JVC AV-29WX14/G Service Manual page 18

4.7 ADJUSTMENT PROCEDURE
4.7.1 B1 VOLTAGE
Measuring
Item
instrument
Signal
B1 VOLTAGE
check generator
DC voltmeter
4.7.2 FOCUS ADJUSTMENT
Measuring
Item
instrument
FOCUS Signal
adjustment
generator
4.7.3 IF CIRCUIT ADJUSTMENTS
Measuring
Item
instrument
IF VCO
Remote
check
control unit
VCO (CW)
TOO HIGH
ABOVE REFERENCE
JUST REFERENCE
BELOW REFERENCE
TOO LOW
DELAY POINT
Remote
(AGC control unit
TAKE-OVER)
adjustment
Adjustment item
2. DELAY POINT
(AGC TAKE-OVER)
1-18 (No. YA104)
Test point Adjustment part
B1 (pin 1)
GND (pin 5)
[CN00X
connector
in MAIN
PWB]
Test point Adjustment part
FOCUS VR
[In HVT]
Test point Adjustment part
[1. IF]
1. VCO (CW)
. MHz Receiving frequency
YELLOW
DISPLAY : EXIT
[1. IF]
2. DELAY POINT
Initial setting value
NTSC 3.58 OTHERS
VHF UHF VHF UHF
30 30 30 30
Description
(1) Receive a black and white signal.
(2) Connect a DC voltmeter between B1 and GND (between
pins 1 and 5 of the connector CN00S).
(3) Make sure that the voltage is DC134.5V ± 2V.
Description
Notes:
•
Set PICTURE MODE (VSM) to "BRIGHT".
[AV-29WX14/G, AV-29WX14/S, AV-29WX24/L only]
•
The final adjustment of CONVERGENCE must be done
after the FOCUS adjustment. (CONVERGENCE is affected
by the FOCUS adjustment.)
If any aeviation in CONVERGENCE is found, PURITY must
be adjusted to restore the convergence.
(1) Receive a crosshatch signal.
(2) Adjust the FOCUS VR so that the vertical and horizontal
lines will be clear and in fine detail on the screen.
(3) Make sure that the picture is in focus even when the screen
gets darkened.
Description
Note:
•
Under normal conditions, no adjustment is required.
(1) Receive a broadcast signal.
(2) Select 1. IF from the SERVICE MENU.
(3) Select 1. VCO.
(4) Check the characters colour of the JUST REFERENCE
displayed to yellow.
(5) Press the [DISPLAY] key three times to return to normal
screen.
(1) Receive a black and white broadcast signal (colour off).
(2) Select 1. IF from the SERVICE MENU.
(3) Select 2. DELAY POINT.
(4) Adjust in order to eliminate any noise or beat from the
image. Any increase above the initial value produces the
noise and any decrease below it produces the beat.
(5) Press the [DISPLAY] key three times to return to the normal
screen.
(6) Turn to other channels and make sure that there are no
irregularities.