Philips S42AX-YD04 Service Manual page 68

EN 68 8. SDI PDP 2K7
8.2 Alignments 42" HD W2
8.2.1 Quick Check
For a quick check on the correct Y-main waveform alignment,
use the following method: Check the position of the potmeter
VR5003 [1]. If it points in this direction [2], use a trimmer [3] to
return it to the correct position [1].
Figure 8-13 Correct position of VR5003 [1]
Figure 8-14 Wrong position of VR5003 [2]
Figure 8-15 Changing of VR5003 [3]
Alignments
8.2.2
H_16870_074.eps
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H_16870_075.eps
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H_16870_076.eps
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For Reference Only
If the quick check does not solve the issue, perform the
following alignments:
1. Set the pattern to "Full White":
• Place jumper CN2013 (pins 3 and 4) on the Logic
Board
• The display starts showing a cycle of different patterns.
At the moment the "full white" pattern is visible, remove
the jumper. Now the display shows a continuous full
white pattern.
To restart the cycle of different patterns, replace the
jumper.
2. Check the waveform using an oscilloscope (see figures
"Adjusting waveforms - 42" HD W2").
• Trigger via V_TOGG on the LOGIC Board (see figure
"Logic PWB 42" HD W2").
• Connect the "CN5411" test point, located at the bottom
of the Y-buffer PWB, to the other channel, and then
check the first SubField (SF) waveform of one TV-
Field.
• Check the waveform by adjusting the "horizontal
division" of the oscilloscope.
• Check the Reset waveform when the V_TOGG level is
changed.
3. Adjust the waveform of the rising ramp with VR5001.
4. Adjust the waveform of the falling ramp with VR5002.
Figure 8-16 Logic PWB - 42" HD W2
V-TOGG
JUMPER
CN2013
PIN 3 & 4
H_16870_072.eps
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