SHARP VC-A312T
Service Manual

NO.13 FLOW CHART NO.15

The drum motor fails to run. No head switching pulse.

Is the voltage more than about 2.6V NO Check IC701. Is the drum motor rotating? See FLOW CHART NO.13,14. DC given out pin(46) of IC701?

YES YES

Is the supply voltage of 5V feed to Is the PG signal and drum FG NO Are there drum PG M.M.signal at pin(3) IC706? pin(81) of IC701? Check PC 5V line. signal present on pins(66) and (65) of IC701, respectively?
YES YES NO

YES

Is the voltage more than about 2.6V NO IC706.
NO

Check C723 and readjust R701 Check between pin(46) of IC701 (HEAD SW. POINT control.) applied at pin(2) of IC706? and all the way up to pin(2) of

YES Replace IC701.

Is the supply voltage of feed to Check AT 12V line. pin(21) of IC706? Are the PG and drum FG YES signals present on pins(7) and (8) of IC706?
NO

Could be lines between IC706

YES and IC701.

Check or replace drum motor. Check peripheral circuit of IC706.

41
FLOW CHART NO.14
Replace IC706.
NO

The drum motor runs only for a few seconds.

Is drum PG signal given out NO Check pins (4), (5), (6) of IC706 and pin(7) of IC706? periperal circuits.

YES

Check or replace drum motor.

Is drum PG signal given out of

pin(66) of IC701?

Check line between pin(7) of IC706 NO and all the way up thru to pin(66) of IC701.

YES

Is V-H.SW.P pulse given out of NO

Check IC701. pin(23) of IC701?

YES

VC-A312T/A315T VC-H812T/H815T

Replace IC701.