Sharp VC-90ET

TIMER (2) TROUBLESHOOTING
Key-in input is not received.
Check the switch contact.
FLOW CHART NO. 3
Is the key switch in good contact ?
Check !€5001, display tube and
switches for poor soldering.
1s there no rare short with the
segment or key input ?
VES
Are pulses received at pins @)~ @)
orD~@, 6) ~ © of 1c5001
when the key is activated ?
YES —
Check 1C5001 , 1C801 and signal
line of serial data, serial clock and
ready (L).
Check C5001.
INFRARED R/C TROUBLESHOOTING FLOWECHART NO.
No operation is possible from the
infrared remote control.
Does the infrared remote control NO
Replace the infrared remote
function i
control as required.
|
i
YES
Is AT 5V applied at pin @ ofthe | NO
remote control receiver ?
YES
Is “LL” pulse given out of pin @
of the receiver when the infrared
remote control is activated ?
YES
Check the AT5V and GND lines.
NO Check pin ® of 1C5001. If the pin
is okay, replace the receiver.
Is fluorescent lighting enough NO
away from the VCR set ?
YES
Is there no rare short with the key | NO
input or segment output of
1C5001 ?
Reposition the set not to be
exposed to strong light.
; Check all the terminals.
YES
Check 1C5001, IC801 and signal line
of serial data, serial clock and
ready (lL).
CASSETTE CONTROL TROUBLESHOOTING
Acassette tape is not taken in.
FLOW CHART NO.5
NO
Is the cassette housing in shape ? Check the cassette housing.
YES
Are the cam switch and cassette NO Reposition the cam switch
slider properly positioned ? :
YES
Check the cassette switch and all
the way up to pin @of !C801.
Does pin © of !C801 change from
0.8V or 1.5V to OV level w
tO | en the
cassette tape is inserted ?
YES
Does pin © of 1C803 go to "H” |NO
level when the cassette tape is
inserted ?
Check IC801 and all the way up to
pin © of [€803.
YES
Does pin @ of 1C803 go to.” H”
level when the cassette tape is Check 1C803.
inserted ?
YES
Is the correct voltage at the NO
loading motor terminal when the
cassette tape is inserted ?
YES
Replace the loading motor.
Acassette tape is taken in, but ejected at once.
Does start sensor pulse at pin G9
of IC801 change from “H” to “L
" level when the cassette tape is
loaded ?
Check between IC803 and the
loading motor.
Check the start sensor and all the
way up to !C801.
Check the cassette switch and all
the way up to {C801.
Does cassette switch pulse at pin
© of IC801 change from 0.8V or
1.5V to OV to 2.5V level when
the cassette tape is loaded ?
Replace IC801.
1306-94