Toshiba CF3254J Service Data page 9

mM SCREEN-CORNER CONVERGENCE
When the misconvergence is still evident on corners
even though the above adjustment is done, use the
ferrite sheet (Part No. 23993622) to correct
misconvergence.
1.
Ferrite
Sheets
Put ferrite sheets into the space under the yoke.
Decide such position that misconvergence
becomes minimum, watching picture screen. (See
figure below.)
. Remove cover paper of ferrite sheet to stick it in the
place on the tube. Put adhesive tapes on ferrite
sheets to fix.
For correcting misconv.
on the position A
Ferrite
Sheets
CRY GRAY SCALE ADJUSTMENT
1.
z
3.
4.
Tune in an active channel.
Set the COLOR Conirol to minimum.
Turn the SCREEN Control (on T1461) fully counter-
clockwise.
Set the SERVICE Switch on the CRT DRIVE Board
to "SERV." position (see figure below). The
picture will become a single horizontal line.
(Neutral)
| NORM.
SERV.
A single
horizontal
line
. Rotate the RED, GREEN and BLUE BIAS Controls
(R956, R957, R958) fully counterclockwise and
return them by 45 degrees.
. Set the GREEN and BLUE DRIVE Controls (R952,
R953) to the mid-position.
. Gradually rotate the SCREEN Control (on T7461)
clockwise until the first horizontal line appears
slightly on the screen, and leave it.
. Adjust the remaining two BIAS Controls to obtain
the slightly lighted horizontal line in the same
levels of three (red, green, blue) colors (The line
should be white if the BIAS Controls are adjusted
properly.)
. Set the SERVICE Switch to "NORM." position.
. Set the BRIGHT and CONTRAST Controls to
maximum.
. Adjust the BLUE and GREEN DRIVE Controls to
obtain proper white-balanced picture in high light
areas.
. Adjust the BRIGHT and CONTRAST Controls to
obtain dark gray raster. Then check the white
balance in low brightness. If the white balance is
not proper, retouch the BIAS Controls and DRIVE
Controls to obtain a good white balance in both
low and high light areas.