Toshiba 27A50, Service Manual

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GENERAL ADJUSTMENTS
SPECIFIC INFORMATIONS
WARNING: BEFORE SERVICING THIS CHASSIS, READ THE “X-RAY RADIATION PRECAUTION”, “SAFETY PRECAU-
TION” AND “PRODUCT SAFETY NOTICE” ON PAGE 3 OF THIS MANUAL.
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The following adjustments should be made when a complete realignment is required or a new picture tube is installed.
Perform the adjustments in order as follows :
1. Color Purity
2. Convergence
3. White Balance
Note: The PURITY/CONVERGENCE MAGNET assembly and rubber wedges need mechanical positioning.
Refer to figure 1.
Mounting position of the purity magnet assembly should fit to same position as old one because slightly difference to
the position depend on a kind of tube.
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There are no adjustment of purity and convergence in some picture tube (unified with purity magnet).
COLOR PURITY ADJUSTMENT
NOTE : Before attempting any purity adjustments, the re-
ceiver should be operated for at least fifteen min-
utes.
1. Evenly degauss the entire screen.
2. Set the CONTRAST and BRIGHTNESS Controls to
the maximum.
3. Display built-in green raster using the TEST SIGNAL
SELECTION function.
4. Loosen the clamp screw holding the deflection yoke
(and remove the Rubber Wedges).
5. Slide the yoke forward or backward to provide vertical
green belt (zone) in the picture screen.
6. Rotate and spread the tabs of the purity magnet (See
figure 4.) around the neck of the picture tube until the
green belt is in the center of the screen. At the same
time, center the raster vertically by adjusting the mag-
net as shown below.
7. Move the yoke slowly forward or backward until a uni-
form green screen is obtained. Tighten the clamp screw
of the yoke temporarily.
8. Check the purity of the red and blue raster.
9. Put four wedges into the space between the picture
tube and the yoke to hold the yoke in the adjusted
position. (See figure 2.)
Do not tilt the yoke by excessive insertion of the wedge.
10. Remove cover paper of wedge and stick wedges on
the tube to fix the yoke in the adjusted position.
Fix the wedges with glass cloth tapes.
Green Belt
DEFLECTION YOKE
1-5/8”
PURITY/
CONV.
MAGNET
Xv Coil
RUBBER WEDGES
DEFLECTION
YOKE
Figure 2.
Figure 1.
(FOR 35", 36")
Adhesive