JVC HD-56FH97 Service Manual page 31

4.7.3 VIDEO CIRCUIT
Measuring
Item
instrument
WHITE Remote
BALANCE control unit
(HIGHLIGHT)
Signal
generator
4.7.4 MTS CIRCUIT
Measuring
Item
instrument
MTS INPUT Remote
LEVEL control unit
MTS TV audio
SEPARATION multiplex
signal
generator
Oscilloscope
Remote
control unit
L-Channel
signal waveform
1 cycle
Test point Adjustment part
[1.ADJUST]
S001: R DRIVE (Red drive)
S002: G DRIVE (Green drive)
S003: B DRIVE (Blue drive)
Test point Adjustment part
[1.ADJUST]
T001: INPLEVEL
L OUT [1.ADJUST]
R OUT T002: LOWSEPA
T003: HIGHSEPA
R-Channel
crosstalk portion
Minimum
Input the stereo R signal
(3kHz) and change
Description
(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.
Description
(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.
(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.
(No.YA409)1-31