Read Sharp VC-M305HM (serv.man9) Service Manual online
41
VC-M305HM/LM
VC-M315HM/LM
YES
YES
YES
NO
NO
NO
FLOW CHART NO.11 SYSTEM CONTROL TROUBLESHOOTING
No power is turned on.
Does power control (H) signal at
pin(96) of IC701 change from "L" to
"H" level?
"H" level?
Check IC701.
Does the base voltage of Q966
change from about 12.6V to 11.8V?
change from about 12.6V to 11.8V?
Check line between Q966, Q967 and
IC701.
IC701.
Is voltage of 12V sent out from the
collector of Q966 transistor?
collector of Q966 transistor?
Check peripheral circuit of or Q966
and AT 12V line.
and AT 12V line.
YES
YES
YES
NO
NO
Does the base voltage of Q961
change from about 5.5V to 6.2V?
Check line between emitter of or Q966
and base of Q961.
and base of Q961.
Is voltage of 5V sent out from the
emitter of Q961 transistor?
emitter of Q961 transistor?
Check peripheral circuit of Q961 and
AT 5V line.
AT 5V line.
Check peripheral circuit for poor
soldering.
soldering.
NO
NO
NO
FLOW CHART NO.9 CASSETTE CONTROL TROUBLESHOOTING(2)
A cassette tape is taken in, but ejected at once.
Does the start sensor pulse at pin(87)
of IC701 change from "L" to "H" level
when the cassette tape is loaded?
of IC701 change from "L" to "H" level
when the cassette tape is loaded?
Check line between start sensor
and pin(87) of IC701.
and pin(87) of IC701.
Does the end sensor pulse at pin(86)
of IC701 change from "L" to "H" level
when the cassette tape is loaded?
of IC701 change from "L" to "H" level
when the cassette tape is loaded?
Check line between end sensor
and pin(86) of IC701.
and pin(86) of IC701.
Does the master cam mode
shifter operate normally when the
cassette tape is loaded?
shifter operate normally when the
cassette tape is loaded?
Check line between cam switch
and IC701.
and IC701.
Replace IC701.
YES
YES
YES
FLOW CHART NO.10 LOADING MOTOR AND EJECT TROUBLESHOOTING
The cassette tape fails to come out.
Does the capstan motor start when
the EJECT button is pressed?
the EJECT button is pressed?
See FLOW CHART NO.12
CAPSTAN MOTOR TROUBLE-
SHOOTING
CAPSTAN MOTOR TROUBLE-
SHOOTING
Does the take-up reel disk turn
when the capstan motor is running?
when the capstan motor is running?
Check line between take-up reel
sensor and pin(2) of IC701.
sensor and pin(2) of IC701.
Is a "H" level applied at pin(10)
of P701 when a reel pulse has
been inputted?
of P701 when a reel pulse has
been inputted?
Check line between pin(92) of
IC701 and pin(10) of P701.
IC701 and pin(10) of P701.
Is the supply voltage of 12V fed
to pin(8) of P701?
to pin(8) of P701?
Is the voltage about 10V sent out
from IC on mechanism?
from IC on mechanism?
Check IC on mechanism.
Is the specified voltage applied at
the loading motor terminal?
the loading motor terminal?
Check line between IC on mechanism
and loading motor.
and loading motor.
Does the loading motor run?
Replace cassette cam, gear, etc.
YES
YES
YES
Check M 12V lines.
NO
YES
NO
YES
YES
YES
NO
NO
NO
NO
NO
Replace loading motor.
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