Philips 21PT2327/79 Service Manual page 25

8.3 Alignment procedure
Perform the alignments in the following sequence:
1. B+ voltage adjustment.
2. RF AGC adjustment.
3. Screen voltage and focus adjustment.
4. White balance adjustment.
5. Pin cushion and screen width adjustment.
6. Screen centre and size adjustment (PAL).
7. Screen centre and size adjustment (NTSC).
8.3.1 B+ Voltage Test
1. Apply the specified mains voltage to the mains power input,
and a standard test pattern to the RF input.
2. Not need to adjust, just for verification: with the TV settings
in "Personal" mode (BRI/CONT/COL in middle position),
test if the voltage at D833 (B+) is 112 V ± 2.0 V.
8.3.2 RF AGC Adjustment
1. Input RF signal: 80 dBμV Color Bar signal, 100%
modulation (e.g. PM5418, RF Ampl.: 10 mV).
2. Press key "7" on the RC (in Factory Mode) to enter the RF
AGC adjustment mode.
3. Adjust the "RFAGC" item until the output of the detector
becomes 0.6 Vp-p ± 0.05 V.
8.3.3 Focus and Screen Voltage Adjustment
1. Before adjusting, please confirm that the settings are:
– Input signal: Cross Hatch test pattern
– SMART PICTURE = NATURAL.
2. Adjust the "FOCUS" potentiometer on the LOT such that
the horizontal/vertical line of 2/3 on the screen looks
thinnest. The FOCUS voltage must be within 6.6 - 7.8 kV.
3. Then adjust the "SCREEN" potentiometer on the LOT until
the horizontal line is just visible.
4. At this moment (vertical "off"), measure the VG2 voltage
with a high voltage meter and high voltage test probe
(1000:1). The VG2 voltage spec is 570 V ± 50 V.
8.3.4 White Balance Adjustment
1. Before adjusting, please confirm that the settings are:
– Input signal: Black and White test pattern
– SMART PICTURE = NATURAL.
– COLOR TEMP= NORMAL.
2. Press key "0" on the RC (in Factory Mode) to enter the
White Balance adjustment mode.
3. Use a color analyser to measure the Black part of the
screen. By changing the value of "BB" and "GB", set the
reading of the color analyser to the x,y values as given in
the next table.
4. Use a color analyser to measure the White part of the
screen. By changing the value of "BD" and "GD", set the
reading of the color analyser to the x,y values as given in
the next table.
5. Repeat these steps until you get the right color on both dark
and bright pictures (see next table).
Table 8-2 White balance adjustment values
Picture Mode Color Temp. x
Normal 11500K
Cool 15000K
Warm 8500K
Remarks:
• (*) Only adjust the NORMAL status; the COOL and WARM
offset adjustments are preset in the NVM.
If necessary, the COOL adjustments can be performed
y Y (Nit)
280 90 (white), 5 (black)
274
266 *
265 *
300 *
291 *
Alignments TC8.1A CA
with "WRCUT", "WGCUT", "WBCUT", "WGDRV", and
"WBDRV", while the WARM adjustments can be performed
via "CRCUT", "CGCUT", "CBCUT", "CGDRV", and
"CBDRV"
• When adjusting, "BB" and "GB" are used to adjust black
balance, and "BD" and "GD" are used to adjust white
balance.
8.3.5 Picture geometric adjustment
For PAL
1. Input a PAL cross hatch pattern (in NATURAL status).
2. Press key "1" on the RC (in Factory Mode) to enter the
Geometric adjustment.
3. Select "HPOS" to adjust the horizontal centre.
4. Select "VP50" to adjust the vertical centre.
5. Select "HIT" to adjust the vertical amplitude.
6. Select "VLIN" to adjust the vertical linearity.
7. Select "VSC" to adjust the vertical S-correction.
For NTSC
1. Input a NTSC cross hatch pattern (in NATURAL status).
2. Press key "1" on the RC (in Factory Mode) to enter the
Geometric adjustment.
3. Select "HPS" to adjust the horizontal center.
4. Select "VP60" to adjust the vertical center.
5. Select "HITS" to adjust the vertical amplitude.
6. Select "VLIS" to adjust the vertical linearity.
7. Select "VSS" to adjust the vertical S-correction.
Adjustment of OSD Position
1. Navigate through the "Factory Mode" options with the "CH+
(^) / CH- (v)" cursor keys on the RC (see also figure
"Factory Mode Overview").
2. Select the "OSD2" option and adjust the OSD horizontal
position, until OSD "MUTE" is at the middle of the screen.
8. EN 27