the A/C head.
Does the capstan
FG signal appear
at pin (67) of IC-
701?
Check the capstan
FG signal line bet-
ween pin(6) of AC
connector and pin
(67) of IC701.
Check peripheral
circuit of AC
connector.
Is the V-SYNC
signal(reference) at
pin(50) of IC701?
Are REC and/or PB
mode inoperative?
44
FLOW CHART NO.18 E-E MODE TROUBLESHOOTING
No picture E-E signal.
NO
NO
NO
NO
NO
YES
YES
YES
YES
Is there picture signal inputted
in the pins(28), (30) and (31)
of IC201?
1For ext. input mode.
nCheck line between rear video input terminal and pin(30)<1-scart>
or pin(31)<2-scart> of IC201.
nCheck line front video input terminal and pin(28) of IC201.
2For U/V tuner mode.
nCheck line between video output terminal of tuner and pin(31) of
IC201.
Is the supply voltage of 5V
(Y-Vcc) fed to pin(12) of
IC201?
Check PC 5V line.
NO
Check line between pin(52) of
IC201, and pin(49) of IC701.
YES
YES
YES
Is there a picture signal
outputted in the emitter of
Q708?
Check peripheral circuit of
Q708.
NO
Check the line between Q708
and Q2801. <1-scart models>
Check the line between Q708
and IC2501. <2-scart models>
Is there Y/C serial data and
Y/C clock signal applied to
pins(63) and (62) of IC201?
Check line between pins(63),
(62) of IC201 and pins(56),
(57) of IC701.
NO
Is the supply voltage of 5V
(OSD-Vcc) fed to pin(51) of
IC701?
Replace IC201.
NO
Check PC 5V line.
Is there a picture signal
inputted in the base of
Q2801?<1-scart models>
Is there a picture signal
inputted in the pin(19) of
IC2501?<2-scart models>
YES
NO
Check peripheral circuit of
Q2801. <1-scart models>
Check peripheral circuit of
IC2501. <2-scart models>
Is there a picture signal
outputted in the emitter of
Q2801?<1-scart models>
YES
1Line output : Check the line between Q2801<1-scart models> or
IC2501<2-scart models> peripheral and output
terminal periphery.
2RF output : Check the line between Q708 peripheral and RF
video input terminal of tuner periphery.
Is there a picture signal
outputted in the pin(20) of
IC2501?<2-scart models>
Is there a picture signal
outputted in the pin(52) of
IC201?
Is there a picture signal
inputted in the pin(49) of
IC701?
Is there a picture signal
outputted in the pin(47) of
IC701?
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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