Sharp 21HF2-SS, Service Manual

Page: 17 / 73

21HF2-SS
3 – 14
2. PURITY ADJUSTMENT
No. Adjustment point Adjustment condition/procedure Waveform or others
1 PURITY ADJ. 1. Receive the GREEN-ONLY signal. Adjust the beam current to
~700
μ
A.
2. Degauss the CRT enough with the degausing coil.
NOTE: Follow the Job Instruction Sheet to adjust the magnetic
field.
(Reference: page 3-12)
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 micro
scope. Adjust the landings to the A rank requirement.
5. Orient the raster rotation to 0 eastward..
6. Tighten up the deflection coil screws .
•
Tightening torque: 108 20 N (11
±
2 kgf)
7. Make sure the CRT corners landing meet the A rank require
ments. If not, stick the magnet sheet to correct it.
NOTE: Note: This adjustment must be done after warming up the
unit for 30 minutes or longer with a beam current over
700
μ
A.
NOTE: 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.
*Press R/C RGB key for 1 second in NORMAL
MODE, the colour will change to RGB mono
colour mode.
S ignal-colour
s creen cleared
G R E E N
ONLY
B LUE
ONLY
R E D
ONLY
a
b
A
B
A
30mm 30mm
B
A = B
A = B
R ank "A"
(on the right of the C R T )
R ank "A"
(on the left of the C R T )
F ig. 1-1
F ig. 1-2
F ig. 1-3