JVC AV-21L41/BK Service Manual page 16

ADJUSTMENTS
B1 POWER SUPPLY
Measuring
Item
instrument
Check of Signal
B1 Power generator
Supply
DC Volt-
meter
FOCUS ADJUSTMENT
Measuring
Item
instrument
Adjustment Signal
of FOCUS generator
IF CIRCUIT ADJUSTMENT
Measuring
Item
instrument
Adjustment Signal
of VCO(CW) generator
Remote
control unit
VCO (CW) ***.** MHz
TOO HIGH
ABOVE REFERENCE
JUST REFERENCE
BELOW REFERENCE
TOO LOW
AFT ADJUST
VCO ADJUST
FINE
Do not adjust
ADJUSTMENT AT THIS POINT IS USELESS
Test point Adjustment part
TP-91 (B1)
TP-E (# # # # )
Test point Adjustment part
FOCUS VR
[In HVT]
Test point Adjustment part
1. VCO
YELLOW
***(**) ***(**)
***(**) ***(**)
***(**) ***(**) ***(**) ***(**)
DISP : EXIT
TOO HIGH
ABOVE REFERENCE
JUST REFERENCE
BELOW REFERENCE
TOO LOW
ADJUSTMENT POINT
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 DC114.5 ± 1.5V.
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.
● Please use signal generator which is correct proof about the
sending frequency.
1. Input the PAL full colour bar (210.25MHz) signal.
2. Select 1.IF from the SERVICE MENU.
3. Press 1 key and select 1.VCO.
4. Select VCO ADJUST with MENU ▲ / ▼ key.
5. 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.
6. Select AFT ADJUST with MENU ▲ / ▼ key.
7. Press MENU -/+ key until the characters JUST REFERENCE
changes blue to yellow.
8. Press the DISPLAY key three times to return to normal screen.
No. 51859
Description
Description
Description
AV-21L41
19