JVC AV-20N3/D CRT Television User Manual


 
No. 52025
A
V-20N3
A
V-20NMG3
A
V-20NMG3B
20
ADJUSTMENTS
B1 POWER SUPPLY
Item
Measuring
instrument
Test point Adjustment part Description
Check of
B1 Power
Supply
Signal
generator
DC Volt-
meter
TP-91 (B1)
TP-E (#
##
#)
1. Input a whole black signal.
2. Connect a DC voltmeter to TP-91(B1) and TP-E (#).
3. Make sure that the voltage is DC116.5±2.0V.
FOCUS ADJUSTMENT
Item
Measuring
instrument
Test point Adjustment part Description
Ad justment
of FOCUS
Signal
generator
FOCUS VR
[In HVT]
1. Input a cross-hatch signal.
2. While watching the screen, adjust the FOCUS VR to make the
vertical and horizontal lines as fine and sharp as possible.
3. Make sure that when the screen is darkened, the lines remain in
good focus.
IF CIRCUIT ADJUSTMENT
Item
Measuring
instrument
Test point Adjustment part Description
Please use signal generator which is correct proof about the
sending frequency.
Ad justment
of VCO
(
CW
)
Signal
generator
Remote
control unit
1. VCO
1. Input the PAL full colour bar (210.25MHz) signal.
2. Enter the SERVICE MENU.
3. Select 1.IF from the SERVICE MENU.
4. Press 1 key and select 1.VCO.
5. Select VCO ADJUST with MENU / key.
6. Press MENU -/+ key until the colour of the characters TOO
HIGH changes blue to yellow. Then gradually press the MENU
-/+ key until the TOO LOW changes yellow. At this time, confirm
that the value of VCO ADJUST is near +00.
7. Select AFT ADJUST with MENU / key.
8. Press MENU -/+ key until the characters JUST REFERENCE
changes blue to yellow.
9. Press the DISPLAY key three times to return to normal screen.
VCO (C W)
***.**
MHz
TOO HIGH
ABOVE REFERENCE
JUST REFERENCE
BELOW R EFEREN CE
TOO LOW
AFT ADJUST
***(**)
***(**)***(**)
***(**)
VCO ADJUST
***(**)
***(**)***(**)
***(**)
FINE
DISP : EXIT
YELLOW
D
o
n
ot
adjust
ADJUSTMENT AT THIS POINT IS USELESS
ABOVE REFERENCE
TOO HIGH
B ELO W RE F E RE NC E
JUS
T REFERE N
C
E
TOO LOW
ADJUSTMENT POINT