JVC LT-26WX84 Service Manual page 53

Mesuring
Item
instrument
WHITE Remote control
BALANCE unit
(HIGHLIGHT)
Signal generator
4.7.3 MTS CIRCUIT
Measuring
Item
instrument
MTS INPUT MPX Signal
LEVEL generator
Remote
control unit
MTS TV audio
SEPARATION multiplex
signal
generator
Oscilloscope
Remote
control unit
L-Channel
signal waveform
1 cycle
Test point Adjustment part
[1. PICTURE/SOUND]
S13: RDRV (R DRIVE)
S15: GDRV (G DRIVE)
S17: BDRV (B DRIVE)
S19: CUTR (R CUTOFF)
S21: CUTG (G CUTOFF)
Test point Adjustment part
[1.PICTURE/SOUND]
A18: IN LEVEL
L OUT [1.PICTURE/SOUND]
R OUT A19: LOW SEP
A20: HI SEP
R-Channel
crosstalk portion
Minimum
Description
(1) Input NTSC 75% all-white signal.
(2) Set "VIDEO STATUS" to STANDARD.
(3) Set "ASPECT" to FULL.
(4) Select "COLOR TEMPERATURE" to "LOW".
(5) Select "1.PICTURE/SOUND" from the SERVICE
MODE.
(6) Fix one of < S13 > (R DRIVE), < S15 > (G DRIVE),
or < S17 > (B DRIVE). Lower the two that are not
fixed so that the all-white screen is equally white
throughout.
Set one or more of < S13 >, < S15 >, and < S17 >
to "255".
(7) Check that white balance is properly tracked from
lowlight to highlight.
(8) Press the [MUTING] key to memoirze the set value.
(9) Input 1125i 75% all-white signal.
(10) Repeat steps (5) to (8) above.
(11) Input 525i all-white signal.
(12) Repeat steps (5) to (8) above.
Description
(1) Input the color bar signal (400Hz).
(2) Select 1.PICTURE/SOUND from the SERVICE
MODE.
(3) Verify that the < A18 > (IN LEVEL) 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
MONITOR OUT, and display one cycle portion of the
300Hz signal.
(3) Change the connection of the oscilloscope to R OUT
pin of the MONITOR OUT, and enlarge the voltage
axis.
(4) Select 1.PICTURE/SOUND from the SERVICE
MODE.
(5) Set the initial setting value of the < A19 > (LOW
SEP).
(6) Adjust the < A19 > so that the stroke element of the
300Hz signal will become minimum.
(7) Change the signal to 3kHz, and similarly adjust the
< A20 > (HI SEP).
(8) Press the [MUTING] key to memorize the set value.
(No.YA089)1-53