Alignments
GB 49
L01.1E
8.
8. Alignments
Index of this chapter:
1. General Alignment Conditions
2. Hardware Alignments
3. Software Alignments and Settings
Note:
The Service Default Mode (SDM) and Service
Alignment Mode (SAM) are described in chapter 5. Menu
navigation is done with the 'CURSOR UP, DOWN, LEFT or
RIGHT' keys of the remote control transmitter.
8.1
General Alignment Conditions
Perform all electrical adjustments under the following
conditions:
•
Mains voltage and frequency: according to country’s
standard.
•
Connect the set to the Mains via an isolation transformer.
•
Allow the set to warm up for approximately 20 minutes.
•
Measure the voltages and waveforms in relation to
chassis ground (with the exception of the voltages on the
primary side of the power supply). Never use the cooling
fins/plates as ground.
•
Test probe: Ri > 10 M
W
; Ci < 2.5 pF.
•
Use an
isolated
trimmer/screwdriver to perform the
alignments.
8.2
Hardware Alignments
Figure 8-1
8.2.1
Vg2 Adjustment
1. Activate the SAM.
2. Go to the WHITE TONE sub menu.
3. Set the values of NORMAL RED, GREEN and BLUE to
40.
4. Go, via the MENU key, to the normal user menu and set
–
CONTRAST to zero.
–
BRIGHTNESS to minimum (OSD just visible in a
dark room).
5. Return to the SAM via the MENU key.
6. Connect the RF output of a pattern generator to the
antenna input. Test pattern is a 'black' picture (blank
screen on CRT
without
any OSD info).
7. Set the channel of the oscilloscope to 50 V/div and the
time base to 0.2 ms (external triggering on the vertical
pulse).
8. Ground the scope at the CRT panel and connect a 10:1
probe to one of the cathodes of the picture tube socket
(see diagram B).
9. Measure the cut off pulse during first full line after the
frame blanking (see Fig. 8-2). You will see two pulses,
one being the cut off pulse and the other being the white
drive pulse. Choose the one with the lowest value, this is
the cut off pulse.
10. Select the cathode with the highest V
DC
value for the
alignment. Adjust the V
cutoff
of this gun with the SCREEN
potentiometer (see Fig. 8-1) on the LOT to the correct
value (see table below).
11. Restore BRIGHTNESS and CONTRAST to normal (=
31).
Figure 8-2
Figure 8-3
8.2.2
Focusing
1. Tune the set to a circle or crosshatch test pattern (use an
external video pattern generator).
2. Choose picture mode NATURAL (or MOVIES) with the
‘SMART PICTURE’ button on the remote control
transmitter.
3. Adjust the FOCUS potentiometer (see Fig. 8-1) until the
vertical lines at 2/3 from east and west, at the height of
the centreline, are of minimum width without visible haze.
8.3
Software Alignments and Settings
Enter the Service Alignment Mode (see chapter 5). The SAM
menu will now appear on the screen.
Select one of the following alignments:
1. Options
2. Tuner
3. White Tone
4. Geometry
5. Audio
0231
0212
C
16532008_038.eps
160501
A
D
B
5445
LOT
Focus
Screen
VG2
5520
0240
0267
0268
7602
ComPair
1004
1002
1000 (TUNER)
9631
9641
SDM
0231
0V Ref.
CL 06532130_014.eps
131000
V
CUTOFF
[V
DC
]
max.
&872))92/7$*(//$5*(
6FUHHQVL]H
&XWRII>9@
´
%J
´´´
´´´´
%J%"
CL 16532008_056.pdf
220501
