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TROUBLESHOOTING
[
ELECTRICAL
VCR POWER TROUBLESHOOTING
The VCR is dead. (No power)
Unplug the AC power cord. Replug
it a few minutes later.
I
I
I
Is the fuse F701 alright in the TV
power PWB 1
I
I
Are the AT 12V and ATBV lines
normal in the VCR PWB ?
Is the AT 5V linenormal 7
YES
I
Are the AT 5V and GND lines
properly connected with IC8801 7
Does pin (37) of ICBBOl change
NO
from * L w to * H " level when
AT 5V line changes OV to 5V with
the AC cord being plugged in or
ALL CLEAR button being pressed
and released ?
YES
Does pin (24) of IC8801 change
NO
from m L - to " H . level when
the power button is pressed to
turn the power on ?
N O
Is the PC 9V line normal ?
NO
Is the PC 5V line normal ?
I
I
Check wire harness to mechanism
and the sensor inputs to IC8801
OF VCR SECTION
FLOW CHART NO. l-l
I
Replace the fuse.
1
Check fuse resistor and transistor
trouble of the ower ctrcurt m the
Check poor soldering.
I
Check pin (37) of IC8801 or IC8802
Check power key input to IClOOl
and serial datasl clocks between
Check 4756 P-CON (L) Signal at
pin (26) of IClOOl and 4760 in the
TV mother PWB.
I
I
CASSETTE CONTROL TROUBLESHOOTING
cassette tape Is not taken in.
A
YES -,,
Is the cassette housing distored 1
Does the start sensor cover
NO
become open when the cassette
tape is inserted 7
I
I
Does the start sensor pin (86) of
NO
cassette tape is inserted 7
Does pinJ5) of lC8803 BA6209)
o to "H level (about .8V when __I___)
e cassette tape is inserte II
1
Does
in (2) of lC8803 go to
NO
is inserted 1
YES
Is the correct volta e at the
NO
C h e c k b e t w e e n lC8803 a n d t h e
loading terminal w en the cassette
tape is mserted 1
$-YES
Check and replace the loading
motor.
A cassette tape Is taken in, but ejected at once.
Does start sensor pulse at pin (86) of
level when t 9, e cassette tape is loaded 7 -
Does end sensor pulse at pin (85) of
NO
to " H "level
l
when the cassette tape is loaded 7
J-YES
Do the cam switches A and 8 operate
NO
when the cassette tape is
loaded !
(at pins (83) and (84))
(refer to MECHANISM flow chart)
I
I
Replace lC8801.
FLOW CHART NO. 11
Fix or replace the cassette
housing.
1
Check the start sensor cover.
1
Check the start sensor and the way
up to pin (86) of IC8801.
I
Check pin (8) of IC8801 and all the
way up to pin (5) of lC8803.
I
Check I(38803 and AT12V line.
loading motor.
FLOW CHART NO. l-3
r
1
Check the start sensor and all the
way up to IC8801.
Check the end sensor and all the way
up to IC8801.
Check cam switches and all the way up
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