SHARP VC-7050
Service Manual

VC-6050 VC-7050 VC-H8050

NO.13 FLOW CHART NO.15
The drum motor fails to run. No head switching pulse.

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

YES

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

YES NO Check between pin(46) of IC701 Is the voltage more than about 2.6V

YES

Check C723 and readjust R724. applied at pin(2) of IC706? IC706. (HEAD SW. POINT control.) and all the way up to pin(2) of

YES Replace IC701. NO

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

IC706? Check peripheral circuit of IC706.

and IC701. YES

Check or replace drum motor.

FLOW CHART NO.14

42
Replace IC706.
NO

The drum motor runs only for a few seconds.

Is drum PG signal given out NO Check pin(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

Replace IC701.