2-Pole Magnet Adjustment; Defocus Adjustment - Sony KP-43T90 Service Manual

2-6. 2-POLE MAGNET ADJUSTMENT

(GREEN, RED)
1. Display a dot pattern (see the details of using the internal test
patterns at the end of the previous section).
2. Enter the service mode.
3. Cover the red and blue CRT lenses with lens caps to allow only green
to show (or use the method shown in the note below for turning off the
CRTs individually without using lens caps).
4. Turn the green focus control on the focus block to the right and set it
to overfocus to enlarge the spot (the dot). See fi gure at the end of
Section 2-3 for the location of the 2-pole magnet adjusting tabs.
5. Adjust the green CRT's 2-pole magnet so that the small bright spot is
in the center of the large defocused spot.
6. Adjust the green focus control on the focus block and set it for the
best focus.
7. Repeat steps 1 through 6 for the red CRT, except now you will
cover the green and blue CRT lenses with lens caps to allow
only red to show (or use the method shown in the note below
for turning off the CRTs individually without using lens caps) and you
will adjust the red focus control on the focus block.
Note: If lens caps are unavailable, you can cut off the unnecessary color
beams in the service mode by individually changing the data from "1"
to "0" in category VPNT, item 28 RON (red), item 29 GON (green), or
item 30 BON (blue).
Use the center dot
2-7. 4-POLE MAGNET ADJUSTMENT
(GREEN, RED, BLUE)
1. Display a dot pattern (see the details of using the internal test
patterns at the end of section 2-5, item 4).
2. Enter the service mode.
3. Cover the red and blue CRT lenses with lens caps to allow only green
to show (or use the method shown in the note below for turning off the
CRTs individually without using lens caps).
4. Turn the green focus control on the focus block to the left and set it to
under-focus to enlarge the spot.
5. Adjust the 4-pole magnet so that the enlarged spot in the center of the
screen becomes a perfect circle.
6. Adjust the green focus control on the focus block and set it for the best
focus.
7. Repeat steps 1 through 6 for the red CRT, except now you will
cover the green and blue CRT lenses with lens caps to allow
only red to show (or use the method shown in the note below
for turning off the CRTs individually without using lens caps) and you
will adjust the red focus control on the focus block.
Large de-focused spot
Small focused spot
8. Repeat steps 1 through 6 for the blue CRT, except now cover the
green and red CRT lenses with lens caps to allow only blue to show.
Adjust the blue focus control on the focus block (or use the method
shown in the note below for turning off the CRTs individually without
using lens caps). However, for the blue CRT do not make the
enlarged spot a perfect circle as indicated in step 5; instead, adjust
the 4-pole magnet so that the height of the enlarged blue spot in the
center of the screen is approx. 1.5 times the width of the spot.
Note: If lens caps are unavailable, you can cut off the unnecessary color
beams in the service mode by individually changing the data from "1"
to "0" in category VPNT, item 28 RON (red), item 29 GON (green), or
item 30 BON (blue).
.
Use the center dot
2-8. DEFOCUS ADJUSTMENT (BLUE)
Note: Adjust the blue dot to be slightly larger than red and green dots.
This adjustment provides a more pleasing picture to the customer.
1. Select the video menu and set the picture mode to "VIVID".
2. Enter service mode.
3. Change TV mode to the video-1 input mode.
4. Select adjustment category "PJE", and press 6 as many times as
necessary to display the dot pattern on the screen.
5. Adjust the blue focus control on the focus block to adjust the diameter
of the dots in the center of the screen as shown in the fi gure below.
FOCUS ADJUSTMENT POINT:
43"
Screen Size
6mm
Diameter
— 15 —
KP- 43T90 / 48V90 / 53V90 / 61V90
x
y
x : y = 1:1.5 (BIue)
x : y = 1:1 (Green, Red)
Dmm Max
53" 61"
8mm 9mm