Sharp DV-NC55S Service Manual page 44

FLOW CHART NO.7
No power is turned on.
Does power control(H) signal at pin(94) of IC701
change from "L" to "H" level?
YES
Does the base voltage of RJ9904 change from
about 12.6V to 11.8V?
YES
Is voltage of 12V sent out from the emitter of
RJ9904 transistor?
YES
Does the base voltage of Q9903 change from
about 5.5V to 6.2V?
YES
Is voltage of 5V sent out from the emitter of Q9903
transistor?
YES
Check peripheral circuit for poor soldering.
FLOW CHART NO.8
The capstan motor fails to run.
Is the voltage more than about 2.6V DC given out
of pin(59) of IC701.
YES
Is the supply voltage of 5V feed to pin(8) of AC
connector?
YES
Is the voltage more than 2.6V DC sent in pin(4) of
AC connector?
YES
Is approx. 3.5V applied to the pin(3) of the AC
connector?
YES
Is 23V applied to the pin(5) of the AC connector
normally?
YES
Replace capstan motor.
NO
Check IC701.
NO
Check line between RJ9904, Q9905 and IC701.
NO
Check peripheral circuit of RJ9904 and AT 12V line.
NO
Check line between emitter of RJ9904 and base of
Q9903.
NO
Check peripheral circuit of Q9903 and AT 5V line.
NO
Check IC701.
NO
Check PC 5V line.
NO Check between the pin(4) of AC connector and all
the way up thru to pin(59) of IC701.
NO
Check the pin(60) of IC701.
NO
Check AT 23V line.
FLOW CHART NO.9
The drum motor fails to run.
Is the voltage more than about 2.6V DC given out
of pin(58) of IC701.
YES
Is the supply voltage of 5V feed to pin(3) of IC7002?
YES
Is the voltage more than about 2.6V applied at
pin(2) of IC7002?
YES
Is the supply voltage of 12V feed to pin(21) of IC7002?
YES
Check or replace drum motor.
FLOW CHART NO.10
The drum motor runs only for a few seconds.
Is drum PG signal given out of pin(7) of IC7002?
YES
Is drum PG signal given out of pin(66) of IC701?
YES
Is V-H.SW.P pulse given out of pin(23) of IC701?
YES
Replace IC701.
FLOW CHART NO.11
No head switching pulse.
Is the drum motor rotating?
YES
Is the drum PG signal and drum FG signal present
on pins(66) and (65) of IC701, respectively?
YES
Are the drum PG and drum FG signals present on
pins(7) and (8) of IC7002?
YES
Check periperal circuit of IC7002.
NO
Check IC1701.
NO
Check PC 5V line.
NO Check between pin(58) of IC701 and all the way
up to pin(2) of IC7002.
NO
Check PC 12V line.
NO
Check pins(4), (5), (6) of IC7002 and periperal circuits.
YES
Check or replace drum motor.
NO
Check line between pin(7) of IC7002 and all the
way up thru to pin(66) of IC701.
NO
Check IC701.
NO
See FLOW CHART NO.9, 10
<The drum motor fails to run>
<The drum motor runs only for a few seconds>
NO
Replace IC701.
D-FG D-PG
About 5Vp-p About 5Vp-p
NO Check line between pins(7), (8) of IC7002 and all
the way up thru to pins(65), (66) of IC701.