Sharp VC-M331HM (serv.man5) Service Manual ▷ View online
41
VC-M321HM
VC-M331HM
VC-M331HM
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.
42
VC-M321HM
VC-M331HM
VC-M331HM
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?
43
VC-M321HM
VC-M331HM
VC-M331HM
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?
1
For ext. input mode.
■
Check line between rear video input terminal and pin(30)<1-scart>
or pin(31)<2-scart> of IC201.
■
Check line front video input terminal and pin(28) of IC201.
2
For U/V tuner mode.
■
Check 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
1
Line output : Check the line between Q2801<1-scart models> or
IC2501<2-scart models> peripheral and output
terminal periphery.
2
RF 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?
44
VC-M321HM
VC-M331HM
VC-M331HM
NO
NO
YES
FLOW CHART NO.19 RECORDING MODE (E-E operational) TROUBLESHOOTING
Picture(Luminance) record is impossible
(E-E mode is possible).
Is there luminance signal
(approx. 0.5Vp-p) input in the
pin (19) of IC201?
Check line between pins(18)
and (19) of IC201.
YES
NO
Is there luminance signal
(approx. 0.3Vp-p) input in the
pin (42) of IC201?
Check line between pins(21)
and (42) of IC201. (C208)
NO
YES
YES
YES
YES
Is there luminance signal
(approx. 0.5Vp-p) input in the
pin (26) of IC201?
Check line between pins(39)
and (26) of IC201. (C212)
NO
Is there luminance signal
(approx. 0.5Vp-p) input in the
pin (23) of IC201?
Check line between pins(24)
and (23) of IC201. (C210)
NO
Is there luminance signal
(approx. 0.5Vp-p) input and
output in the pins(13) and (14)
of IC201, respectively?
Check peripheral circuit of
pins (13) and (14) of IC201.
(R201, R202, C203)
Is there luminance signal
(approx. 0.5Vp-p) input in the
pin (39) of IC201?
Is voltage 5V applied to the
CCD section power terminal at
pin(36) of IC201?
YES
Is CCD control voltage approx.
5V applied normally to the pin
(37) from pin(57) of IC201?
Is clock signal (approx.
8.86MHz <PAL mode>
/0.5Vp-p) for CCD applied
normally to the pin(44) from
(69) of IC201?
NO
NO
YES
YES
YES
Is voltage of 5V applied to the
chroma power terminal pin(61)
of IC201?
Check peripheral circuit pin
(61) of IC201 and PC 5V line.
Is there chroma signal (approx.
156mVp-p <PAL mode>
/burst) input in the pin(46) of
IC201?
Check line between pin (60)
and pin(46) of IC201. (C512)
NO
NO
Is there chroma signal (approx.
197mVp-p <PAL mode>
/burst) input in the pin(58) of
IC201?
For PAL/SECAM mode. Check
whether the pins(73) and (75)
of IC201 oscillate 4.43MHz at
PAL/SECAM mode.
Check line between pins(58)
and (35) of IC201. (R505, C515)
Is there chroma signal (approx.
197mVp-p <PAL mode>
/burst) output in the pin(35) of
IC201?
YES
YES
Is CCD control voltage approx.
5V applied normally to the pin
(37) from pin(57) of IC201?
Is clock signal (approx.
8.86MHz <PAL mode>
/0.5Vp-p) for CCD applied
normally to the pin(44)
from (69) of IC201?
YES
Is voltage 5V applied to the
CCD section power terminal at
pin(36) of IC201?
NO
Although picture record is possible, colour does
not appear in PAL mode (E-E mode is possible).
YES
Replace IC201.
YES
Check or replace the cylinder.
NO
Is the supply voltage of 5V
(PRE/REC Vcc) fed to pin(90)
of IC201?
SP mode : Is there record FM signal (approx. 20mVp-p) output in the pins
(88), (89) <SP1> and pins(86), (87) <SP2> of IC201?
EP mode : Is there record FM signal (approx. 20mVp-p) output in the pins
(93), (94) <EP1> and pins(92), (91) <EP2> of IC201?
SP mode : Is there chroma ingredient included signal (approx. 20mVp-p) output in the pins(88), (89) <SP1>
and pins(86), (87) <SP2> of IC201?
EP mode : Is there chroma ingredient included signal (approx. 20mVp-p) output in the pins(93), (94) <EP1>
and pins(92), (91) <EP2> of IC201?
NO
For PAL/SECAM mode.
Check parts around of X501.
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