LG 30FZ1DC Service Manual page 22

PURITY & CONVERGENCE ADJUSTMENT
UP/DOWN ROCKING OF THE YOKE CAUSES
UP/DOWN ROCKING OF THE YOKE
OPPOSITE ROTATION OF RED AND BLUE
CAUSES OPPOSITE ROTATION OF RED
RASTERS
AND BLUE RASTERS
ADJUSTMENT
VIEWING
AREA
GREEN
12. While watching the 6 o'clock positions on the screen, rock the
front of the yoke in a vertical (up/down) direction to converge
the red and blue vertical lines. (Fig upper left)
13. Temporarily place a rubber wedge at the 12 o'clock position
to hold the vertical position or the yoke.
14. Check the 3 o'clock and 9 o'clock areas to confirm that the red
and blue horizontal lines are converged.
If the lines are not converged, slightly offset the vertical tilt of the
yoke (move the rubber wedge if necessary) to equally balance the
convergence error of the horizontal lines at 3 o'clock and 9 o'clock
and the vertical lines at 6 o'clock and 12 o'clock.
15. Place a 1.5 inch piece of glass tape over the rubber foot at
the rear of the 12 o'clock wedge.
16. While watching the 6 o'clock and 12 o'clock areas of the
screen, rock the front of the yoke in the horizontal (left to
right) motion to converge the red and blue horizontal lines.
(Fig. upper right)
ROTATION DIRECTION
RING
OF BOTH TABS
PAIRS
OPPOSITE
4
POLE
OPPOSITE
6
POLE
GREEN
BLUE RED
RED BLUE
GREEN
MOVEMENT OF RED
AND BLUE BEAMS
B
R
SAME
B R
B
R
SAME
B R
LEFT/RIGHT ROCKING OF THE YOKE
LEET/RIGHT ROCKING OF THE YOKE
CAUSES OPPOSITE SIZE CHANGE OF
CAUSES OPPOSITE SIZE CHANGE OF
THE RED AND BLUE RASTERS
THE RED AND BLUE RASTERS
ADJUSTMENT
VIEWING
AREA
GREEN
17. Temporarily place a rubber wedge at the 5 o'clock and 7
o'clock positions to hold the horizontal position of the yoke.
18. Check the 3 o'clock and 9 o'clock areas to confirm that the
red and blue vertical lines are converged. If the lines are not
converged, slightly offset the horizontal tilt of the yoke (move
the temporary rubber wedges if necessary) to equally
balance the convergence error of the horizontal lines at 6
o'clock and 12 o'clock and the vertical lines at 3 o'clock and 9
o'clock.
19. Using a round magnet confirm purity at the center, right and
left sides and corners. See Purity Adjustment Procedure.
20. Reconfirm convergence and apply a 1.5 inch piece of glass
tape over the rubber foot at the rear of the 5 o'clock and the 7
o'clock wedges.
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B
OR
R
B R
OR
B
OR
R
OR
R
B
RED
GREEN
RED
TV
SCREEN