Alignments
8.
8.
Alignments
Index of this chapter:
8.1 General Alignment Conditions
8.2 Hardware Alignments
8.3 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
Ω
; 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
0231
0212
C
16532016_003.eps
120401
A
D
B
5445
LOT
Focus
Screen
VG2
5520
2403
0217
ComPair
1004
1002
1000 (TUNER)
9631
9641
SDM
0231
7602
0V Ref.
CL 06532130_014.eps
131000
V
CUTOFF
[V
DC
]
max.
CUT-OFF VOLTAGE
Screen size
Cut-off [V]
13V, 14”, 14RF, 15RF, 17”, 19V, 20”
140 ± 4
21” (L01S)
150 ± 4
21” (L01L), 20RF, 21RF, 24WS,
25BLD, 25HF, 28 BLD, 28WS
125 ± 4
25V, 25BLS, 25RF, 27V, 28BLS, 29”,
29RF, 32V, 33”, 32WS, 35V
145 ± 10
CL 16532008_0
5
8
2
208
01
