Sharp vc-ga56z Service Manual page 38

FLOW CHART NO.6
Key-in input is not received.
Does the key switch make good
NO
contact, when the cassette tape is
inserted?
YES
Is there the function control voltage
inputted at the pins(87) and (88)
of IC701?
YES
Check or place the peripheral circuit
of IC701.
FLOW CHART NO.7
No operation is possible from the infrared remote control.
Operation is possible from the VCR,
but no operation is possible from the
infrared remote control.
Is the supply voltage of 5V feed to NO
pin(3) of remote control receiver?
YES
Is "L" pulse sent out pin(1) of
NO
receiver when the infrared remote
control is activated?
YES
Is there "L" pulse inputted at
NO
pin(5) of IC701?
YES
Replace IC701.
Check switch contact.
Check AT 5V lines.
Replace the remote control receiver
or replace the remote control
transmitter if necessary.
Check line between remote
control receiver and pin(5) of
IC701.
FLOW CHART NO.8
A cassette tape is not taken in.
NO
Does start sensor shutter open
when the cassette tape is inserted?
YES
NO
Does pin(79) of IC701 change from
"H" to "L" level when the cassette
tape is inserted?
YES
Does pin(11) of IC706 go to "H"
NO
(about 4.7V) level when the cassette
tape is inserted?
YES
Does pin(13) of IC706 change to
NO
about 10V when the cassette tape is
inserted?
YES
Is the specified voltage (about 10V)
NO
applied at the loading motor terminal
when the cassette tape is inserted?
YES
Replace loading motor.
FLOW CHART NO.9
A cassette tape is taken in, but ejected at once.
Does the start sensor pulse at
NO
pin(79) of IC701 change from "L" to
"H" level when the cassette tape is
loaded?
YES
NO
Does the end sensor pulse at pin(85)
of IC701 change from "L" to "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 shutter.
Check line start sensor and all the
way up thru to pin(79) of IC701.
Check line pin(9) of IC701 and all
the way up thru to pin(11) of IC706.
Check IC706.
Check between IC706 and loading
motor.
Check start sensor and all the way
up thru to IC701.
Check end sensor and all the way
up thru to IC701.
Check cam switch and all the way
up thru to IC701.