Alignments - Philips L01.2A AB Service Manual

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.
• Figures can deviate slightly from the actual situation, due
to different set executions or software versions.
8.1 General Alignment Conditions
Perform all electrical adjustments under the following
conditions:
• AC voltage and frequency: according to country's
standard.
• Connect the set to the AC power 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 MΩ; Ci < 2.5 pF.
• Use an isolated trimmer / screwdriver to perform the
alignments.
8.2 Hardware Alignments
0217
D
ComPair
7602
2403
1004
A
Figure 8-1
0231
C 0212
5520
5445
B
LOT
Focus
Screen
VG2
16532016_003.eps
120401
Alignments L01.2A AB
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
alignment. Adjust the V
potentiometer (see Fig. 8-1) on the LOT to the correct
value (see table below).
11. Restore BRIGHTNESS and CONTRAST to normal (= 31).
max.
0V Ref.
Figure 8-2
Screen size
13V, 14", 14RF, 15RF, 17", 19V, 20"
21" (L01S)
21" (L01L), 20RF, 21RF, 24WS,
25BLD, 25HF, 28 BLD, 28WS
25V, 25BLS, 25RF, 27V, 28BLS, 29",
29RF, 32V, 33", 32WS, 35V
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. EN 41
value for the
DC
of this gun with the SCREEN
cutoff
V [V ]
CUTOFF DC
CL 06532130_014.eps
CUT-OFF VOLTAGE
Cut-off [V]
140 ± 4
150 ± 4
125 ± 4
145 ± 10
CL 16532008_058.pdf
131000
220801