DOWNLOAD Sony KV-AR25M81A Service Manual ↓ Size: 5.04 MB | Pages: 89 in PDF or view online for FREE

– 9 –

• After removing the anode, short circuit the anode of the picture tube and the anode cap to the metal chassis, CRT

shield or carbon paint on the CRT.

• REMOVING PROCEDURES

1 Turn up one side of the rubber cap in the direction

a.

2 Using a thumb pull up the rubber cap firmly in the direc-

b.

3 When one side of the rubber cap is separated from the

c.

• HOW TO HANDLE AN ANODE-CAP

1 Do not damage the surface of anode-caps with

2 Do not press the rubber too hard so as not to

3 Do not turn the foot of rubber over too hard.

a

a

b

b

c

anode button

– 10 –

• The following adjustments should be made when a complete

realignment is required or a new picture tube is installed.

• These adjustments should be performed with rated power

supply voltage unless otherwise noted.

Controls and switches should be set as follows unless otherwise noted:

PICTURE control ...........................................................  normal

BRIGHTNESS control ...................................................  normal

Perform the adjustments in the following order :

1. Beam Landing

2. Convergence

3. Focus

4. White Balance

Note :  Test Equipment Required.

1. Pattern Generator

2. Degausser

3. Oscilloscope

normal

Preparation :
• In order to reduce the influence of geomagnetism on the set's

picture tube, face it east or west.

• Switch on the set's power and degauss with the degausser.

1. Input a white signal with the pattern generator.

Contrast
Brightness

2. Position neck assy as shown in Fig2-2.
3. Set the pattern generator raster signal to a green raster.
4. Move the deflection yoke to the rear and adjust with the

purity control so that the green is at the center and the blue
and the red take up equally sized areas on each side.
(See Figures 2-1 through 2-4.)

5. Move the deflection yoke forward and adjust so that the

entire screen is green. (See Figure 2-2.)

6. Switch the raster signal to blue, then to red and verify the

condition.

7. When the position of the deflection yoke has been decided,

fasten the deflection yoke with the screws and DY spacers.

8. If the beam does not land correctly in all the corners, use a

magnet to adjust it.

(See Figure 2-5.)

}

Neck assy

G2

G1

G3

Align the edge of
the neck assy with
the edge of the G2 grid.

a

b

b

c

c

d

d

a

Purity control
corrects this area.

Disk magnets or rotatable
disk magnets correct these
areas (a-d).

Deflection yoke positioning
corrects these areas.

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

Red

Blue

Green

Purity control

– 11 –

Preparation :
• Before starting this adjustment, adjust the focus, horizontal size

and vertical size.

• Receive dot/hatch signal.
• Pic mode: Personal (Pic 90%, Brightness 50%, Colour 50 %,

Hue 50%, Sharpness 50%).

1. (Moving horizontally), adjust the H.STAT control so that the

red, green and blue dots are on top of each other at the center of
the screen.

2. (Moving vertically), adjust the V.STAT magnet so that the red,

green and blue dots are on top of each other at the center of the
screen.

3. If the H.STAT variable resistor cannot bring the red, green and

blue dots together at the center of the screen, adjust the
horizontal convergence with the H.STAT variable resistor and
the V.STAT magnet in the manner given below.
(In this case, the H.STAT variable resistor and the V.STAT
magnet influence each other, so be sure to perform adjustments
while tracking.)

1

V. STAT

2

H. STAT VR

3

H. STAT VR

V. STST
Magnet

RV702
H. STAT

RV701
SCREEN (G2)

C6 Board

Center dot

R

G

B

R

G

B

Purity

BMC

BMC (Hexapole)

Purity

DY pocket

V.STAT

V.STAT

R

R

G

G

B

B

a

a

b

b

b

R

R

G

G

B

B

a

b

R

R

G

G

B

B

a

a

b

b

b

– 12 –

5

Y separation axis correction magnet adjustment.

1. Receive the cross-hatch signal and adjust [PICTURE] to [MIN]

and [BRIGHTNESS] to [STANDARD]  .

2. Adjust the Y separation axis correction magnet on the neck

assembly so that the horizontal lines at the top and bottom of
the screen are straight.

Note
1. The Red and Blue magnets should be equally far from the

horizontal center line.

2. Do not separate the Red and Blue magnets too far.

(Less than   8 mm)

Preparation:
• Before starting this adjustment, adjust the horizontal static

convergence and the vertical static convergence

4

BMC (Hexapole) Magnet.
If the red, green and blue dots are not balanced or aligned, then
use the BMC magnet to adjust in the manner described below.

R G

B

R

G

B

R

G B

R

B

R

G

G

G

B

R

B

Neck assy

Neck assy

Blue

Red

Blue

Red

VM1 board

VM1 board

R B

R B

TLH

TLV

YCH

XCV

B

R

R

B