42
13VT-N100
13VT-N150
13VT-CN10
TROUBLESHOOTING OF VCR SECTION
Check/replace X7701
and/or IC2001.
ELECTRICAL TROUBLESHOOTING
VCR POWER TROUBLESHOOTING
FLOW CHART NO.1-1
The VCR is dead.(No power)
Unplug the AC power cord.
Replug it a few minutes later.
Are the AT 5V and AT 12V
lines normal?
Are the AT 5V and GND
lines properly connected
with IC2001?
Is there oscillation
(16MHz) at pins (38) and
(39) of IC2001?
Are the PC 9V and PC 5V
lines normal?
Check power circuit.
Check poor soldering.
Check power circuit.
Check the sensor inputs
to IC2001 from
mechanism. (CAM
switches,start/end
sensors,and reel sensors)
KEY-IN TROUBLESHOOTING
FLOW CHART NO.1-2
Key-in input for VCR is not received.
Is the key switch in good
contact?
Is there short-circuit in the
key input?
Are signals received at
pin (8) of IC2001 when
the key is activated?
Check IC2001.
Check the switch contact.
Check IC2001 and switches
for poor soldering.
Check key lines to input
IC2001.
YES
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
Check pin (21) of IC2001 and all
the way up to pin (5) of IC7701.
NO
NO
CASSETTE CONTROL TROUBLESHOOTING FLOW CHART NO.1-3
A cassette tape is not taken in.
YES
YES
YES
YES
YES
YES
Fix or replace the cassette
housing.
Check the start sensor cover.
Check the start sensor and the
way up to pin (5) of IC2001.
NO
NO
NO
YES
YES
YES
Check IC7701 and AT12V line.
Check between IC7701 and the
loading motor.
A cassette tape is taken in, but ejected at once.
Replace IC2001
Is the cassette housing distored?
Does the start sensor cover
become open when the cassette
tape is inserted?
Does the start sensor pin (5) of
IC2001 go to "L" level when the
cassette tape is inserted?
Does pin (5) of IC7701 (BA6209)
go to "H" level (about 1.8V) when
the cassette tape is inserted?
Check and replace the loading
motor.
Is the correct voltage at the
loading motor terminal when the
cassette tape is inserted?
Does pin (2) of IC7701 go to
about11V when the cassette
tape is inserted?
Do the cam switches A and B
operate normally when the
cassette tape is loaded?
Does end sensor pulse at pin (6)
of IC2001 change from "L" to "H"
level when the cassette tape is
loaded?
Does start sensor pulse at pin (5)
of IC2001 change from "L" to "H"
level when the cassette tape is
loaded?
Check the start sensor and all
the way up to IC2001.
Check the end sensor and all the
way up to IC2001.
Check cam switches and all the
way up to IC2001.
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