Sharp 14U10, Service Manual

Page: 7 / 44

14U10/15
14U20/25
7
7-1
7-2
CONVERGENCE ADJUSTMENT
No.
Adjusment point
Conditions/Adjusting pr
ocedure
W
a
vef
orm or other
s
CONVERGENC ADJ. (
T
o
be done
after the purity adjustment.)
1
RGB
BGR
R G B
R G B
B G R
B G R
R G B
BGR
Lacquer
Wedge "a"
Wedge "b"
Wedge "c"
About 100 Deg
About 100 Deg
4-pole magnet
6-pole magnet
CRT neck
20cm
40cm(14")
(21")
Lacquer
Purity magnet
Fig. a
Fig. b Fig. c Fig. d
1.
Receive the "Crosshatch Pattern" signal.
2.
Using the remote controller
, call NORMAL mode
.
ST
A
TIC CONVERGENCE
1.
T
u
rn
the 4-pole magnet to a proper opening an-
gle in order to superpose the blue and red col- ours.
2.
T
u
rn
the 6-pole magnet to a proper opening an-
gle 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:
Dr
iv
e the w
edge at point "a" and s
wing
the deflection coil upward.
b)
Fig.
b:
Dr
iv
e the w
edge at points "b" and "c"
and swing the deflection coil downward.
c)
Fig.
c:
Dr
iv
e the "c" w
edge deeper and s
wing
the deflection coil rightward.
d)
Fig.
d:
Dr
iv
e the "b" w
edge deeper and s
wing
the deflection coil leftward.
2.
Fix all the w
edges on the CR
T and apply glass
tape over them.
3.
Apply lacquer to the deflection y
ok
e loc
k scre
w
,
magnet unit (pur
ity
, 4-pole
, 6-pole magnets) and
magnet unit loc
k scre
w
.
Finally received the Red-only and Blue-only sig- nals to make sure there is no other colours on the screen.
PURITY ADJUSTMENT
No.
Adjusment point
Conditions/Adjusting pr
ocedure
W
a
vef
orm or other
s
PURITY ADJ
.
1
.
Receiv
e the GREEN-ONL
Y signal.
Adjust the
beam current to ~ 500
µ
A.
2.
Maintain the purity magnet at the zero magnetic field and keep the static convergence roughly adjusted.
3
.
Obser
v
e
the points a, b
, as sho
wn in Fig.
1-1
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 scre
ws
.
»
Tightening
torque:
108
±
20 N (11
±
2 kgf)
6.
Mak
e sure the CR
T cor
ners 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
µ
A.
1
a
b
A
B
A
B
A = B A = B
Rank "A"
(On the right of the CRT)
Rank "A"
(On the left of the CRT)
Fig. 1-1
Fig. 1-2
Fig. 1-3