Read Sharp VC-M315HM (serv.man7) Service Manual online
44
VC-M305HM/LM
VC-M315HM/LM
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
Check peripheral
circuit of pin(50)
of IC701, C716,
C715 and R708.
circuit of pin(50)
of IC701, C716,
C715 and R708.
Is there 14.318MHz
oscillation at pins
(37) and (38) of
IC701?
oscillation at pins
(37) and (38) of
IC701?
Check peripheral
circuit of X701.
circuit of X701.
YES
YES
Dose pin(29) of
IC701 operate
normally?
IC701 operate
normally?
Check "
1
"
Check "
2
"
Check capstan
motor unit and/or
replace.
motor unit and/or
replace.
Is there capstan
AFC and APC
at pins(31) and
(33) of IC701?
AFC and APC
at pins(31) and
(33) of IC701?
Replace IC701.
Replace A/C
head.
head.
YES
YES
YES
NO
NO
NO
Is there capstan
AFC signal at pin
(31) of IC701?
AFC signal at pin
(31) of IC701?
NO
NO
NO
Is there capstan
APC signal at pin
(33) of IC701?
APC signal at pin
(33) of IC701?
YES
NO
Replace IC701.
Does PB CTL
signal appear at
pin (76) of IC701?
signal appear at
pin (76) of IC701?
Replace IC701.
Is there REC CTL
signal output at
pins(75) and (74)
of IC701?
signal output at
pins(75) and (74)
of IC701?
Does PB CTL
signal appear at
pin(76) of IC701?
signal appear at
pin(76) of IC701?
Does A/C head
operate
normally?
operate
normally?
Adjust the height
of the A/C head.
of the A/C head.
Does the capstan
FG signal appear
at pin (67) of IC-
701?
FG signal appear
at pin (67) of IC-
701?
Check the capstan
FG signal line bet-
ween pin(1) of P701
and pin(67) of IC701.
FG signal line bet-
ween pin(1) of P701
and pin(67) of IC701.
Check peripheral
circuit of P701.
circuit of P701.
Is the V-SYNC
signal(reference) at
pin(50) of IC701?
signal(reference) at
pin(50) of IC701?
Are REC and/or PB
mode inoperative?
mode inoperative?
NO
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