Toshiba 40WH08B, Service Manual

Page: 7 / 98

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GENERAL ADJUSTMENTS
In case of warming up of more than 2 hours under a condition
that the large anode current is running through the projection
tube so that for example the all-white pattern appears, adjust
to obtain the sharpest focus while observing the whole screen
like in the RED case.
11. Use the focus VR of “G” of the focus pack in order to ad-
just the electric focus in the middle section of the screen
to its sharpest level.
Note: Normally the most clearly visible point of the scanning
line is the sharpest point of the Green focus, however as
the characteristics vary depending on the projection tube,
the sharpest focus points of the vertical and horizontal
lines may not match each other, thus when you turn the
focus VR, if the picture tends to be tremendously unstable
(rolls horizontally or vertically), adjust the balance of the
vertical and horizontal lines to its best position.
12. Check the GREEN focus of the whole screen and if
necessary repeat steps 10 and 11.
13. Fix the GREEN lens by tightening up its fixing screws.
14. Expose only BLUE by covering the RED and GREEN
lenses with caps.
15. Display the internally-generated black cross-hatch.
16. Loosen the BLUE lens fixing screws (refer to Fig. a), and
adjust the BLUE lens focus while observing the middle
and peripheral screen sections.
17. Use the focus VR of “B” of the focus pack in order to adjust
the focus in the middle section of the screen to its sharpest
level.
(The point of the Blue focus becomes sharpest when the
brightness level of BLUE is lowest, the cross-hatch is
clearly visible.)
TILT ADJUSTMENT
Rotate R, G, B deflection yoke so that picture becomes hori-
zon, then fasten screw.
CENTERING ADJUSTMENT
1.
Stretch a thread between two center of screen edge
(top and bottom, left and right).
2. Select the adjustment mode. (See page 10.)
3. Press TV/VIDEO button on the Remote Control to display
the black cross-hatch.
4. Adjust G centering magnet so that the cross-hatch pat-
tern center comes to screen center.
5. Perform HEIGHT adjustment . (See page 14.)
6. Perform WIDTH adjustment. (See page 14.)
7. Check whole quality of green line.
8. Adjust R, B centering magnet so that the cross-hatch pat-
tern center comes to screen center.
Note: Keep in mind that only the BLUE electric focus is ad-
justed with the black cross-hatch.
18. Check the BLUE focus of the whole screen and if neces-
sary repeat steps 17 and 19.
19. Fix the BLUE lens by tightening its fixing screws.
Note: The aim of the above-described adjustment procedure
for the Green lens focus is to obtain the best lens focus
after 2 - 3 hours of warming up taking into account the
focus drift; it applies if the warming up time before the
adjustment is less than 30 minutes. (The horizontal line
in the screen middle section tends to be slightly red-
flared.)