Philips EM5A NTSC Service Manual Download

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Electrical Alignments

EN 112

EM5A NTSC

8.3.5

Geo-Nor (Normal Geometry = Pixel Plus @ 60Hz)

Note: For all geometry alignments, use an external pattern
generator with a crosshatch pattern.

Figure 8-3 Geometry Alignments

Service tip: When the set is equipped with a rotation coil, use
this menu item to check its correct alignment. If alignment is not
correct, go to the INSTALLATION menu, choose SETUP,
press OK, and choose PICTURE TILT. With the use of a
crosshatch test pattern, align it to achieve a correct horizontal
picture.

V. slope
Aligns the zero crossing of the frame deflection to the
mechanical middle of the picture tube.
1.

First set the start conditions for 16:9 sets: 'V. S-correction'
value on '8' for the 28", '26' for the 29", '16' for the 32", or
'20' for the 36" sets. Position the boundary-stripes of the
test pattern on the edges of the picture tube.

Align 'V. slope' (during alignment, the lower half of the
picture is blanked) so that the middle line of the test pattern
is matched with the edge of the pattern transient in the
middle of the picture.

Repeat the alignment if necessary.

V. shift and V. amplitude (vertical alignment)

Aligns the vertical center and height of the picture.
1.

Use 'V. amplitude' to align the vertical amplitude so that the
entire test pattern is visible.

Set 'V. shift' to a value of '32.'

Connect a voltmeter (V

) between R3624 and “hot”

ground.

Adjust the DC voltage to '0' with potmeter R3642 (see
figure 8-1.)

Use 'V. shift' again to align the test pattern roughly vertically
in the middle of the screen.

Repeat the alignment if necessary.

V. S-correction
Aligns for equal size squares on the top, middle, and bottom of
the picture tube.
Align 'V. S-correction' so that the squares at the top (or bottom)
of the picture are the same height as the squares in the middle
of the picture.

H. shift and H. amplitude (horizontal alignment)
1.

Use 'H. amplitude' to align the horizontal amplitude so that
the entire test pattern is visible.

Use 'H. shift' to align the picture horizontally in the middle.

Repeat the 'H. amplitude' alignment if necessary.

Note: If the horizontal linearity in wide-screen mode is out
of tolerance, add a “DC-shift correction” panel (3104 328
06230) to connector 1419 of the DAF-panel [diagram I]. On
the DC-shift panel, cut diode 6433 for correction to the right
or diode 6432 for correction to the left.

Caution: Be sure to switch the set “off” first. Never plug in a
module that is not pre-aligned in a set that is on!

East/west alignment
1.

Use 'East/West Parabola' to align the vertical lines until
they are straight.

Use 'Upper East/West corner' to align the vertical lines in
the upper corners of the screen until they are straight.

Use 'Lower East/West corner' to align the vertical lines in
the lower corners of the screen until they are straight.

Use 'East/West Trapezium' to align for a rectangular
picture.

Use 'Horizontal Bow' to correct the E/W parabola so that it
is symmetrical.

Use 'Horizontal Parallelogram' to align for straight vertical
lines if necessary.

Repeat steps 1 to 6 if necessary.

8.3.6

Geo-4:3 (4:3 geometry alignment in 16:9 sets)

Use 'East/West Parabola' to align the vertical lines until
they are straight.

Use 'Upper East/West corner' to align the vertical lines in
the upper corners of the screen until they are straight.

Use 'Lower East/West corner' to align the vertical lines in
the lower corners of the screen until they are straight.

Geo-SW (Super Wide geometry alignment in 16:9 sets)
You only need to set the following values (if the normal
geometry alignment has been performed correctly):
1.

'V. S-Correction,' enter the value of the 'normal geometry'
alignment.

'H. amplitude,' enter the value of the 'normal geometry'
alignment subtracted by '1.'

'East/west Parabola,' enter the value of the 'normal
geometry' alignment.

8.3.7

Geo-HDTV (1080i alignment in 16:9 sets)

Notes:
•

This alignment is only available if the '2fH' option is 'on' and
a system compatible (1080i) signal is applied to the AV4
input.

•

For all alignments, see the alignment instruction under the
'Geo-Nor' section.

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