SHARP 14DT20
Service Manual

14GT15 14GT20

PURITY ADJUSTMENT
No. Adjusting point 1 PURITY ADJ. Adjusting procedure/conditions 1. Receive the GREEN-ONLY signal. Adjust the beam current to about 500 µA. 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 ± 20 N (11 ± 2 kgf) 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 µA. 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)

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