
VC-A598U/H995U/H996U
-H997U/H9977U/H998U
44
FLOW CHART NO.16
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, C770, C771 and R770.
Check drum FG signal line.
Is the head switching pulse at pin(23)
of IC701 present?
NO
See
FLOW CHART NO.15
.
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 IC706?
YES
Is pin(46) of IC701 in high
impedance?
NO
YES
NO
Check line between pins(34) and
(32) of IC701 and pin(2) of IC706.
Does the IC706 operate normally?
Replace IC701.
Replace drum motor.
Summary of Contents for VC-A598U
Page 6: ...VC A598U H995U H996U H997U H9977U H998U 6 1 3 LOCATION OF MAJOR COMPONENTS AND CONTROL ...
Page 51: ...VC A598U H995U H996U H997U H9977U H998U 51 8 BLOCK DIAGRAM POWER CIRCUIT BLOCK DIAGRAM ...
Page 52: ...VC A598U H995U H996U H997U H9977U H998U 52 SYSTEM SERVO BLOCK DIAGRAM ...
Page 53: ...VC A598U H995U H996U H997U H9977U H998U 53 ...
Page 54: ...VC A598U H995U H996U H997U H9977U H998U 54 SIGNAL FLOW BLOCK DIAGRAM VC A598U ...
Page 61: ...VC A598U H995U H996U H997U H9977U H998U 61 13 12 11 10 9 8 7 ...
Page 65: ...VC A598U H995U H996U H997U H9977U H998U 65 13 12 11 10 9 8 7 ...
Page 67: ...VC A598U H995U H996U H997U H9977U H998U 67 13 12 11 10 9 8 7 ...
Page 69: ...VC A598U H995U H996U H997U H9977U H998U 69 13 12 11 10 9 8 7 ...
Page 72: ...VC A598U H995U H996U H997U H9977U H998U 72 7 6 5 4 3 2 1 A B C D E F G H MAIN PWB ...
Page 73: ...VC A598U H995U H996U H997U H9977U H998U 73 13 12 11 10 9 8 7 ...