SHARP VCA50
Service Manual

NO.13 TROUBLESHOOTING(1) FLOW CHART NO.14 DRUM MOTOR TROUBLESHOOTING(2)

The drum motor fails to run. The drum motor runs only for a few seconds.

Replace IC706.

VC-A10/A10S/A500 VC-A50/A50S/A50SB VC-A60/A75/A80S

Is the voltage more than about 2.6V NO DC given out pin(25) of IC701?
Is drum PG signal given out from the NO Check peripheral circuit of pins (22), (23) pin (33) IC706? and (24) of IC706.

Check IC701. NO

YES

Is the voltage more than about 2.6V Check line between pin(25) of IC701

NO YES DC given out and pin(12) (sankyo IC) of AC YES

of AC (kumaconnector or pin(32) (kumagaya IC) Check drum motor. gaya IC) IC706? of IC706.
Is drum PG signal fed to pin(47) of

Is the supply voltage 12V fed to NO IC701? and pin(47) of IC701. Check M 12V line. pin(8) (sankyo IC) of AC connector or pin(20) (kumagaya IC) of IC706? YES
NO YES Is head switching pulse sent out from

YES NO Check line between pin(33) of IC706

the pin(18) of IC701? Replace drum motor.
YES

Check IC701.

Replace IC701.

40
FLOW CHART NO.15 HEAD SWITCHING PULSE TROUBLESHOOTING.
Is the drum motor rotating? NO
YES

No head switching pulse.

See FLOW CHART NO.14, 15 (DRUM MOTOR TROUBLESHOOTING(1), (2))

Is the PG signal and drum FG YES

Replace IC701. signal present at pin(47) of IC701?
NO

D-PG 2.5V D-FG 2.5V

Check line between IC706 and IC701.
NO

Are the PG signal and drum YES FG signal present on pins (33), (34) of IC706? Check peripheral circuit of IC706.