44
VC-A422U
VC-H822U
1
2
FLOW CHART NO.16
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, C715, C716
and R708.
Is there a 14.318
MHz
oscillation at
pins (37) and (38)
of IC701?
Check peripheral
circuit of X701.
YES
YES
Does pin(29) of
IC701 operate
normally?
Check "
1
"
Check "
2
"
Check the capstan
motor unit and/or
replace.
Is there a 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 a capstan
AFC signal at pin
(31) of IC701?
NO
NO
NO
Is there a capstan
APC signal at pin
(33) of IC701?
YES
NO
Replace IC701.
Does the PB CTL
signal appear at
pin (76) of IC701?
Replace IC701.
Is there a REC
CTL signal output
at pins(75) and
(74) of IC701?
Does the PB CTL
signal appear at
pin(76) of IC701?
Does the 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?
YES
Summary of Contents for VC-A422U
Page 51: ...VC A422U VC H822U VC A422U VC H822U 52 53 SIGNAL FLOW BLOCK DIAGRAM VC A422U ...
Page 52: ...VC A422U VC H822U VC A422U VC H822U 54 55 SIGNAL FLOW BLOCK DIAGRAM VC H822U ...
Page 53: ...56 VC A422U VC H822U POWER CIRCUIT BLOCK DIAGRAM ...
Page 63: ...72 VC A422U VC H822U M E M O ...
Page 76: ...85 VC A422U VC H822U M E M O ...