Sharp 13VT-L200 Service Manual page 45

SYSTEM CONTROL TROUBLESHOOTING
No power.
Are serial clock pulse and TV
NO
data pulse applied to pins (67)
and (66) of IC7701 from IC2001?
YES
Are system control data pulse
NO
and system control ready pulse
applied to pins (36) and (35) of
IC2001 from IC7701?
YES
Does power control (H) signal at
NO
pin (21) of IC7701 change from
"L" to"H" level?
YES
NO
Is the PC9V line normal?
YES
NO
Is the PC5V line normal?
YES
Check peripheral circuit for poor
soldering of PC9V and PC5V
lines.
FLOW CHART NO.1-5
Is 5V at pin (8) of AC connector?
Check IC2001 and IC7701.
Is the voltage more than about
2.6V given to pin (4) of AC
connector?
Is the voltage at pin (3) of AC
connector 1.8~2.7V?
Check IC7701.
Check IC765 (PC9V GEN.)
Check/replace the capstan motor.
Check Q756 (PC5V GEN.)
CAPSTAN MOTOR TROUBLESHOOTING
The capstan motor fails to run.
NO
YES
NO
YES
NO
YES
NO
Is 8V or 12V at pin (5) of AC
connector?
YES
FLOW CHART NO.1-6
Check the AT5V line.
Check between the MC
connector and IC7701, and
between the MC connector and
pin (75) of IC7701.
Check pin (74) of IC7701
Check the AT8V line or the
AT12V line.