14Gt15 - Sharp 14GT15 Service Manual

14GT15

14GT20
No. Adjusting point
1 PURITY ADJ.
PURITY ADJUSTMENT
Adjusting procedure/conditions
1. Receive the GREEN-ONLY signal. Adjust the
beam current to about 500 A.
2. Maintain the purity magnet at the zero magnetic
field and keep the static convergence roughly
adjusted.
3. Observe the points a, b as shown in Fig. 4-1
through the microscope. Adjust the landing to the
A rank requirements.
4. Orient the raster rotation to 0 eastward.
5. Tighten up the deflection coil screws.
» Tightening torque: 108
6. Make sure the CRT corners landing meet the A
rank requirements. If not, stick the magnet sheet
to correct it.
Note: This adjustment must be done after
warming up the unit for 30 minutes or
longer with a beam current over 500 A.
20 N (11 2 kgf)
12
Waveform and others
a
b
Fig. 4-1
A
B
A = B
Fig. 4-2
Rank "A"
(on the right of the CRT)
A
B
A = B
Fig. 4-3
Rank "A"
(on the left of the CRT)