Sylvania 6420FF Service Manual page 19

20" color television
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12. Cut-off Adjustment
Purpose: To adjust the beam current of R, G, B, and
screen voltage.
Symptom of Misadjustment: White color may be
reddish, greenish or bluish.
Test Point
Adj. Point
Screen-Control
---
[CH o / p]
buttons
Tape
M. EQ.
Pattern
---
Generator
Figure
Pattern Generator
Ext. Input
Note: Screen Control FBT --- Main CBA
FBT = Fly Back Transformer
Use service remote control unit
1. Degauss the CRT and allow CRT to operate for 20
minutes before starting the alignment.
2. Input the Black Raster Signal from RF Input.
3. Enter the Service mode. (See page 5-1.)
4. Press [VOL p] button on the service remote
control unit and select "C/D" mode. (Display
changes "C/D," "7F," "LANGUAGE," "ACCESS
CODE," "SOUND TYPE," "VIDEO TONE," "FM-
MODE," "V-OUT," "VIDEO," "AV MEMO," "STABLE
SOUND," "FILTER," "1000," "YUV MEMORY," "NO
SIG
BRT,"
"A-MUTE
cyclically when [VOL p] button is pressed.) then
press "1." The display will momentarily show "CUT
OFF R" (R= Red). Now there should be a
horizontal line across the center of the picture
tube. If needed gradually turn the screen control
on the flyback, clockwise until the horizontal line
appears. Adjust the Red Cut off by pressing [CH o
/ p] buttons. Proceed to Step 5 when the Red Cut
off adjustment is done.
5. Press [2] button. The display will momentarily
show "CUT OFF G" (G = Green). Adjust the Green
Mode
Input
Black
RF
Raster
Spec.
See Reference
Notes below.
Fig. 2
POL,"
and
"V-MENU"
Cut off by pressing [CH o / p] buttons. Proceed to
step 6 when the Green Cut off adjustment is done.
6. Press [3] button. The display will momentarily
show "CUT OFF B" (B = Blue). Adjust the Blue cut
off by pressing [CH o / p] buttons. When done
with steps 4, 5 and 6 the horizontal line should be
pure white if not, then attempt the Cut off
adjustment again.
13. White Balance Adjustment
Purpose: To mix red, green and blue beams correctly
for pure white.
Symptom of Misadjustment: White becomes bluish
or reddish.
Test Point
Adj. Point
[CH o / p]
Screen
buttons
Tape
M. EQ.
Pattern
---
Generator,
Color analyzer
Note: Use service remote control unit
1. Operate the unit more than 20 minutes.
2. Face the unit to east. Degauss the CRT using
Degaussing Coil.
3. Input the White Raster (APL 100%).
4. Set the color analyzer to the CHROMA mode and
after zero point calibration, bring the optical
receptor to the center on the tube surface (CRT).
5. Enter the Service mode. (See page 5-1.) Press
[VOL p] button on the service remote control unit
and select "C/D" mode. (Display changes "C/D,"
"7F," "LANGUAGE," "ACCESS CODE," "SOUND
TYPE," "VIDEO TONE," "FM-MODE," "V-OUT,"
"VIDEO,"
"AV
"FILTER," "1000," "YUV MEMORY," "NO SIG BRT,"
"A-MUTE POL," and "V-MENU" cyclically when
[VOL p] button is pressed.) then Press [8] button
on the service remote control Unit.
5-5
Mode
Input
White
Raster
RF
(APL
100%)
Spec.
See below
Figure
Color Analyzer
Fig. 3
MEMO,"
"STABLE
SOUND,"
L3300EA

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