Read Sharp VC-M303 (serv.man9) Service Manual online
39
CASSETTE
P803
TEST
P804
S809
MENU
S806
CH(+)
S811, 812
EJECT
S813
3.8V
SW 1/SW 2 INPUT VOLTAGE(V)
3.1V
2.5V
1.9V
1.2V
0.6V
POWER
S885
STOP
S884
PLAY
S883
PAUSE/STILL
S882
REC
S807
SET
S810
CH(-)
FLOW CHART NO.6 TIMER TROUBLESHOOTING (2)
Does the key switch make good
contact, when the cassette tape is
inserted?
Check switch contact.
Is there a short in the scan outs or
key inputs?
Check all the terminals of IC801
and switches for poor soldering.
Are pulses received at pins(26) thru
(29) of IC801 when the keys are
activated?
Check lines of key in and scan out.
Check IC801, IC701 and FIP data,
FIP clock, FIP CS and key data.
YES
YES
NO
NO
NO
YES
Key-in input is not received
<For jog shuttle mode
.>
Does the key switch make good
contact, when the cassette tape is
inserted?
Check switch contact.
Is there the function control voltage
inputted at the pins(87) and (88) of
IC701, when the keys are activated?
Replace IC701.
Check peripheral circuit of pins(87)
and (88) of IC701, and the function
keys.
YES
NO
NO
YES
Key-in input is not received
<Except for jog shuttle mode
.>
FLOW CHART NO.7 INFRARED R/C TROUBLESHOOTING
No operation is possible from the infrared remote control.
Dose the infrared remote control
function?
Replace infrared remote control as
required.
Is the supply voltage of 5V fed to
C813 of (+) side?
Check AT 5V and GND lines.
Is "L" pulse sent out from pin(1) of
the receiver when the infrared remote
control is activated?
Replace receiver.
Check between at pin(1) of receiver
and all the way up thru to pin(5) of
IC701.
Replace IC701.
YES
NO
YES
NO
NO
NO
YES
Is the cassette housing distorted?
Fix or replace the cassette housing.
NO
YES
YES
YES
YES
NO
YES
NO
NO
YES
NO
YES
FLOW CHART NO.8 CASSETTE CONTROL TROUBLESHOOTING(1)
A cassette tape is not take in.
NO
NO
Check start sensor cover.
Check line between start sensor and
pin(79) of IC701
Check line between pin(93) of IC701
and pin(11) of IC702.
Is the supply voltage of 12V fed to
pin(13) of IC702?
Check M 12V lines.
Check IC702.
Check line between IC702 and
loading motor.
Replace loading motor.
Is the specified voltage applied at the
loading motor terminal when the
cassette tape is inserted?
Does pin(12) of IC702 change to
about 10V when the cassette tape in
inserted?
Does pin(11) of IC702 go to a "H"
level when the cassette tape is
inserted?
Does pin(79) of IC701 change from
"H" to "L" level when the cassette
tape is inserted?
Does the start sensor cover go to
open when the cassette tape is
inserted?
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