SHARP VC-GA56Z
Service Manual

FLOW CHART NO.16
Drum servo does not function.

Is there 14.318MHz oscillation at pins(37) and (38) of IC701?
YES In PB mode NO

NO

Check peripheral circuit of X701.

In REC mode YES

Is there drum FG signal at pin(65) of IC701?
YES

Is there V-SYNC signal(reference) at pin(50) of IC701?
NO

Check drum FG signal line.

Is there head switching pulse at pin(23) of IC701?
YES

NO

See FLOW CHART NO.15.

Check pin(50) of IC701, C770, C771, R770 and their peripheral circuits.

Are there drum APC output at pin(34) NO of IC701 and drum AFC output at pin(32) of IC701?
YES

Replace IC701.

Is there drum control voltage input at pin(2) of IC706?
YES

NO

Check line between pins(34) and (32) of IC701 and pin(2) of IC706.
YES

41
Does the IC706 operate normally?
YES

Is pin(46) of IC701 in high impedance?

NO

Replace IC701.

Replace drum motor.

VC-GA56Z VC-GH96Z