Alignment
All adjustment controls not mentioned in this description are pre-set at the factory and must not be re-adjusted in the case of repairs.
1. Chassis Board
Measuring instruments: Oscilloscope with 10:1 test probe.
Service works after replacement or repair of:
- Chassis alignment 1.1
- Tuner, alignment 1.2
- IF-amplifier, alignment 1.2
- 1€520, alignment 1.3 ,1.4
- Videotext (teletext), alignment 1.5
- Focusing board or CRT panel, alignment 1.6
- Vertical or horizonta! deflection, alignment 1.7
1.1 +A Voltage
This voltage must be checked after every repair and | Set the control R654 to obtain the value specified in the
before every adjustment.
general circuit diagram.
Brightness: minimum
Feed in a standard test pattern in the upper range of the | Turn control R341 (contact 14, IF-amplifier) so that noise
UHF band; the RF should be 1.5mV (64dBuV, noise-free | just starts to appear in the picture, then turn in reverse
picture) at least.
direction so that the noise just disappears from the picture.
1.2 Tuner AGC
With control R 412 setthe horizontal amplitude
to minimum. | With control
R525
set the grey picture edges to be
symmetrical within the right and left picture frame.
With R412 reset the picture width to conform with the test
pattern.
Set the control R506 so that the picture moves slowly
across the screen. Remove the short circuit.
Turn R242 slowly until the faults disappear. Do not turn any
further as the error rate may increase again.
1.3 Line phase
1.4 Line frequency
Connect the CCVS signal at capacitor C518 to ground.
1.5 Videotext
The control R242 is pre-set at the factory to minimum high-
matching
frequency emphasis.
adjustment
During this adjustment page 199 must always be selected
anew so that the page is read in anew making it possible
to evaluate the error rate.
With the focus control =~"; on the CRT panel adjust the
horizontal lines for maximum sharpness.
TV receivers with focusing panel:
Subsequently, with the focus control --- on the focusing
panel, adjust the vertical lines for maximum
sharpness.
Repeat if necessary.
Attention!
For measurements
on the focusing panel use only
sufficiently insulated measuring cables and test probes
with adequate electric strength (eg. 100:
1).
Select the convergence test pattern:
1.6 Line sharpness
Maximum contrast
Set the brightness so that the black background of the test
pattern is just brightening.
Vertical deflection:
After repair of the vertical or horizontal deflection the
picture geometry must be checked
and re-adjusted if
necessary according to the test pattern.
1.7 Picture
geometry
Vertical amplitude:
R561
Vertical frequency:
R506
Vertical linearity:
R549
Vertical Shift:
R431
Horizontal deflection:
Horizontal amplitude: R412
East/West amplitude: R422
Keystone distortion: R441
