ADJUSTMENTS
PROCEDURES
4.
High
Voltage
Adjustment
4-1
DEF
SUB
and
DEF/HV
High
Voltage
Adjustments
(1)
Connect
a
high
voltage
probe
under
the
CRT's
anode
cap
User
High
Voltage
probe
\whose
maximum
voltage
is
rated
more
than
1.5kV
and
has
internal
an
impedance
Greater
than
1000MQ.
(2)
Input
all
black
video
signal.
(3)
Set
the
VR
of
the
FBT
(DEF/HV
PWB
T5001)
to
the
MIN
position.
(4)
Adjust
VR9003
(DEF
SUB
PWB)
so
that
the
high
voltage
equals
29±0.3Vdc.
(5)
Remove
the
high
voltage
probe
and
seal
VR9003
\with
silicone
and
a
cap
to
comply
with
DHHS
require
ments.
4-2
DEF
SUB
and
DEF/HV
High
Voltage
Protector
Adjustment
(1)
Input
NTSC
all
black
video
signal
and
turn
FBT
Screen
VR
fully
counterclockwise.
(2)
Connect
the
voltmeter
first
to
TP2001-TP
GND
and
then
TP2002-TP
GND
and
adjust
VR2001
so
that
TP2001-TP
GND
=
TP2002-TP
GND,
approximately
8.8Vdc.
(3)
Remove
the
voltmeter
from
the
circuit
and
seal
VR2001
with
silicone
and
a
cap
to
comply
with
DHHS
requirements.
5.
Video
Chroma
Circuit
Adjustment
5-1
PAL
Comb
Filter
Adjustment
(1)
Input
the
PAL
color
bar
signal.
(2)
Set
the
Video
Select
SW
to
"PAL".
(3)
Connect
the
oscilloscope
to
TP7003
on
the
Video
PWB.
(4)
Adjust
VR7101
and
T7101
and
set
the
chroma
signal
component
to
the
MIN
position.
Note:
VR7101.
T7101,
and
TP7003
on
the
Video
PWB
(PWC-3838A).
5-2
Sub-Bright
and
Sub-Contrast
Adjustments
(1)
Input
the
NTSC
16
gradation
gray
scale
pattern
which
must
have
0%
all-black
and
100%
all-white
shades.
(2)
Set
the
Video
Select
SW
to
the
"NTSC”
position.
(3)
Connect
the
oscilloscope
to
TP7001
(Green
signal)
and
TP
GND.
(4)
Adjust
VR7202
(SUB-BRIGHT)
and
VR7201
(SUB-CONT)
until
the
waveform
appears
as
shown
below.
White
•
>1^
1
©White
and
black
level
portion
(contrast)
0.8
Vp-p±0.05
Vp-p
(Adjust
with
VR7201)
1
1
1
I
1
l
I
1
1
l
Black
1
•
®
1
About
3V
(D
Blanking
(sync)
portion
0.05
Vp-p+0
Vp-p,
-0.05
Vp-p
(Adjust
with
VR7202)
Note:
Simplify
adjustment
by
keeping
sync
por
tion
to
a
minimum.
OV
Note:
TP7001,
VR7201,
VR7202,
and
TP
GND
are
on
the
Video
PWB.
Also
correct
wave
forms
are
easier
to
read
and
adjust
when
the
scope's
probe
is
grounded
at
TP
GND
(Video
PWB).
17
Summary of Contents for PG-2740
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