Sharp 13VT-L200 Service Manual page 44

CASSETTE CONTROL TROUBLESHOOTING
A cassette tape is not taken in.
YES
Is the cassette housing distored?
NO
Does the start sensor cover
NO
become open when the cassette
tape is inserted?
YES
Does the start sensor pin (2) of
NO
IC7701 go to "L" level when the
cassette tape is inserted?
YES
Does pin (5) of IC7702 (BA6209)
NO
go to "H" level (about 1.8V) when
the cassette tape is inserted?
YES
Does pin (2) of IC7702 go to
NO
about11V when the cassette
tape is inserted?
YES
Is the correct voltage at the
NO
loading motor terminal when the
cassette tape is inserted?
YES
Check and replace the loading
motor.
A cassette tape is taken in, but ejected at once.
Does start sensor pulse at pin (2)
NO
of IC7701 change from "L" to "H"
level when the cassette tape is
loaded?
YES
Does end sensor pulse at pin (3)
of IC7701 change from "L" to "H" NO
level when the cassette tape is
loaded?
YES
Do the cam switches A and B
NO
operate normally when the
cassette tape is loaded?
YES
Replace IC7701
FLOW CHART NO.1-3
Fix or replace the cassette
housing.
Check the start sensor cover.
Check the start sensor and the
way up to pin (2) of IC7701.
Check pin (12) of IC7701 and all
the way up to pin (5) of IC7702.
Check IC7702 and AT12V line.
Check between IC7702 and the
loading motor.
Check the start sensor and all
the way up to IC7701.
Check the end sensor and all the
way up to IC7701.
Check cam switches and all the
way up to IC7701.
LOADING MOTOR AND EJECT TROUBLESHOOTING
A cassette tape fails to eject.
Does the capstan motor start
NO
when the EJECT button is
pressed?
YES
Does the take-up reel disk turn
NO
when the capstan motor is
running?
YES
Is reel pulse at pin (80) of
NO
IC7701 when the take-up reel
disk is turning?
YES
Is "H" level (about 1.8V) at pin
NO
(6) of IC7702 when reel pulse is
inputted?
YES
NO
Is about 11V at pin (10) of IC7702?
YES
NO
Is the correct voltage at the
loading motor terminal?
YES
NO
Does the loading motor run?
YES
Replace the cassette cam, gear,
etc.
FLOW CHART NO.1-4
See FLOW CHART NO.1-6.
Check the reel disk and reel
drive unit.
Check the take up reel sensor
and all the way to IC7701.
Check between pin (6) of IC7702
and all the way up to pin (11) of
IC7701.
Check IC7702 and "L" level of
pin (5) of it.
Check between IC7702 and all
the way up to the loading motor.
Replace the loading motor.