JVC HD-56FH97 - 56" Rear Projection TV, Service Manual

Page: 31 / 35

(No.YA409)1-31
4.7.3 VIDEO CIRCUIT
4.7.4 MTS CIRCUIT
Item
Measuring
instrument
Test point Adjustment part Description
WHITE
BALANCE
(HIGHLIGHT) Remote
control unit
Signal
generator
[1.ADJUST]
S001: R DRIVE (Red drive)
S002: G DRIVE (Green drive)
S003: B DRIVE (Blue drive) (1) Receive a NTSC 75% all white pattern.
(2) Set "VIDEO STATUS" to
"STANDARD" .
(3) Set "ASPECT" to "FULL" .
(4) Select "COLOR TEMPERATURE" to "LOW" .
(5) Select "1.ADJUST" from the SERVICE
MODE.
(6) Adjust to keep one of < S001 > (Red drive),
< S002 > (Green drive) or < S003 > (Blue
drive) unchanged, then lower the other two
so that the all-white screen is equally white
throughout.
NOTE:
Set one or more of < S001 > , < S002 > , and
< S003 > to "138" .
(7) Check that white balance is properly tracked
from low light to high light. If the white balance
tracking is deviated, adjust to correct it.
(8) Press the [MUTING] key to memoirze the set
value.
Item
Measuring
instrument
Test point Adjustment part Description
MTS INPUT
LEVEL Remote
control unit [1.ADJUST]
T001: INPLEVEL (1) Receive any broadcast.
(2) Select
"1.ADJUST" from the SERVICE
MODE.
(3) Verify that the < T001 > (INPLEVEL) is set at
its initial setting value.
(4) Press the [MUTING] key to memorize the set
value.
MTS
SEPARATION TV audio
multiplex
signal
generator
Oscilloscope
Remote
control unit
L OUT
R OUT [1.ADJUST]
T002: LOWSEPA
T003: HIGHSEPA (1) Input the stereo L signal (300Hz) from the TV
audio multiplex signal generator to the antenna
terminal.
(2) Connect an oscilloscope to L OUT pin of the
AUDIO OUT , and display one cycle portion of
the 300Hz signal.
(3) Change the connection of the oscilloscope to
R OUT pin of the AUDIO OUT , and enlarge the
voltage axis.
(4) Select "1.ADJUST" from the SERVICE
MODE.
(5) Set the initial setting value of the < T002 >
(LOWSEPA).
(6) Adjust the < T002 > so that the stroke element
of the 300Hz signal will become minimum.
(7) Press the [MUTING] key to memorize the set value.
(8) Input the stereo R signal (3kHz) and change
the connection of the oscilloscope to L OUT
pin of the AUDIO OUT .
(9) Similarly adjust < T003 > (HIGHSEPA).
(10) Press the [MUTING] key to memorize the set value.
L-Channel
signal waveform R-Channel
crosstalk portion
Input the stereo R signal
(3kHz) and change
Minimum
1 cycle