Sharp VC-M314 (serv.man8) Service Manual ▷ View online
45
VC-M314HM
VC-MH834HM
VC-MH834HM
FLOW CHART NO.16 DRUM SER
VO TROUBLESHOOTING
Drum servo does not function.
Check peripheral circuit of X701.
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
(65) 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 CHAR
T
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(2) of IC7002?
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
IC7002.
Does the IC7002 operate
normally?
Replace IC701.
Replace drum motor
.
46
VC-M314HM
VC-MH834HM
VC-MH834HM
1
2
FLOW CHART NO.17 CAPST
AN SER
VO TROUBLESHOOTING
Capstan servo does not function.
Only PB mode inoperative
YES
Only REC mode inoperative
YES
YES
NO
YES
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 X701.
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?
NO
47
VC-M314HM
VC-MH834HM
VC-MH834HM
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?
Check line between rear video input terminal and pin(30) and
Check line front video input terminal and pin(28) of IC201.
Is the supply voltage of 5V
(Y
-Vcc) fed to pin(12) of
IC201?
Check PC 5V line.
YES
Is there a picture signal
outputted in the emitter of
Q201?
NO
Check the line between pin
(52) of IC201 and Q201
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.
Replace IC201.
Is there a picture signal
inputted in the pin(49) of
IC701?
YES
NO
Check peripheral circuit of
Q708.
YES
Is there a picture signal
outputted in the pin(47) of
IC701?
Is there a picture signal
outputted in the pin(52) of
IC201?
See FLOW CHAR
T
NO.28 DECODER
TROUBLESHOOTING.
Is there a picture signal
outputted in the emitter of
Q708?
Check the line between pin
(52) of IC201 and pin (49)
of IC701
Is the supply voltage of 5V
(OSD Vcc) fed to pin (51)
of IC701?
NO
Check PC 5V line.
YES
Line output : Is there picture
signal inputted at pin (7) of
IC2501
NO
YES
Is there a picture signal
outputted at pins(25), (26) of
IC2501?
Check line between Q708 and IC2501.
NO
Check peripheral circuit of
IC2501.
YES
Check the line between IC2501
peripheral and output terminal
periphery.
(31) of IC201.
48
VC-M314HM
VC-MH834HM
VC-MH834HM
YES
YES
YES
YES
YES
YES
NO
NO
NO
YES
NO
NO
YES
NO
NO
NO
NO
FLOW CHART NO.19 RECORDING MODE TROUBLESHOOTING
Is there luminance signal (approx.0.5Vp-p)
inputting at pin (19) of IC201?
Is voltage 5V applied to the CCD section
power terminal at pin(36) of IC201?
Check whether the pin(73) and (75) of IC201
oscillate 4.43MHz.
Is there audio signal outputted at
pin(1
1) of IC201?
Check line between pin(60) and pin (46) of
IC201. (C512)
Check line between pin(58) and (35)
of IC201 .
Is there chroma signal inputted at
pin(58) of IC201?
SP
mode : Is there record FM signal (approx. 20mVp-p) output at pins (88), (89)(SP1)) and
pins (86), (87) ((SP2)) of IC201?:
LP
mode : Is there record FM signal (approx. 20mVp-p) output at pins (93), (94)(LP1)) and
pins (92), (91) ((LP2)) of IC201?:
Is CCD control voltage approx 0V applied
normally to the pin (37) from pin (57) of
IC201? Is the clock signal (approx.
8.86MHz/0.5Vp-p) for the CCD applied
normally to the pin(44)from (69) of IC201?
Check line between pins(24), (23) of IC201
(C210).
Check peripherial circuit of pins(13) and (14)
of IC201. (R201, R202, C203, C225)
Is there luminance signal (approx. 0.5Vp-p),
input and output at pins (13) and (14)
of IC201, respectively?
NO
NO
Check parts around of X501.
Athough picture record is possible, colour does not appear
. (E-E mode is possible.)
Is there luminance signal (approx.0.3Vp-p)
inputting at pin (42) of IC201?
YES
Is there luminance signal (approx.0.5Vp-p)
inputting at pin (26) of IC201?
Check line between pins (18) and (19)
of IC201.
Check line between pins (21) and (42)
of IC201. (C208)
Check line between pins (39) and (26)
of IC201. (C212)
Is there luminance signal (approx.0.5Vp-p)
outputting at pin (39) of IC201?
YES
Is there luminance signal (approx.0.5Vp-p)
inputting at pin (23) of IC201?
Is voltage of 5V applied to the chroma
section power terminal at pin(61) of IC201?
Check peripheral circuit pin(61) of IC201 and
PC 5V line.
Is there chroma signal inputted at pin(35) of
IC201?
SP
mode : Is there chroma ingredient included signal (approx. 20mVp-p) output at pins (88), (89)
(SP1)) and pins (86), (87) ((SP2)) of IC201?:
LP
mode : Is there chroma ingredient included signal (approx. 20mVp-p) output at pins (93), (94)
(EP1)) and pins (92), (91)((EP2)) of IC201?:
Check or replace the cylinder
.
YES
YES
Is the supply voltage of 5V(PRE/REC
Vcc) fed to pin (90) of IC201?
NO
Replace the IC201.
Picture (Luminance) record is impossible. (E-E mode is possible.)
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