Sharp VC-MH80 Service Manual page 51

FLOW CHART NO.8 CASSETTE CONTROL TROUBLESHOOTING (1)
A cassette tape is not taken in.
I
,
NO
Are the start sensor cover go to
NO
open when the cassette tape is
YE5
NO
Does pin (87) of It701 change
from "H" to "L' level when the
cassette tape is inserted?
NO
Does pin (5) of IC704 go to a "H"
(about 1.7V) level when the
cassette tape is inserted?
YES
NO
Does pin (2) of lC704 change to
about 1OV when the cassette tape
is inserted?
NO
Is the specified voltage applied at
the loading motor terminal when
the cassette tape is inserted?
YES
Replace loading motor.
Fix or replace the cassette housing.
Check start sensor cover.
Check start sensor and all the way
up thru to pin (87) of IC701.
Check line between pin (96) of
pin (5) of IC704.
Check IC704.
Check between IC704 and loading
FLOW CHART NO.9 CASSETTE CONTROL TROUBLESHOOTlNG (2)
A cassette tape is taken in, but ejected at once.
Does the start sensor pulse at pin
(87) of IC701 change from a "L' to
"H" level when the cassette tape is
loaded?
YES
Does the end sensor pulse at pin NO
(88) of IC701 change from a "L" to
a "H" level when the cassette tape
is loaded?
YES
Does the master cam mode shifter NO
operate normally when the
cassette tape is loaded?
YES
Replace IC701.
Check start sensor and all the way
up thru to IC701.
Check end sensor and all the way
Check cam switch and all the way
up thru to 1~701.