Sharp 14A1-RU, Service Manual

Page: 8 / 42

8
14A1-RU
14A2-RU
8-2
8-1
CRT CUT
-OFF
, BACKGROUND
AND SUB-CONTRAST
ADJUSTMENT
No.
Adjusting point
Adjusting procedure/conditions
W
aveform and others
CRT CUT
OFF
ADJUSTMENT (I
2
C BUS
CONTROL)
1
.
Switch
TV to VIDEO mode,BLUE BACK OFF
, with
NO VIDEO signal.
2.
Press R/C to set Picture Normal condition.
3
.
Connect the oscilloscope to Red OUT from IC801.(TP851)
Range
: 1 V/Div (DC)
Sweep
: 5 msec/Div
4
.
Adjust SCREEN VR ,so that the tip of signal reach 3.0 Vdc + 0.1 Vdc.
1
1 V
3.0Vdc 0
Maximum beam check
1.
Receive the "Monoscope Pattern" signal.
2.
Press R/C to set Picture NORMAL condition.
3.
Connect the DC miliammeter between
TP603 (+)
and TP602
(–).
(Full Scale: 3 mA Range)
4.
Beam current must be within 800
±
100
µ
A.
4
SUB-BRIGHT
-
NESS ADJUSMENT (I
2
C BUS
CONTROL)
1
.
Call " SUB-BRI" in service mode. (Receive Cross- hatch pattern with 5 black level windows)
2.
Adjust the " SUB BRIGHT " bus data in order that the line 1, 2 and 3 have the same darkness wherelse line 4 is slightly brighter than line 1, 2 and 3 and finally line 5 will be the brighter than line 4.
2
1, 2, 3 are in same black level.
1 2 3 4 5
WHITE BAL- ANCE SER
V
-
ICE MODE ADJ. (I2C BUS CONTROL)
3
Refer to Page 6. # 7500
°
K
X
: 0.300
Y : 0.310
( MINOL
T
A
COLOUR
ANAL
YZER
CA-100) *NOTE:
Above DA
T
A
can be UP/
DOWN by volume key
.
LOW
HIGH
14"
10cd/m2
200cd/m2
20"/21"
10cd/m2
120cd/m2
* 7500
°
K
DRI-GW="DRI-GS"DA
T
A-5
DRI-BW="DRI-BS" DA
T
A-5
1. Receive the "Monoscope Pattern" signal. 2. Press R/C to set Picture NORMAL condition. 3. Connect the DC miliammeter between the
TP
602
( - )
TP
603 ( + ).
4. Check Beam current should be around 800
µ
A)
5. Set it to service mode and adjust the DRI-GS, &
DRI-BS data to have a colour temperature of 7500
°
K ( white ).
6.
Receive "WHITE" pattern, WITH BURST signal, and set BRIGHTNESS
Y
by generator
, to ** 10
cd/m2 (MINOL
T
A
CA-100) by reducing
LUMINA
TE Y
signal.
7.
Adjust "CUT
-R" & "CUT
-G" to get 7,500.
Then go
back NORMAL mode (HIGH BRIGHT**) to check colour temperature. If out of range, back to (1). Note:
T
h
is
adjustment must be done after
warming up the unit for 30 minutes or longer with a beam current over 500
µ
A.
*
ADJUST
DRI-GC/GW
, DRI-BC/BW as following
DA
T
A, after finishing DRI-BS and DRI-GS DA
T
A
ADJUSTMENT
.
DRI-R
W=32 (FIXED), DRI-GW="DRI-GS"-7*,
DRI-BW="DRI-BS"-7*DRI-RC=25*, DRI- BC="DRI-BS", DRI-GC="DRI-GS"-7*
CONVERGENCE ADJUSTMENT
No.
Adjusting point
Adjusting procedure/conditions
W
aveform and others
CONVERGENC ADJ. ( T
o
be done
after the purity adjustment.
1.
Receive the "Crosshatch Pattern" signal.
2.
Using the remote controller
, call NORMAL
mode.
ST
A
TIC CONVERGENCE
1.
T
urn the 4-pole magnet to a proper opening an-
gle in order to superpose the blue and red col- ours.
2.
T
urn 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. 5-1: Drive the wedge at point "a" and swing the deflection coil upward.
b)
Fig. 5-2: Drive the wedge at points "b" and "c" and swing the deflection coil downward.
c)
Fig. 5-3: Drive the "c" wedge deeper and swing the deflection coil rightward.
d
)
Fig. 5-4: Drive the "b" wedge deeper and swing the deflection coil leftward.
2.
Fix all the wedges on the CR
T
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 sig- nals to make sure there is no other colours on the screen.
1
RGB
BGR
R G B
R G B
B G R
B G R
RGB BGR
Lacquer
Wedge "a"
Wedge "b"
Wedge "c"
About 100
°
About 100
°
4-pole magnet
6-pole magnet
CRT neck
40cm
Lacquer
Purity magnet
Fig. 5-1
Fig. 5-2 Fig. 5-3 Fig. 5-4