JVC RM-C1305-1H Service Manual page 18

4.6 ADJUSTMENT PROCEDURE
4.6.1 B1 POWER SUPPLY
Measuring
Item
instrument
Signal
B1 POWER
SUPPLY generator
check
DC voltmeter
4.6.2 FOCUS ADJUSTMENT
Measuring
Item
instrument
FOCUS Signal
adjustment
generator
4.6.3 IF CIRCUIT ADJUSTMENTS
Measuring
Item
instrument
IF VCO
Remote
adjustment
control unit
VCO (CW)
TOO HIGH
ABOVE REFERENCE
BELOW REFERENCE
TOO LOW
DISPLAY : EXIT
DELAY POINT
Remote
(AGC control unit
TAKE-OVER)
adjustment
Adjustment item
2. DELAY POINT
(AGC TAKE-OVER)
1-18 (No. 52176)
Test point Adjustment part
B1 (pin 1)
GND (pin 5)
[CN00S
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
[1. IF]
2. DELAY POINT
Initial setting value
NTSC 3.58 OTHERS
VHF UHF VHF UHF
28 24 28 28
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 DC135V ± 2V.
Description
Notes:
•
Set PICTURE MODE (VSM) to "BRIGHT".
•
The final adjustment of CONVERGENCE must be done
after the FOCUS adjustment. (CONVERGENCE is changed
by FOCUS adjustment.)
When makes difference by FOCUS adjustment, should be
reconfirming PURITY adjustment.
(1) Receive a cross-hatch signal.
(2) While looking at the screen centre, adjust the FOCUS VR
so that the vertical and horizontal lines will be clear and in
fine detail.
(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) Select 1. IF from the SERVICE MENU.
(2) Select 1. VCO.
(3) Receive a broadcast signal.
(4) Check the characters colour of the BELOW 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 noise
and any decrease below it produces 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.