GDM-20SE2T5 (serv.man2) - Sony Monitor Service Manual (repair manual). Page 2

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1.

Enter the full white signal. (or the full black dots signal).

2.

Adjust the contrast to the maximum.

3.

Make the screen monogreen.

4.

Adjust the brightness is easy to see with the G2 resistor.

5.

Reverse the DY, and adjust coarsely the purity magnet so
that a green raster positions in the center of screen.

6.

Moving the DY forward, adjust so that an entire screen be-
comes monogreen.

7.

Adjust the tilt of DY, and fix lightly with a clamp.

•

1.

Put the set inside the Helmholtz coil.

2.

Input the single green signal and set the CONT control to
MAX.

Note: After the W/B adjustment with 9300K, measure an aver-

age of 

Σ

Ik when a full white signal is entered in the CONT

MAX/BRT CENT status. Then make adjustment so that
the specified screen can be attained after aging for 2 hours
with Ik equivalent to 30% of the average value.

3.

Demagnetize the metal part of the chassis with the hand de-
gausser and coil degausser, and the CRT surface with the
hand degausser.
Input AC 230V to AC IN, turn on and off the power to per-
form auto degaussing. (Perform auto degaussing by setting
“MONCONREG2”=152. Return to the original value after
use.)
Demagnetize the CRT surface with the hand degausser
again.

Note:
(1) The power must be turned off during chassis degaussing.
(2) Adjust in a non-magnetic field. BV=45uT.
(3) If adjusting in a magnetic fields, add the shift from the non-

magnetic field in your estimation.

4.

Attach the wobbling coil to the designated part of the CRT
neck.

5.

Attach the sensor of the landing adjustment unit on the CRT
surface.

6.

Adjust the DY position and purity, and the DY tilt, and land-
ing of the center and 4 corners with the landing checker.

Note: Using RV701, 702, 703 and 704 on the L board, adjust the

landing of four corners.

7.

For the up/down and left/right swing, swing the DY and in-
sert a wedge so that the up and down pins are equal at the top
and bottom and the horizontal trapezoid is equal at the left
and right. Insert the wedge firmly so that the DY does not
shake.

8.

Check the landing of each corner, and if it does not satisfy
the specification, adjust the landing of four corners using
RV701, 702, 703 and 704 on the L board. If this adjustment
failed, attach the Disk-Mg onto the funnel section and add
correction value.

Note:
(1) Do not paste more than 2 magnets to one corner.
(2) Paste within 80 to 100 mm from the DY on the diagonal line

of the magnet.

(3) If using the magnet, be sure to demagnetize with the hand

degausser and check. (The power must be turned off during
chassis degaussing.)

9.

Remove the sensor and wobbling coil.

10. Switch the signal to R.G.B., and check that each color is

pure.

11. Check that the DY is not tilting, and fix the purity Mg with a

white pen.

A difference between red and blue
must be within the specification
given right.

* Adjustment and measurement should be made at the points one

inch inside the fluorescent screen.

 

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6

 

±

 

6

 

±

 6

 

±

 

6

 

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4

 

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 6

 

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6

 

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6

 

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 6

<Specifications>
Adjust so that the green is within
the specification given right.
Adjust RV within 

±

1.

The red and blue must be within
the specification given right with
respect to the green.

0 

±

 

3

0 

±

 7.5 0 

±

 3

0 

±

 

5

0 

±

 

5

0 

±

 5

0 

±

 

3

0 

±

 7.5 0 

±

 3

(

µ

m)

(

µ

m)

10

10

10

10

7

10

10

10

10

(

µ

m)