JVC AV-20N3/D, AV-20NMG3/-A Adjustments, B1 Power Supply, Focus Adjustment, If Circuit Adjustment

AV-20N3

AV-20NMG3

AV-20NMG3B

ADJUSTMENTS

B1 POWER SUPPLY

Item	Measuring	Test point	Ad justment part		Description
	instrument
Check of	Signal	TP-91 ( B1)		1.	Input a whole black signal.
B1 Power	generator	TP-E (#)		2.	Connect a DC voltmeter to TP-91(B1) and TP-E (#).
Supply
				3.	Make sure that the voltage is DC116.5±2.0V.
	DC Volt-
	meter

FOCUS ADJUSTMENT

Item	Measuring	Test point	Ad justment part		Description
	instrument
Ad justment	Signal		FOCUS VR	1.	Input a cross-hatch signal.
of FOCUS	generator		[In HVT]	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

Ad justment part

Description

Ad justment		Signal				1. VCO
of VCO(CW)		generator
		Remote
		control unit
	VCO (CW) ***.** MHz
	TOO HIGH
	ABOVE REFERENCE
	JUST REFERENCE				YELLOW
	BELOW REFERENCE
	TOO LOW
	AFT ADJUST			** *(* *)
	VCO ADJUST			** *(* *)
	FINE				Do no t adjust
			DISP : EXIT

TOO HIGH

ABOVE REFERENCE

J US T R EFE RE NC E

BELOW REFERENCE

●Please use signal generator which is correct proof about the sending frequency.

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.

TOO LOW

ADJUSTMENT AT THIS POINT IS USELESS ADJUSTMENT POINT

20 No. 52025