Philips S37SD-YD02 Service Manual page 65

8.7 Alignments 50" HD v3
1. Get Pattern to be Full White.
2. Adjust Vsch to 25 V by using VR5901_VSC_h (Vsc_h
should be connected to "+" unit of DMM).
3. Check the waveform using Oscilloscope.
• Triggering through V_TOGG of LOGIC Board.
• Connect the OUT 4 Test Point at the centre of Y_buffer
to other channel, and then check the first SF operating
waveform of 1TV-Field.
• Check the waveform as before by adjusting Horizontal
Division. Check the Reset waveform when the
V_TOGG Level is changed.
• Set the Rising Ramp Flat Time to 50 µs by adjusting
VR5000. GND maintenance section should be
Adjust VR5000 to set the time of
Yrr( Rising Ramp) 50 µs
Adjust VR5001 to set the time of Yfr
(Falling Ramp_1st) 35 µs
(V)
50V/div.
DC=0V
Figure 8-38 Rising ramp
Figure 8-37 TCP ramp waveform inclination adjustment (Y-Board)
40V
20ms/div.
(t)
Alignments SDI PDP
checked after the Vertical Division is readjusted to '2 V
or 5 V'.
• Set the Falling maintenance time to 35 µs by adjusting
R5001.
• Change the waveform position of Oscilloscope to 3SF
and then set the Falling maintenance time to 20µs by
adjusting the VR5002.
• GND maintenance section should be checked after the
Vertical Division is readjusted to '2 V or 5 V'.
Special notice: When you adjust the inclination of waveform,
do check and adjustment being based on the Reset waveform
of 1st Sub-field of 1st Frame and then move to 3rd Sub-field for
adjusting.
Adjust VR5901 to set the voltage of
Vsch [Scan high voltage ] 25V
Adjust VR5002 to set the time of
Yfr (Falling Ramp_3rd) 20 µs
(V)
20V/div.
Figure 8-39 Falling ramp
8. EN 65
50ms/div.
(t)