SHARP 21YF30
Manual de Servicio

PURITY ADJUSTMENT
No. Adjustment point 1 PURITY ADJ. Adjustment procedure/conditions 1. Receive the GREEN-ONLY signal. Adjust the beam current to ~700 µ 2. Degauss the CRT enough with the degausing coil. Note: Follow the Job Instruction Sheet to adjust the magnetic field. Vertical Bv: +0.010 mT (0.10 gauss) Horizontal Bh: +0.040 mT (0.40 gauss) 3. Maintain the purity magnet at the zero magnetic field and keep the static convergence roughly adjusted. 4. Observe the points a, b as shown in Fig. 1-1 through the microscope. Adjust the landings to A rank requirement. 5. Orient the raster rotation to 0 eastward. 6. Tighten up the deflection coil screws. » Tightening torque: 108 N ± 20 N (11 kgf ± 2 kgf) 7. 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 700 µA. Note: Set the service mode by JA304 & JA307 (short) then press factory process R/C RGB key to change to RGB mono colour mode. * For the following colours press R/C RGB(Hex 7E) key to change. A
GREEN ONLY BLUE ONLY Signal-colour screen cleared RED ONLY

CONVERGENCE ADJUSTMENT
Waveform and others

21YF30

No. Adjustment point 1 CONVERGENCE ADJ. ( To be done after the purity adjustment.)

Adjustment procedure/conditions 1. Receive the "Crosshatch Pattern" signal. 2. Using the remote controller, call NORMAL mode. Static convergence 1. Turn the 4-pole magnet to a proper opening angle in order to superpose the blue and red colours. 2. Turn the 6-pole magnet to a proper opening angle in order to superpose the green colour over the blue and red colours. Dynamic convergence 1. Adjust the convergence on the fringes of the screen in the following steps. a) Fig. a: Drive the wedge at point "a" and swing the deflection coil upward. b) Fig. b: Drive the wedge at point "b" and "c" and swing the deflection coil downward. c) Fig. c: Drive the "c" wedge deeper and swing the deflection coil rightward. d) Fig. d: Drive the "b" wedge deeper and swing the deflection coil leftward. 2. Fix all the wedges on the CRT and apply glass tape over them. 3. Apply lacquer to the deflection yoke lock screw, magnet unit (purity, 4-pole, 6-pole magnets) and magnet unit lock screw. Finally received the Red-only and Blue-only signals to make sure there is no other colours on the

Waveform and others

BGR B G R
Fig. a

a

b

30mm

Fig. 1-1

30mm

RGB R G B
Fig. b

A

B A=B Fig. 1-2 Rank "A" (on the right of CRT)

B G R

RGB

Fig. c

R G B

BGR

8

Fig. d

B A=B Fig. 1-3 Rank "A" (on the left of CRT) * Press R/C RGB key for 1 second in NORMAL MODE, the colour will change to RGB mono colour mode.

screen.

Wedge "a"
4-pole magnet 6-pole magnet CRT neck

About 100Deg Lacquer Wedge "b"

About 100Deg

Lacquer Purity magnet

20mm

Wedge "c"

8-1

8-2