Service manual
8
14A1-RU
14A2-RU
8-2
8-1
CRT CUT-OFF, BACKGROUND AND SUB-CONTRAST ADJUSTMENT
No. Adjusting point Adjusting procedure/conditions Waveform and others
CRT CUTOFF
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 µA.
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 SERV-
ICE MODE
ADJ. (I2C BUS
CONTROL)
3 Refer to Page 6.
# 7500° K X : 0.300
Y : 0.310
( MINOLTA COLOUR ANALYZER
CA-100)
*NOTE: Above DATA 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"DATA-5
DRI-BW="DRI-BS" DATA-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 800µA)
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 (MINOLTA CA-100) by reducing
LUMINATE 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: This 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
DATA, after finishing DRI-BS and DRI-GS DATA
ADJUSTMENT.
DRI-RW=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 Waveform and others
CONVERGENC
ADJ.
( To be done
after the purity
adjustment.
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 an-
gle in order to superpose the blue and red col-
ours.
2. Turn 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 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 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