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Sharp 70GS-61SC Service Manual page 10

Pal system colour television

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70GS-61SC
• When the volume down button is pressed the top and bottom scanning decreases and
the centre scanning increases.
• Press the stand-by button on the remote control to store.
Vertical Shift
Adjust the Vertical Shift so that the picture is centred.
The effect of this adjustment is shown in figure 13.
• When the volume up button is pressed, the picture moves down.
• When the volume down button is pressed, the picture moves up.
• Press the stand-by button on the remote control to store.
Colour Adjustments
The following adjustments should only be carried out when
the CRT IC801 are replaced.
G2, Cut Off and Gain Adjustments
1. Follow the procedure below to set the G2
1.1 Tune the set to the output of a signal generator
(cross hatch pattern).
1.2 In the user menu, set contrast to 80/100 and
brightness to 40/100.
1.3 Connect the oscilloscope to the red cathode and
adjust G2 to read 140V on the sensor pulse as
in the drawing:
140 V
CH1 gnd
NOTE:
Oscilloscope should be adjusted for vertical TV field trigger
and synchronized with video signal.
2. Follow the procedure below to set the Cut Off.
2.1 Adjust G2.
2.2 Tune a white card.
2.3 Adjust colour to minimum.
2.4 Position colorimeter in the centre of screen.
2.5 Adjust brightness and contrast to obtain a lumi-
nance of ≈20 NITS.
2.6 Operate in Service Mode and select location RED
CUT OFF, GREEN CUT OFF and BLUE CUT
OFF, to obtain colour coordinates:
X=0.304 ± 0.015
To increase press volume-up button and to decrease press
volume down button.
3. Follow the procedure below to set the GAIN.
Changing NVM Data
To change the data contained within the Non Volatile
Memory, it is necessary to first select the page the data is
stored in, then the position and finally to change the data
itself. The procedure below outlines this process.
1. While on ALTER NVM PAGE, use the volume up/down
2. Press the channel up button and ALTER NVM POSITION
3. Press the channel up button and ALTER NVM VALUE
Y=0.306 ± 0.015
10
RED CUT OFF
alter «X» coordinate.
GREEN CUT OFF
alter «Y» coordinate.
BLUE CUT OFF
alter «X» and «Y» coordinate.
3.1 Using brightness and contrast buttons, select a
luminance of ≈120 NITS.
3.2 Operate in Service Mode and select location RED
GAIN, GREEN GAIN and BLUE GAIN, to obtain
colour coordinates:
X=0.304 ± 0.015
To increase press volume-up button and to decrease
press volume down button.
RED GAIN alter «X» coordinate.
GREEN GAIN alter «Y» coordinate.
BLUE GAIN alter «X» and «Y» coordinate.
3.3 Exit Service Mode and check colour coordinates
«X» and «Y» at 20 and 120 NITS. It may be nec-
essary to repeat procedure 2 and 3 of Colour
Adjustments.
buttons to change this data (data is shown in hexadecimal
format).
appears, use the volume up/down buttons to change this
data (data is shown in hexadecimal format).
appears, use the volume up/down buttons to change this
data (data is shown in hexadecimal format).
Fig.13
Y=0.306 ± 0.015

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