Zenith H19F34DT Series, Руководство по обслуживанию

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SR25-3828VD0171B
3-6
CL - SERVICING
PRELIMINARY SETUP
1. Allow the receiver to warm up for 15 to 20 minutes.
2. Degauss the CRT.
3. Connect a crosshatch generator to the receiver and
“rough in” the static (center) convergence. Follow
the Convergence Procedure.
4. Adjust for best focus.
PURITY ADJUSTMENT
1. Purity tab positioning. Set the 2 pole purity tabs
together in the 3 or 9 o’clock positions and the 4-
and 6-pole purity tabs together in the 12 or 6 o’clock
positions.
2. Move yoke to the maximum forward funnel position.
3. Next, switch the crosshatch generator to a red field.
4. Pull the yoke toward the rear of the CRT neck, keep-
ing it centered, until a red raster is displayed.
5. If the red raster is not displayed as a pure red field,
adjust the 2-pole purity tabs until a pure field is
obtained.
6. Check for proper yoke tilt setting.
CONVERGENCE ADJUSTMENT
1. Release locking assembly.
2. Connect crosshatch generator to the receiver and
adjust static (center) convergence as follows:
a. Adjust the 4-pole static control by moving the
two tabs separately to converge the red and blue
lines horizontally. Move the two tabs together
around the neck of the CRT (in a 45° arc) from the
top-dead-center position to converge the red and
blue lines vertically.
b. After the 4-pole control has been adjusted to
superimpose the red and blue lines on top of one
another. Use the 6-pole static adjustment to place
the converged red and blue lines over the green
line. Move the two tabs together around the neck
of the CRT (in a 30° arc) from the top-dead-center
position to move the lines vertically. Adjusting the
two tabs separately will move the converged beam
to the left or right. Using a crosshatch generator
capable of producing individual fields, adjust the
generator to produce a red field. Use the purity
tabs to center a red stripe.
PURITY & CONVERGENCE SETUP PROCEDURE
SERVICE ADJUSTMENTS (continued)
Yoke's Glass Cloth Tape
Wedges' Adhesive Tape (3)
Rubber Wedges (3)
Deflection Yoke
Purity & Convergence
Magnet Assembly Unit
6 Pole
Purity Magnet
4 Pole
Ring
Pairs
6 Pole
Convergence
R&B over G
Convergence
R over B
4 Pole
Rotation direction
of Both Tabs
Opposite
Opposite
Same
Same
Movement of Red
and Blue Beams
B
B B
R R
B B R R
B
R
R
OR
OR
OR
B
B
R
R
OR
CRT Ring Location Purity
Adjust Tabs Beam Movement
for Convergence