Grey Scale; The Most Dominant Colour; Low Light; High Light - Nokia 446PRO Service Manual

7.4. Grey Scale

The grey scale is adjusted for 9300K colour temperature.
Activate Service Mode in 91.376 kHz/85 Hz (GTF642).

7.4.1. The Most Dominant Colour

The most dominant colour has been marked in a label on the deflection yoke.
It may not be correct if tube or SMH card has been changed. In that case judge
the most dominant colour from the tone of the picture after you have made the
following adjustments.
1) Select 91.376/85 (GTF642) black test pattern.
2) Set to maximum and
3) Set Blacklevel adjustment RED/GREEN/BLUE Black Level to (step 33)
4) Set RED/GREEN/BLUE Amp (step 33) menu and G2 menu adjustments to
center (step130).
5) Place the probe of the colour analyzer in the middle of the screen and
adjust with G2 trimmer until the picture illuminance is 3±1.0 cdm

7.4.2. Low Light

1) Select 91.376/85 (GTF642) black test pattern.
2) Adjust picture illuminance to 1.0 cdm
3) Adjust the in servicemenu to the minimum.
4) Adjust the colour coordinates to (9300K)
x = 0.283±0.010
y = 0.297±0.010
with RED/GREEN/BLUE Black Level adjustments.
Do not adjust the most dominant colour.
During the adjustment check if brightness is chancing over tolerance, when
needed adjust it back. If Y--- and X---values are getting too far from ideal val-
ues, you have chosen wrong MOST DOMINANT COLOUR. Check the domi-
nant colour again according to the instructions.
5) Set to the maximum and check that the illuminance is still 3±1.0 cdm
not, adjust with G2 in service menu.
6) Adjust picture illuminance to 1.0 cdm
check the colour coordinates.

7.4.3. High Light

1) Select 91.376/85 (GTF642) black test pattern.
2) Adjust with the picture illuminance to 1±0.1 cdm
3) Select 91.376/85 (GTF642) window test pattern.
4) Adjust with the picture illuminance in the window to 100±5 cdm
5) Adjust with RED/BLUE Amp the colour coordinates in the window to
x = 0.283±0.003
y = 0.297±0.003
Check after adjustment that the illuminance reading is in limits.
6) Back to low light step 4) and check colour coordinates.

7.5. Maximum/Minimum Contrast

1) Set to the maximum.
2) Adjust with the picture illuminance outside window to 1.0 cdm
3) Adjust illuminance in the window to 140±5 cdm
MAX CONTRAST.
4) Set to the minimum.
5) Adjust the minimum illuminance in the window to 5 ± 1 cdm
with MIN CONTRAST.
6) Exit from service mode.

7.6. Focus

1) Select 91.376/85 (GTF642) crosshatch test pattern
2) Set to the maximum and adjust
3) Adjust the sharpness with FOCUS H and FOCUS V to optimum
4) Adjust until the background is invisible
5) Select focus test pattern. Check that all letters are clearly visible.
to minimum.
- -2
(Nits)with
2
(Nits)with
- -2
to 70 % (background faintly visible).
446F
2
(Nits)
in servicemenu.
2
in servicemenu and
2
(Nits).
2
(Nits)
- -2
(Nits).
(Nits) with
- -2
(Nits)
FOCUS V
FOCUS H
Left side view
. If
of the chassis
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