Sharp vc-ga56z Service Manual page 40

FLOW CHART NO.13
The drum motor fails to run.
Is the voltage more than about 2.6V
NO
DC given out of pin(46) of IC701?
YES
NO
Is the supply voltage of 5V feed to
pin(3) of IC706?
YES
NO
Is the voltage more than about 2.6V
applied at pin(2) of IC706?
YES
NO
Is the supply voltage of 12V feed to
pin(21) of IC706?
YES
Check or replace drum motor.
FLOW CHART NO.14
The drum motor runs only for a few seconds.
Is drum PG signal given out of
NO
pin(7) of IC706?
YES
NO
Is drum PG signal given out of
pin(66) of IC701?
YES
Is V-H.SW.P pulse given out of
NO
pin(23) of IC701?
YES
Replace IC701.
Check IC701.
Check PC 5V line.
Check between pin(46) of IC701
and all the way up to pin(2) of
IC706.
Check AT 12V line.
Replace IC706.
NO
Check pins (4), (5), (6) of IC706 and
periperal circuits.
YES
Check or replace drum motor.
Check line between pin(7) of IC706
and all the way up thru to
pin(66) of IC701.
Check IC701.
FLOW CHART NO.15
No head switching pulse.
NO
Is the drum motor rotating?
YES
Is the drum PG signal and drum FG
NO
signal present on pins(66) and (65)
of IC701, respectively?
YES
Are the drum PG and drum FG
YES
signals present on pins(7) and (8) of
IC706?
NO
Check peripheral circuit of IC706.
See FLOW CHART NO.13,14.
Are there drum PG M.M.signal at
pin(81) of IC701?
YES
NO
Check C723 and readjust R701
(HEAD SW. POINT control.)
Replace IC701.
Could be lines between IC706
and IC701.