SHARP 21GF50
Service Manual

PURITY CONVERGENCE ADJUSTMENT
BGR beam current to ~700 µA. ADJ. 2. Using the remote controller, call NORMAL mode.

No. point Adjusting procedure/conditions Waveform and others

PURITY ADJ. GREEN-ONLY Adjust 1 CONVERGENC 1. Receive the "Crosshatch Pattern" signal.

2. Degauss CRT enough with the degausing coil. ( To be done

a Note: Follow Job Instruction Sheet to adb after the purity Static convergence B

Vertical Bv: -0.010 mT (-0.10 gauss) gle in order to superpose the blue and red colHorizontal Bh: +0.040 mT (0.40 gauss) ours. (Reference: page E-13) 2. Turn the 6-pole magnet to a proper opening anFig. 5-1 Fig. 4-1 RGB 50mm

G just magnetic field. adjustment. 1. Turn the 4-pole magnet to a proper opening anR

3. Maintain purity magnet at zero magnetic gle in order to superpose the green colour over

field keep static convergence roughly the blue and red colours. adjusted.

4. Observe the points a, b as shown in Fig. 4-1 Dynamic convergence G

R

through microscope. landing to 1. Adjust convergence on fringes of the B A rank requirements. A screen in the following steps. Fig. 5-2
B

5. Orient raster rotation to 0 eastward. a) Fig. 5-1: Drive the wedge at point "a" and swing 6. Tighten up screws. the deflection coil upward.

7. Make sure CRT corners landing meet A and swing the deflection coil downward. G

» Tightening torque: 108 20 N (11 ± 2 kgf) b) Fig. 5-2: Drive the wedge at points "b" and "c" RGB B

rank requirements. If not, stick magnet sheet c) Fig. 5-3: Drive the "c" wedge deeper and swing R to correct it. the deflection coil rightward. Note: This adjustment must be done after d) Fig. 5-4: Drive the "b" wedge deeper and

A = B

Note: Set the service mode by TP1001 & tape over them. BGR (on right of the CRT)
R

warming up unit for 30 minutes or Fig. 4-2 swing the deflection coil leftward. longer with a beam current over 700 2. Fix all wedges on the CRT and apply glass Fig. 5-3 Rank "A" µA. TP1002 (short) then press factory proc3. Apply lacquer to the deflection yoke lock screw, G

ess R/C key change to RGB magnet unit (purity, 4-pole, 6-pole magnets) and B mono colour mode. magnet unit lock screw.

* For the following colours press R/C RGB key to

9
B Wedge "a"
Fig. 4-3

change. A Finally received the Red-only and Blue-only signals to make sure there is no other colours on the Fig. 5-4

GREEN BLUE RED screen. ONLY

Signal-colour screen cleared A = B

About 100Deg Lacquer Wedge "c" * Press R/C RGB key for 1 sec"b"

Rank "A" (on left of the CRT)

ond in NORMAL MODE, the Fig. 5-5 colour will change to RGB mono colour mode. 4-pole magnet Text R.G.Cy � Key can be 6-pole magnet directly use change to other colours screen.

CRT neck

20mm Lacquer

Purity magnet

Fig. 5-6

21GF30 21GF50

E-16 E-17