Nokia 447PRO, Service Manual

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447R
30
7.7. Convergence
Reduce first the convergence error in the middle of the screen to minimum using static adjustments.
After the convergence is faultless in the middle of the tube, use dynamic adjustments to eliminate
the error in the edges of the tube.
Static adjustments affects the whole picture area:
-
Magnet ring set on the tube neck (hori vertical)
Dynamic adjustments affects a part of the picture area:
-
Deflection yoke trimmers.
7.7.1. Measuring Conditions
- Adjust convergence with 91.15 kHz (NCE642) line frequency.
- Make sure that focus is correctly set at the mid-point between the screen center and the edge of
the picture.
- Use white crosshatch test pattern with circle.
- Adjust to near the maximum and reduce until the background disappears.
A
B
0.5 0
Red
Green
Blue
0.5
0.5 0 0.5
X
Y
0.5 0 0.5
0.5 0 0.5
7.7.2. Convergence Measuring Gauge CM7AR
The use of the Klein CM7AR Convergence Gauge has been explained here but other types of
gauges can be used as well.
Check that the adjusting knobs (A & B) are set to zero.
-- Place the gauge on the line with marking
Y up
upwards when measuring horizontal line.
-- Place the gauge on the line with marking X up upwards when measuring vertical line.
-- If the line has convergence error, the line in the window seems to be broken.
-- Use knobs A and B to adjust the line continuous.
-- If the readings are on the opposite side of zero, the convergence error is A+B (e.g. 0.2 + 0.1
= 0.3).
-- If the readings are on the same side of zero, the convergence error is equal to A if A > B or
B if B > A
7.7.3. Static Convergence
The magnet rings has been set to the optimum in the factory. Readjustment is necessary only in
case the adjusting magnets have been accidentally moved.
1
Adjust R and B vertically one on the other with 4 pole magnet rings, use red/blue crosshatch.
2
Adjust R and B horizontally one on the other with 4 pole magnet rings, use red/blue crosshatch.
3
Adjust Lilac (R and B) vertically onto the green with 6 pole magnet rings, use white crosshatch.
4
Adjust Lilac (R and B) horizontally onto the green with 6 pole magnet rings, use white crosshatch.
Lock the rings with paint.
6 pole magnet rings
R
G
B
SMH
1
2
Purity magnet rings.
Do not adjust !
Sliding two ring tobs toward
or away from each other
Rotating both rings together
4
4
3
4 pole magnet rings
3
2
1
4 3
2 1