Alignment - Grundig CUC 7303 Serviceanleitung

Abgleich / Alignment

Alignment

All adjustment controls not mentioned in this description are adjusted during production and must not be re-adjusted in the case of repairs.
Measuring Instruments: Oscilloscope with 10:1 test probe, colour test pattern, high resistance voltmeter
Checks and adjustments after replacement or repair of:
Power Supply: alignment 1
Horizontal Deflection: alignment 2, 3
Picture Tube, CRT-Panel: alignment 2, 6
IC150: alignment 4, 5
Tuner: alignment 4, 5
Alignment
1. +A Voltage Set luminance to mimimum.
Connect the voltmeter to the cathode of D682.
2. Screen grid Feed in a grey scale test pattern.
voltage U Adjust the screen brightness so that the gradation from the
G2
darkest grey scale value to black is just still visible
(2.7V to IC150-(17)).
Set the contrast (
Measure test points R, G, B (on the CRT panel) to
determine the test point with the highest black level and
connect this point to the oscilloscope.
3. Line sharpness Select the convergence test pattern.
Contrast (
Set the brightness so that the black background of the test
pattern is just brightening.
4. Vision Feed in a generator with vision carrier 38.9MHz ca. 120mV
demodulator on tuner contact 10, 11.
(vision carrier 38.9 MHz) Vision carrier 38.9 MHz.
Norm 1 via Menü (" " –> "OK")
Voltmeter: IC850-(34)
Vision demodulator Feed in a generator with vision carrier 33.4MHz ca. 120mV
French standard on tuner contact 10, 11.
(vision carrier 33.4MHz) Norm 3 via Menü (" " –> "OK")
Voltmeter: IC850-(34)
5. Tuner AGC Feed in a standard test pattern at a channel in the upper
range of the UHF band and store it at programme position 1.
RF = 1.5mV (64dBµV, noise-free picture).
Switch the TV off with the power button.
Call up the Service Menu with remote control.
(press and hold the button " " and switching the TV on).
With "P+/P-" buttons select the menu item "AGC ALIGN".
6. White balance Feed in a FuBK test pattern.
Set the colour contrast (
Set the contrast (
Adjust the screen brightness (
from the darkest grey scale value to black is just still
visible.
3 - 2
Preparations
{
) to mid-value.
{
) to maximum.
i
) to minimum.
{
) to maximum.
v
) so that the gradation
Alignment Process
With control R654 set the voltage to
114V (14" Orion), 105V (14" Philips), 124V (15...21").
With the control U adjust the black level at the test point
G2
with the highest black level to approx. 105V...114V for 14"
picture tubes and 124V for 17...21" picture tubes.
Black level Schwarzwert
105V...114V 14"
105-110V
124V 17...21"
With the focus control U on the focusing panel adjust the
F
horizontal lines for maximum sharpness.
With filter F130 set the DC level to 2.5V.
With trimmer C136 set the DC level to 2.5V.
Repeat mutual adjustments!
With the "z - or + g" buttons tune the station so that
noise just starts to appear in the picture. Then reduce the
value so that the noise just disappears from the picture.
Terminate with " ".
Set the controls VG (R751) and VB (R771) on the CRT
panel so that no discolouration is visible in the grey scale.
CUC 7303
GRUNDIG Service