Samsung CKA4217L Service Manual page 25

5-3-9 Color Purity Adjustment
Color purity is the absence of undesired color.
Conspicuous mislanding (unexpected color in a
uniform field) within the display area shall not be
visible at a distance of 50 cm from the CRT
surface.
CONDITIONS
Orientation: Monitor facing east
Scanning frequency: 53.7 kHz/85 Hz (15")
43.8 kHz/85 Hz (14")
Display image: White flat field
Luminance: Cutoff point at the center
of the display area
Caution: Color purity adjustments should only
be attempted by qualified personnel.
PROCEDURE
For trained and experienced service technicians
only.
Use the following procedure to correct minor
color purity problems:
1. Make sure the display is not affected by
external magnetic fields. Use an external
degaussing coil to neutralize magnetic fields
which may be affecting color purity.
2. Very carefully break the glue seal between the
2-pole purity convergence magnets (PCM), the
band and the spacer (see Figure 5-9).
CKA42*7L/5227L
3. Make sure the spacing between the PCM
assembly and the CRT stem is
22.5 mm ± 1 mm.
4. Display a red pattern over the entire display
area.
5. Adjust the Purity Magnet Rings on the PCM
assembly to display a pure green pattern.
(Optimal setting: x = x = 0.310 ± 0.015,
y = 0.592 ± 0.015)
6. Repeat steps 4 and 5 using a red pattern and
then again, using a blue pattern.
Table 5-3. Color Purity Tolerances
Red: x = 0.625 ± 0.015
Green: x = 0.310 ± 0.015
Blue: x = 0.150 ± 0.015
(For 9300°K white color adjustment:
x = 0.283 ± 0.02, y = 0.298 ± 0.02)
7. When you have the PCMs properly adjusted,
carefully gule them together with Locktite to
prevent their movement during shipping.
5 Alignment and Adjustments
y = 0.340 ± 0.015
y = 0.592 ± 0.015
y = 0.063 ± 0.015
5-9